International Journal of Geo-Information

Article Effect of Compositions of MRT System Route Maps on Cognitive Mapping

Meng-Cong Zheng * and Yao-Wei Liu

Department of Industrial Design, National Taipei University of Technology, 1, Sec. 3, Chung-hsiao E. Rd., Taipei 10608, Taiwan; [email protected] * Correspondence: [email protected]; Tel.: +886-2-2771-2171 (ext. 2827)

Abstract: Route maps, common in public transportation systems, refer to thematic maps drawn according to topological concepts. To simplify complex route information, a transport network is represented using primary graphic elements. First used in 1931 with topological concepts, the octilinear design has influenced the compositions of traffic route maps to this day. The current study involved cognitive mapping research on a representative route map in Taiwan: the Metro Taipei Route Map. Through two task experiments, this study analyzed users’ cognitive behavior when using the route map and alternative route map representations. The results indicated that the route map composed of all curves resulted in higher user performance than maps using a hybrid system and the conventional octilinear system. The route map based on the hybrid system, which included a route in the shape of a perfect circle, was highly evaluated and subjectively preferred by the users. Thus, the addition of appropriate curves in route maps is beneficial for improving usability, cognitive memory, and subjective evaluation. Finally, adding travel time information to a route map effectively enhances users’ decision-making during route planning.



 Keywords: transit map; topological map; cognitive mapping; Taipei metro Citation: Zheng, M.-C.; Liu, Y.-W. Effect of Compositions of MRT System Route Maps on Cognitive Mapping. ISPRS Int. J. Geo-Inf. 2021, 1. Introduction 10, 569. https://doi.org/10.3390/ Urban expansion and development have enhanced people’s mobility. Thus, countries ijgi10080569 have implemented transit-oriented development and typically base their urban develop- ment on efficiency-improving public transport systems. However, Hickman and Wilson Academic Editor: Wolfgang Kainz indicated that the complexity of public transport systems and the random information a user might access during a journey result in public transport presenting greater uncertainty Received: 5 July 2021 than general road transport [1]. Morrison emphasized transit map representation with Accepted: 20 August 2021 Published: 23 August 2021 simple geometric lines based on topological concepts [2]; this approach enables users to monitor their progress and switch routes more easily while also rapidly understanding

Publisher’s Note: MDPI stays neutral that the route map is not drawn to scale. Nevertheless, a user might overlook distorted with regard to jurisdictional claims in route map information caused by the map not being drawn to scale. A survey by Guo [3] published maps and institutional affil- revealed that passengers overlooking distorted route map information could spend up iations. to twice more time on transportation than they expected.” Past studies showed distances between stations on a metro route map affected the users’ decision-making regarding their public transport route; difference between a route map and the actual distance traveled might limit people’s ability to avoid crowded routes. Thus, the layout design of a route map impacts decision-making, but the way the features are portrayed also affects people’s Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. route selection. Accordingly, a transit map could potentially become a planning tool to This article is an open access article solve operational problems and improve system. distributed under the terms and Any type of map is composed of numerous basic visual elements; a designer employs conditions of the Creative Commons diverse symbols to represent the characteristics of a certain space. The visualization process, Attribution (CC BY) license (https:// or thinking by incorporating visual images into thought, occurs to the fullest when seeing, creativecommons.org/licenses/by/ imagining, and graphic ideation come into active interplay [4,5]. The point, line, and area 4.0/). can be regarded as the most basic graphic elements in a map [6]. Schematic transport

ISPRS Int. J. Geo-Inf. 2021, 10, 569. https://doi.org/10.3390/ijgi10080569 https://www.mdpi.com/journal/ijgi ISPRS Int. J. Geo-Inf. 2021, 10, x FOR PEER REVIEW 2 of 27

ISPRS Int. J. Geo-Inf. 2021, 10, 569 seeing, imagining, and graphic ideation come into active interplay [4,5]. The point, line,2 of 24 and area can be regarded as the most basic graphic elements in a map [6]. Schematic transport maps usually have all routes drawn as straight lines. Lines vary in direction via fixed, stylized angles, commonly 45 and 90 degrees or 30, 60, and 90 degrees, or are sim- plifiedmaps with usually arbitrary have angles. all routes Overlapping drawn as straightroutes are lines. separated Lines varyby a minimum in direction legibility via fixed, distance,stylized which angles, can commonly be zero or 45a constant and 90 degreeschosen for or 30,the 60,particular and 90 map. degrees, Adjacent or are schema- simplified with arbitrary angles. Overlapping routes are separated by a minimum legibility distance, tized lines can have smooth, artistic, circular arcs around bends, preserving their graphic which can be zero or a constant chosen for the particular map. Adjacent schematized lines proximity distance for the greatest length possible. A small number of breaks or changes can have smooth, artistic, circular arcs around bends, preserving their graphic proximity in line direction can provide better visualization and add a sense of the original geometry distance for the greatest length possible. A small number of breaks or changes in line [7]. In at least one study using thematic maps, the balance of the map’s elements is shown direction can provide better visualization and add a sense of the original geometry [7]. In to have an initial effect on the way the map reader goes about looking at those elements at least one study using thematic maps, the balance of the map’s elements is shown to have [8]. an initial effect on the way the map reader goes about looking at those elements [8]. In terms of transport, designing high-quality route maps involves particular con- In terms of transport, designing high-quality route maps involves particular concerns. cerns. Route map design first gained attention in 1931 when Henry Beck used topological Route map design first gained attention in 1931 when Henry Beck used topological concepts concepts to draw a map of the London Underground using 0°, 45°, and 90° angles. That to draw a map of the London Underground using 0◦, 45◦, and 90◦ angles. That map map exerts an effect to this day. Wolff [9] referred to the design principles of Beck’s map exerts an effect to this day. Wolff [9] referred to the design principles of Beck’s map as as “octilinearity”“octilinearity” andand indicatedindicated that that the the modality modality could could effectively effectively make make route route maps maps neat neat and andorganized organized (Figure (Figure1). 1). However, However, through through the the method method of of cognitive cognitive mapping, mapping, Vertesi Vertesi [ 10 ] [10]found found that that octilinear octilinear route route maps maps significantly significantly affected affected Londoners’ Londoners’ spatial spatial cognition cognition and andthe the approach approach they they employed employed to determineto determine their their routes, routes, i.e., routei.e., route maps maps formed formed the basis the of basisindividuals’ of individuals’ spatial spatial cognition cognition in their in brains.their brains.

Figure 1. Schematic of octilinear route directions (Wolff, 2007). Figure 1. Schematic of octilinear route directions (Wolff, 2007). Route maps are a tool for route planning. Robert et al. [11] argued that these maps areRoute aimed maps at reducing are a tool cognitive for route load planning. during tripRobert planning. et al. [11] They argued should that facilitate these straight-maps areforward aimed at and reducing rapid reconstructioncognitive load ofduring a route trip if planning. planning fails.They Heshould also indicatedfacilitate straight- numerous forwardvaluable and design rapid reconstruction suggestions in of route a route maps if planning based on fails. the conventionalHe also indicated octilinear numerous design, valuablesuch as design font and suggestions line width, in maintaining route maps a ba neatsed layout, on the and conventional extending octilinear line segments. design, Even suchso, as there font areandstill line somewidth, conditions maintaining to a be ne awareat layout, of. and For example,extending mapline segments. scale is relatively Even so,large there inare the still inner some city, conditions where to many be aware routes of. converge For example, and map connect; scale stopsis relatively in the large central in businessthe inner districtcity, where might many be only routes four conver or fivege blocksand connect; apart, andstops a in larger the central scale is business needed to districtaccommodate might be allonly route four lines or five and blocks station apart, names and and a to larger facilitate scale path is needed finding to [12 accommo-,13]. Robert dateet al.all [route14] further lines and proposed station three names types and of to route facilitate map path compositions finding [12,13]. to perform Robert a usability et al. [14]comparison further proposed between three conventional types of route official ma routep compositions maps and all-curve to perform designs a usability (i.e., replacing com- parisonall straight between lines conventional and angles official with smooth route maps curves). and The all-curve results designs indicated (i.e., that replacing none of all the straightdesign lines rules and could angles be regarded with smooth as the curves). gold standard; The results when indicated route maps that based none onof the octilinear de- signdesign rules becomecould be ineffective regarded as under the gold certain standard; circumstances, when route design maps approaches based on octilinear that depart designfrom become conventional ineffective concepts under are likelycertain to circ resultumstances, in usability design enhancements. approaches Nagao that depart et al. [15 ] fromfound conventional that users concepts could accomplish are likely to their result route in usability search enhancements. and planning evenNagao in et a al. complex [15] foundtransport that users network could as accomplish long as they their grasped route keysearch information and planning such even as routes, in a complex stops, and transporttransfer network stations. as Their long study as they revealed grasped that key concise information graphics such comprising as routes, circular stops, lines and as transferwell as stations. vertical Their and horizontalstudy revealed key routes that concise helped graphics users build comprising their spatial circular cognition lines as and that route maps should be designed in accordance with local conditions. A schematic map is a common communication map [16] and is a type of thematic map containing considerable geographic information. A simple, comprehensive definition of ‘schematic map’ is difficult to determine. According to Oke and Siddiqui’s study [14], a

schematic map is a linear cartogram of a given network. Schematic diagrams use symbolic ISPRS Int. J. Geo-Inf. 2021, 10, 569 3 of 24

representations of pathways to reduce complexity and ease orientation in a network. How are schematic maps produced? Drafting software is often applied to support the map drawings by computer. In general, the original road network is scanned or digitized to be used as background to the drawing and design of the new schematized lines. This method requires the same degree of visual scrutiny as the manual one, because it is still a procedure of trial-and-error attempts, but results can be obtained more quickly, attempts can be stored, and output to paper can be easily arranged [17]. The cartographic literature offers some guidance for representing thematic data on routes but is apparently barren of guiding cartographic principles for the depiction of point data on routes [18]. However, the key method for conveying spatial knowledge in route maps differs from that of general map designs because route maps topologize and simplify actual geographical conditions. Route maps are commonly employed in the systems of various public transport tools; thus, understanding how route map composition affects cognitive mapping is essential. The Metro Taipei Route Map was selected as the object of this study. Composed of five routes, Taipei’s metro system is currently the public transport system in Taiwan with the highest usage frequency and with an average daily ridership over 2.1 million. In this study, we first observed the route map of Taipei’s metro system and investigated proposals for new designs, to identify key factors affecting users’ cognition. Subsequently, we observed users’ cognitive memory and behavior regarding route maps and used diverse design approaches to examine the relationships between route map composition and cognitive mapping. Finally, references and suggestions for future route map design were provided based on the research findings.

2. Materials and Methods The route map of Taipei Metro, which has the largest number of converged routes and the highest ridership in Taiwan, was selected as the research object. To determine the usage status of the targeted route map, nonparticipant observation and behavior mapping were used to observe the public’s usage frequency and behavior. We made nonparticipant observation at specific Taipei Metro stations, recorded 100 users who using the route map, and interviewed them about their usage habits and suggestions. We noted that the hot zones that the users’ paid most attention to were largely concentrated on the dense transfer stations around Taipei Main Station on the route map. This map is used every 1.3 min on average on weekends and once every 2.1 min on weekdays based on our observation. When passengers stop to check the route map, they often also use their cell phones, discuss the matter with their companions, and observe the actual environment. In the survey, the users responded that the route map did not provide information on the travel time between stations, which hampered their ability to perform optimal journey planning within limited time.

2.1. Experiment 1: Cognitive Mapping and Route Planning Using the Metro Taipei Route Map We used route maps (length = 130 cm; width = 95.3 cm) provided by the Taipei Rapid Transit Corporation, which were pasted on the walls at metro stations at an average height of 88 cm above the ground; the visibility range was between 30 cm and 125 cm from the wall (Figure2). In total, 32 users (16 men and 16 women) aged 16–64 years with experience using Taipei’s metro system were invited for Experiment 1. They all have university degrees. The experimental steps were as follows: (1) providing demographic information and completing an experience questionnaire; (2) performing cognitive mapping using the current route map as well as completing three tasks involving route search and three tasks involving route planning; (3) completing the Usability Metric for User Experience (UMUX) scale. ISPRS Int. J. Geo-Inf. 2021, 10, x FOR PEER REVIEW 4 of 27

ISPRS Int. J. Geo-Inf. 2021, 10, 569 4 of 24 current route map as well as completing three tasks involving route search and three tasks involving route planning; (3) completing the Usability Metric for User Experience (UMUX) scale.

FigureFigure 2. 2. PresentPresent route route map. map.

2.2.2.2. Experiment 2: 2: Comparison Comparison and and Evaluation Evaluation of ofNew New Designs Designs for forthe theMetro Metro System System Route Route Map Map After analyzing users’ cognitive mapping regarding regarding the the current current route route map map through through the findingsthe findings of Experiment of Experiment 1, we 1, we proposed proposed three three new new versions versions of of the the metro metro system system route route map. Consideringmap. Considering that severalthat several routes routes in the in Greaterthe Greater Taipei Taipei Area Area were were under under construction construction and to includeand to include them in them the future in the drawing,future drawing, the composition the composition of the routeof the maps route formaps Experiment for Experi- 2 was changedment 2 was to achanged landscape to a perspectivelandscape perspective (i.e., horizontal; (i.e., horizontal; length = 95.3length cm; = 95.3width cm; = width 65 cm )= and comprised65cm) and comprised Map A, Map Map B, A, and Map Map B, C.and Before Map C. each Before participant each participant engaged engaged in the experiment, in the aexperiment, route map wasa route stuck map to was the wallstuck according to the wall to according their ideal to eye-level their ideal height. eye-level Prior height. horizontal routePrior maphorizontal studies route have map indicated studies that have the indicated optimal heightthat the above optimal the groundheight above was 123.2 the cm (Figureground3 was). Participants 123.2 cm (Figure in Experiment 3). Participants 2 preferred in Experiment the center 2 of preferred the drawing the center at an of eye-level the heightdrawing of at 155.7 an eye-level cm above height the of ground. 155.7 cm Thirty above users the ground. aged between Thirty users 16 and aged 64 between years with experience using Taipei’s metro system were invited for this experimental phase. They all have university degrees and did not join Experiment 1 before. The participants were divided into three groups, with each group comprising 10 persons based on Zheng’s

evidence-based study [19], including five men and five women. Each participant used only one proposed route map for their experimental task. The experiment involved four steps: (1) A demographic information questionnaire, (2) Four route planning and cognitive ISPRS Int. J. Geo-Inf. 2021, 10, x FOR PEER REVIEW 5 of 27

16 and 64 years with experience using Taipei’s metro system were invited for this experi- mental phase. They all have university degrees and did not join Experiment 1 before. The participants were divided into three groups, with each group comprising 10 persons ISPRS Int. J. Geo-Inf. 2021, 10, 569 based on Zheng’s evidence-based study [19], including five men and five women. Each5 of 24 participant used only one proposed route map for their experimental task. The experiment involved four steps: (1) A demographic information questionnaire, (2) Four route plan- mappingning and tasks, cognitive including mapping long tasks, and short-distance including long routes and short-distance to understanding routes users’ to under- diversity planning,standing (3)users’ A route diversity map planning, evaluation (3) scale, A route and map (4) Routeevaluation map preferencescale, and (4)Route ranking. map preference ranking.

FigureFigure 3.3. New route maps design. design.

3. Results 3.1. Results on Cognitive Mapping The participants’ drawing order was recorded on video. We found that 68.8% of the participants drew metro routes first before drawing specific points (e.g., stations, transfer stations, or terminal stations) and annotated station names before extending other routes from a transfer station. Notably, all the participants drew the horizontally oriented Blue line first, the vertically oriented Red line next, and then other routes. The first station drawn by 46.9% of the participants was Taipei Main Station where the Blue line and Red line intersect ISPRS Int. J. Geo-Inf. 2021, 10, 569 6 of 24

(Table1). Taipei Main Station was annotated by 30 of the 32 participants. In fact, according to metro statistics, the Blue line and Red line are the routes in the Taipei Metro with the highest and the second highest ridership, respectively. Thus, Taipei Main Station, being located at the center of the route map and with the highest ridership, was prominently placed in the participants’ drawing order. This indicated that for the participants in this cognitive mapping, the location where the horizontal and vertical lines intersected, at Taipei Main Station, was their most familiar and definite knowledge point regarding the route map.

Table 1. Statistical results for drawing order.

Item Total (Persons) Percentage of Persons (%) Point–line 10 31.2% Line–point 22 68.8% Taipei Main Station as the first station drawn 15 46.9%

Overall, 71.9% of the participants opted to use rounded corners to depict the turning points of the metro lines. This finding corresponds with that of Nagao et al. [9] who indicated that rounded corners at route turning points are critical for representing route continuation. This finding indicated that rounded corners on a route map facilitated the representation of route extensions; these rounded corners could also be turned into large rounded corners and even curves to represent route orientations to support a person’s cognitive memory. Three types of compositions were identified based on participants’ drawing of lines and turning points on a route map: straight lines and corners (SCs), straight lines and rounded corners (SRs), and curved and rounded corners (CRs). Most participants used CRs for representations on the cognitive map. Among the participants using SCs, SRs, and CRs, a significant difference was observed between drawing points first and drawing lines first (p = 0.015 [<0.05]). Those using SCs all drew lines first and ISPRS Int. J. Geo-Inf. 2021, 10, x FOR PEER REVIEW 7 of 27 points next; a third of those using SRs drew lines first and points next; half of those using CRs drew lines first and points next (Table2).

Table 2. Percentage of participants using each composition type in cognitive mapping.mapping.

StraightStraight Lines Lines and CornersCorners (SCs) (SCs) Straight Straight Lines Lines andand RoundedRounded Corners Corners (SRs) (SRs) Curved Curved and and Rounded Corners Corners (CRs) (CRs) 28.1%28.1% (person)(person) 25.0% (person) (person) 46.9% (person)(person)

The following elements used by the participants when drawing a cognitive route map were assessed: use of color, use of transfer stations, use of terminal stations, and use of graphics; these elements were used to facilitate memorization when representing infor- mation on the drawing. The results are summarized in Table 3.

Table 3. Statistical results on the most frequently used elements in drawing a route map based on cognitive mapping.

Item Persons Percentage of Participant (%) Using color 29 90.6.% Using the five correct colors (one for each 22 68.8% metro line) Using transfer stations 31 96.9% Accuracy rate over 50% 16 50.0% Using terminal stations 30 93.8% Accuracy rate over 50% 20 62.5% Using graphic features of route forms 29 90.6% Using transfer stations on branch lines 18 56.3% Using routes beyond the system 9 28.1% Using landmarks or bodies of water 10 31.3%

In drawing the cognitive route map, 90.6% of the participants used colors to facilitate memorization; 68.8% of these participants used the five correct colors to draw the five main routes. The number of women using colors was significantly higher than that of men using colors (p = 0.003 [<0.05]), indicating that color was among the factors related to par- ticipants’ memory of the route map. We found that among the elements used by the par- ticipants, transfer stations, terminal stations, and features of route forms were widely used. Overall, 96.9% of the participants drew transfer stations, and 93.8% drew terminal stations. The percentage of those who drew transfer stations was significantly correlated with the participants’ metro usage experience (p = 0.0016 [<0.05]) (Table 3). Participants taking the metro more frequently drew more transfer stations, and those who drew more

ISPRS Int. J. Geo-Inf. 2021, 10, 569 7 of 24

The following elements used by the participants when drawing a cognitive route map were assessed: use of color, use of transfer stations, use of terminal stations, and use of graphics; these elements were used to facilitate memorization when representing information on the drawing. The results are summarized in Table3.

Table 3. Statistical results on the most frequently used elements in drawing a route map based on cognitive mapping.

Item Persons Percentage of Participant (%) Using color 29 90.6% Using the five correct colors (one for each 22 68.8% metro line) Using transfer stations 31 96.9% Accuracy rate over 50% 16 50.0% Using terminal stations 30 93.8% Accuracy rate over 50% 20 62.5% Using graphic features of route forms 29 90.6% Using transfer stations on branch lines 18 56.3% Using routes beyond the system 9 28.1% Using landmarks or bodies of water 10 31.3%

In drawing the cognitive route map, 90.6% of the participants used colors to facilitate memorization; 68.8% of these participants used the five correct colors to draw the five main routes. The number of women using colors was significantly higher than that of men using colors (p = 0.003 [<0.05]), indicating that color was among the factors related to participants’ memory of the route map. We found that among the elements used by the participants, transfer stations, terminal stations, and features of route forms were widely used. Overall, 96.9% of the participants drew transfer stations, and 93.8% drew terminal stations. The percentage of those who drew transfer stations was significantly correlated with the participants’ metro usage experience (p = 0.0016 [<0.05]) (Table3). Participants taking the metro more frequently drew more transfer stations, and those who drew more transfer stations also drew more terminal stations (r = 0.74 **, strong correlation). The participants who drew lines first and points next annotated more transfer stations than did those who drew points first and lines next (p = 0.0418). This finding indicated that transfer and terminal stations were crucial elements in the cognitive route maps in the participants’ minds, in the drawing process. Most participants tended to annotate a transfer station before adding details on the cognitive route map of an area. Regarding participants’ rate of drawing transfer stations, we found that it was the highest for Taipei Main Station and then tended to decrease with distance from this main transit station (Table4). Participants’ cognitive memory of terminal stations was relatively similar. The results revealed that most participants were influenced by the distribution and locations of these stations on the map drawing. For example, Tamsui metro station, which was located on the top of the vertical orientation, and Taipei Nangang Exhibition Center metro station, which was located at the far right of the drawing and had memorization graphics, were the most frequently drawn terminal stations (Table5). ISPRS Int. J. Geo-Inf. 2021, 10, x FOR PEER REVIEW 8 of 27

This finding indicated that transfer and terminal stations were crucial elements in the cognitive route maps in the participants’ minds, in the drawing process. Most participants tended to annotate a transfer station before adding details on the cognitive route map of ISPRS Int. J. Geo-Inf. 2021, 10, 569 an area. Regarding participants’ rate of drawing transfer stations, we found that it was8 of 24the highest for Taipei Main Station and then tended to decrease with distance from this main transit station (Table 4). Table 4. Frequency and distribution of transfer stations as a drawing element. Table 4. Frequency and distribution of transfer stations as a drawing element. Transfer Station Transfer Station StationStation Name Name FrequencyFrequency TaipeiTaipei Main Main Station Station (BL/R) (BL/R) 3131 ZhongxiaoZhongxiao Xinsheng Xinsheng (BL/O) (BL/O) 2222 ZhongxiaoZhongxiao Fuxing Fuxing (BL/BR) (BL/BR) 2020 XimenXimen (BL/G) (BL/G) 2020 TaipeiTaipei Nangang Nangang Exhibition Exhibition Center Center (BL/BR) (BL/BR) 1919 Zhongshan (R/G) 15 Zhongshan (R/G) 15 Dongmen (R/O) 15 Dongmen (R/O) 15 Chiang Kai-Shek Memorial Hall (R/G) 13 Chiang Kai-ShekSongjiang Memorial Nanjing Hall (O/G) (R/G) 1312 SongjiangGuting Nanjing (O/G) (O/G) 1211 GutingDaan (O/G) (R/BR) 1111 NanjingDaan (R/BR)Fuxing (G/BR) 1111 NanjingMinquan Fuxing w. (G/BR)Rd. (R/O) 1111 Minquan w. Rd. (R/O) 11

Total 211 Total 211

ISPRS Int. J. Geo-Inf. 2021, 10, x FOR PEER REVIEW 9 of 27

Participants’ cognitive memory of terminal stations was relatively similar. The re- Table 5. Frequency and distribution of terminal stations as a drawing element. Tablesults 5. Frequency revealed and that distribution most participants of terminal were stations influenced as a drawing by the element. distribution and locations of Transferthese Station stations on the map drawing. For example, Tamsui metro station, which was located Transfer Station Station Nameon the top of the Frequencyvertical orientation, and Taipei Nangang Exhibition Center metro station, Station Name which was locatedFrequency at the far right of the drawing and had memorization graphics, were Tamsui (R) 27 Tamsui (R) the most frequently27 drawn terminal stations (Table 5). TaipeiTaipei Nangang Nangang ExhibitionExhibition Center Center (BL) (BL) 27 27 TaipeiTaipei Nangang Nangang ExhibitionExhibition Center Center (BR) (BR) 21 21 TaipeiTaipei ZooZoo (BR) (BR) 20 20 Xiangshan (R) 19 Xiangshan (R) 19 Nanshijiao (O) 18 Nanshijiao (O) 18 Songshan (G) 17 Songshan (G) 17 Xindian (G) 16 LuzhouXindian (G)(O) 14 16 HuilongLuzhou (O) (O) 11 14 DingpuHuilong (BL) (O) 9 11 Dingpu (BL) 9

Total 199 Total 199

In total, 90.6% of the participants used at least one type of graphic to facilitate memory as they drew the routes. Most participants stated that they could memorize clearly the graphics formed by the routes on the map, such as the square shape formed by the Brown line in the upper right and the forked shape of the route to the left of the draw- ing, which ended in two terminal stations. The results revealed that 75% of the partici- pants drew an obvious square shape (A) in figure X in the upper right of the drawing, and 68.8% of the participants drew a forked shape (B) in figure X to the left of the drawing. A few participants drew the shape of the central part (C) in figure X and a triangular shape (D), accounting for 12.5% and 6.3% of all drawings, respectively (Figure 4). As the participants were drawing the cognitive route map, we found that the partic- ipants were often uncertain about whether the routes involved turning points, as indi- cated by observations such as “in my memory, this route leads to the lower left corner,” “this should be straight,” and “I remember there was a turning point here.” Some partic- ipants stated that they particularly remembered the turning points of routes or intersec- tions involving transfer stations. ISPRS Int. J. Geo-Inf. 2021, 10, 569 9 of 24

In total, 90.6% of the participants used at least one type of graphic to facilitate memory as they drew the routes. Most participants stated that they could memorize clearly the graphics formed by the routes on the map, such as the square shape formed by the Brown line in the upper right and the forked shape of the route to the left of the drawing, which ended in two terminal stations. The results revealed that 75% of the participants drew an obvious square shape (A) in figure X in the upper right of the drawing, and 68.8% of the participants drew a forked shape (B) in figure X to the left of the drawing. A few ISPRS Int. J. Geo-Inf.participants 2021, 10, x drewFOR PEER the REVIEW shape of the central part (C) in figure X and a triangular shape (D), 10 of 27 accounting for 12.5% and 6.3% of all drawings, respectively (Figure4).

Figure 4. GraphicFigure memory 4. Graphic usage memory percentage usage percentage in terms of in drawing terms of elements.drawing elements.

In summary, we found that most of the participants first drew routes and then sta- tions, and almost all the participants designated routes using various colors. In the partic- ipants’ cognitive mapping, they employed three types of route composition, namely SCs, SRs, or CRs, to represent the graphic features of the routes, and they annotated transfer stations and terminal stations. Regarding the participants’ route map drawing order, they drew graphics of routes and areas first, followed by annotation of transfer stations at route

ISPRS Int. J. Geo-Inf. 2021, 10, 569 10 of 24

As the participants were drawing the cognitive route map, we found that the partici- pants were often uncertain about whether the routes involved turning points, as indicated by observations such as “in my memory, this route leads to the lower left corner,” “this should be straight,” and “I remember there was a turning point here.” Some participants stated that they particularly remembered the turning points of routes or intersections involving transfer stations. In summary, we found that most of the participants first drew routes and then stations, and almost all the participants designated routes using various colors. In the participants’ cognitive mapping, they employed three types of route composition, namely SCs, SRs, or CRs, to represent the graphic features of the routes, and they annotated transfer stations and terminal stations. Regarding the participants’ route map drawing order, they drew graphics of routes and areas first, followed by annotation of transfer stations at route intersections as well as the start and terminal stations of the routes (Table6). Although they were not statistically significant, we will be comparing the subsequent three map proposals in particular.

Table 6. Cross comparison of drawing approach and drawing elements.

Straight Lines and Corner Straight Lines and Curved and Rounded Corner Element/Drawing Approach (SC) Rounded Corner (SR) (CR) Color use percentage 80% (of the participants) 85.7% (of the participants) 100% (of the participants) Mean transfer stations used 6 (persons) 6.3 (persons) 7.1 (persons) Mean terminal stations used 4.6 (persons) 6 (persons) 5.5 (persons) Mean memorization shapes used 1.4 (persons) 2 (persons) 1.6 (persons)

A metro route map was gradually constructed with points, lines, and areas. Greater metro usage experience enabled participants to draw more transfer and terminal stations. Taipei Main Station was not only the station most frequently annotated but also the station typically annotated first. At route turning points, 68.8% of the participants opted to use rounded corners to represent the turning, revealing that the rounded corners on the route map facilitated route representation and supported the participants’ cognitive memorization (Figure4).

3.2. Results on Route Tasks We referenced the basic elements of route map composition proposed by Nagao et al. [15]; thus, stations, routes, and transfer station served as the items for classification. Based on the model of route description and analysis of Brosset [20], we coded the elements of composition to facilitate the conversion of the routes planned by the participants into a visualized route planning model. We employed two types of route tasks: (1) route planning with designated start and end stations and (2) route planning with designated start and end stations with the requirement of passing three designated stations on the way. Each type of route task involved three subtasks; the participants were instructed to plan the route that they considered the fastest (routes with the fewest transfers or stops). We want to understand how users base their route planning on distance, travel time, or the number of transfers between different distances’ start and end station. (1) Route planning task with designated start and end stations In Tasks Q1, Q3, and Q5, the participants were instructed to plan routes with desig- nated start and end stations. Task Q1 required two transfers; for the first transfer, three transfer stations were available for selection, and for the second transfer, only one trans- fer station was available. Task Q3 required one transfer, and two transfer stations were available for selection. Task Q5 required one transfer, and only one transfer station was available. The experimental results indicated that in more complex tasks, the participants spent more time on planning. Although all the participants planned routes with the fewest ISPRS Int. J. Geo-Inf. 2021, 10, 569 11 of 24

transfers in Tasks Q1, Q3, and Q5, only in Task Q5, with the simplest route, did all the participants plan routes with the fewest stops. In Task Q3, 81.25% of the participants used routes with the fewest stops, whereas in Task Q1, only 34.38% of the participants employed this approach; notably, some participants exhibited large deviations from the average. This indicated that a larger number of necessary transfers and transfer station options resulted in a lower percentage of the participants being capable of planning routes with the fewest stops. In the current route map, using multiple transfers was challenging. Regarding transfer station options, the last available transfer station tended to be selected for transfer ISPRS Int. J. Geo-Inf. 2021, 10, x FOR (56%PEER REVIEW of the participants in Task Q1; 81% of the participants in Task Q3). The participants12 of 27

tended to select transfer stations closer to the end station (Figure5).

100% 000%

80% 59% 60% 81% 100% 40% 28% 20% 6% 19% 0% 6% 0%0 Q1 (three transfer sations on the route) Q3 (two transfer sations on the route) Q5 (one transfer sation on the route)

end transfer station first transfer station middle transfer station detours only one transfer station

FigureFigure 5.5. LocationsLocations ofof thethe selectedselected transfertransfer stations.stations. (2)(2) Route planning tasks withwith designateddesignated startstart andand endend stationsstations andand thethe requirementrequirement ofof passing threethree designateddesignated stationsstations (Q2,(Q2, Q4,Q4, andand Q6)Q6) InIn TasksTasks Q2,Q2, Q4, Q4, and and Q6, Q6, the the participants participants couldcould decidedecide thethe orderorder inin whichwhich theythey passpass thethe threethree requiredrequired stations. stations. Thus,Thus, inin additionaddition toto consideringconsidering the the start start andand endend stations,stations, the the routeroute planningplanning involvedinvolved simultaneouslysimultaneously consideringconsidering thethe locationslocations ofof fivefive stations. stations. TheThe startingstarting pointpoint inin TaskTask Q2Q2 was was the the southernmost southernmostof ofall all tasks. tasks. AmongAmong thethe fivefivestations, stations,the the distancedistance between the the southernmost southernmost and and northern northernmostmost stations stations was was much much longer longer than than that thatbetween between the easternmost the easternmost and andwesternmost westernmost statio stations.ns. Therefore, Therefore, the participants the participants had to had fo- tocus focus on vertical on vertical routes. routes. The results The results indicated indicated that 53% that of 53% the ofparticipants the participants chose chosethe south- the southernmosternmost station station as their as start their station start station and moved and moved northward northward before returning before returning to the end to thestation end in station the center. in the The center. starting The startingpoint in pointTask inQ4 Task was Q4the waswesternmost. the westernmost. The distance The distancebetween betweenthe easternmost the easternmost and westernmost and westernmost stations was stations much was longer much than longer that than between that betweenthe southernmost the southernmost and theand northernmost the northernmost stations. stations. Thus, Thus,the journey the journey involved involved more more hori- horizontalzontal routes. routes. The The results results indicated indicated that that 72% 72% of of the the participants participants opted opted to start fromfrom thethe westernmostwesternmost station station and and move move toward toward stations stations to to the the east east before before returning returning to the to the end end station sta- intion the in center. the center. In Task In Task Q6, the Q6, distance the distance between between the easternmost the easternmost and westernmostand westernmost stations sta- wastions only was slightly only slightly longer longer than thatthan between that between the southernmost the southernmost and northernmost and northernmost stations. sta- Thetions. results The results revealed revealed that 50% that of 50% the participants of the participants opted to opted start fromto start the from easternmost the easternmost station andstation move and westward. move westward. Because Because the participants the participants planned planned routes accordingroutes according to the locations to the lo- ofcations the given of the five given stations, five stations, most of themmost plannedof them planned their routes their according routes according to the distances to the dis- of thesetances locations of these to locations avoid detours. to avoid In thisdetours. manner, In this more manner, efficient more routes efficient were planned, routes were the numberplanned, of the stops number passed of generally stops passed decreased, generally and thedecreased, time required and the was time shorter. required was shorter.In addition to avoiding detours, another factor in planning was the number of transfers. For example,In addition in Task to avoiding Q4 between detours, the Nanjing another Fuxing factor and in planning Taipei Nangang was the Exhibition number of Center trans- stationsfers. For (Figureexample,6), in one Task additional Q4 between transfer the Na wasnjing required Fuxing whenand Taipei 60% ofNangang the participants Exhibition optedCenter to stations detour downward;(Figure 6), one 40% additional of the participants transfer was chose required to detour when upward, 60% of requiring the partici- no transfer,pants opted but theyto detour had to downward; pass four additional 40% of the stations. participants Convenient chose to transfer detour wasupward, the greatest requir- considerationing no transfer, for but the they few had participants to pass four with additional less experience stations. of Conven using theient metro transfer who was rather the greatest consideration for the few participants with less experience of using the metro who rather detoured; this finding indicated that route planning that reduces detours and the number of transfers was important for route map readers (Table 7). Although route maps based on topology mainly represented relationships between stations and routes, geo- graphic locations were not depicted accurately. Route maps were not to scale, but the lo- cation of each station marked on them remains the basis for map readers in determining to detour or not.

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detoured; this finding indicated that route planning that reduces detours and the number of transfers was important for route map readers (Table7). Although route maps based on topology mainly represented relationships between stations and routes, geographic locations were not depicted accurately. Route maps were not to scale, but the location of ISPRS Int. J. Geo-Inf. 2021, 10, x FOR PEER REVIEW 13 of 27 each station marked on them remains the basis for map readers in determining to detour or not.

Figure 6. Overall, 60% of of the the participants participants opted opted to to detour detour downwa downward,rd, which which required required an an additi additionalonal transfer, transfer, whereas 40% of the participants chose to detour upward and had to pass fourfour additionaladditional stations.stations.

The responsesresponses toto Q1 Q1 to to Q6 Q6 revealed revealed that that in planning in planning routes, routes, the participants the participants attempted at- temptedto minimize to minimize as much as as much possible as possible the estimated the estimated time required time required by their by route their of route choice. of choice.Visualization Visualization analysis analysis conducted conducted based on based a route on planning a route planning model revealed model therevealed following the patterns in the participants’ route selections: following patterns in the participants’ route selections: 1. Avoiding station that involves a change of traveling direction in the selected route. 1. Avoiding station that involves a change of traveling direction in the selected route. 2. Decreasing the number of transfers along the selected route. 2. Decreasing the number of transfers along the selected route. 3. Selecting transfer stations closer to the end station. 3. Selecting transfer stations closer to the end station. 4. Selecting movement directions from the top to the bottom or from the left to the right 4. Selecting movement directions from the top to the bottom or from the left to the in the drawing and avoiding the complex central area. right in the drawing and avoiding the complex central area. Since the Taipei MRT route map has been widely used, the 32 participants in Exper- imentTable 1 were7. Cluster divided analysis into based four on groups participants’ according experience. to their metro usage experience and frequency using cluster analysis: low experience and infrequent use, low experience and Average frequent use, high experienceShortest andLongest infrequent use, and high experienceAccuracy and frequentError in use. Times of Time to Total Time Percentage UsageThe findings revealedTime that for as theTime participants’ for experience of takingRate the metroof Estimated decreased, Group. the timeUse spent per on route search and planningComplete increased. As thefor level of experience increased, of Persons Experience Transfer Transfer Search Travel althoughWeek the speed of route search and planningPlanning increased, Answering the participants easily misiden- Search Search Task Time tified stations and consequently gave wrongTask answers. Analysis of the results for “total LSIU 9.4% 1.3ytime for answering,”1.2t 218s “accuracy rate375.3s of search182.0s task,” and1139.3s “error in estimated100% travel±55.4% time” LSFU 34.4% 0.9yindicated no5.3t significant 230.8s correlations 310.9s among the166.0s four groups1039.8s (Table 7).69.7% ±27.6% HSIU 28.1% 8.4y 2.9t 200.4s 281.7s 170.9s 994.8s 72.2% ±32.0% HSFU 28.1% 8.4y 6.2t 219.6s 329.3s 139.6s 967.6s 79.6% ±34.4% LSIU, low experience and infrequent use; LSFU, low experience and frequent use; HSIU, high experience and infrequent use; HSFY, high experience and frequent use.

Since the Taipei MRT route map has been widely used, the 32 participants in Exper- iment 1 were divided into four groups according to their metro usage experience and fre-

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Table 7. Cluster analysis based on participants’ experience.

Shortest Longest Accuracy Error in Times of Average Time Total Time Percentage Usage Time for Time for Rate of Estimated Group Use per to Complete for of Persons Experience Transfer Transfer Search Travel Week Planning Task Answering Search Search Task Time LSIU 9.4% 1.3 y 1.2 t 218 s 375.3 s 182.0 s 1139.3 s 100% ±55.4% LSFU 34.4% 0.9 y 5.3 t 230.8 s 310.9 s 166.0 s 1039.8 s 69.7% ±27.6% HSIU 28.1% 8.4 y 2.9 t 200.4 s 281.7 s 170.9 s 994.8 s 72.2% ±32.0% HSFU 28.1% 8.4 y 6.2 t 219.6 s 329.3 s 139.6 s 967.6 s 79.6% ±34.4% LSIU, low experience and infrequent use; LSFU, low experience and frequent use; HSIU, high experience and infrequent use; HSFY, high experience and frequent use.

3.2.1. Experiment 1 Revealed the following Similarities in Most Participants’ Cognitive Memory Regarding Route Map Structure: Users tended to take Taipei Main Station as the fixed cognitive center. Using the reference structure of cognitive maps proposed by Hart (1979), we noted that most users tended to take Taipei Main Station as the fixed center of their spatial cognition memory when reading the current Metro Taipei Route Map. In a structure emphasizing the intersec- tions of the horizontal Blue line and the vertical Red line, users further completed cognitive mapping for the route map by egocentrically referring to their experience regarding transfer ISPRS Int. J. Geo-Inf. 2021, 10, x FOR PEER REVIEW 15 of 27 and terminal stations. Routes in the form of gestalt facilitated cognitive memory. Among the elements for drawing a cognitive route map, in addition to basic colors, transfer stations, and terminal stations,3.2.2. Experiment graphic memory 2: Comparison formed and through Evaluation route shapes of New and Route bifurcations Map Designs of routes on the routeRoberts map helped et al. to [14] enhance refuted users’ the cognitiveview that memory.the conventional octilinear system was the absoluteUsers gold planned standard routes for with route consideration maps. This study of the considered number of future stations plans they for must building pass, andnew the metro transfers lines and required. proposedBased three on route the map destination, designs thethatparticipants employ distinct made compositions. plans that avoidedThe horizontal detours; layout they typically was used planned to ensure their th routesat new from routes near could to far be or fromincorporated far to near in thethe startingfuture; pointits length before was considering set as 95.3 the cm number and its ofwidth transfers as 65 tocm, modify and the the maps route were choice. made Even to thoughscale. To route ensure maps that are route not to composition scale, map readers was not still affected make plansby other according variables, to the all locationsthree de- of stations on a route map (Figure7). sign proposals included time annotation.

FigureFigure 7. 7.Considering Considering the the number number of of transfers transfers to to avoid avoid detours. detours.

Route map A (Proposal A): Route map A was based on a hybrid system. It was an integration of the conventional octilinear and the curve drawing approaches; the Circular line (indicated in yellow) served as the main connecting framework for all the routes. Tai- pei Main Station was the central point of the drawing, and the Circular line was in a per- fect circle. The form of the original route map was preserved in the layouts of other routes, and the distance between two transfer stations were evenly spaced (Figure 8).

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The usability of the current octilinear route map was rated as D. The UMUX evalu- ation score references a formula proposed by Berkman and Karahoca (2016) and converts the score into one similar to the System Usability Scale score for verification. The study revealed that most users rated the usability of the current route map as low, with a score of 69.7, indicating that they were barely satisfied with this route map and thought that space remained for improvement. Users held a positive and supportive attitude toward integrating travel time infor- mation. According to the interview questionnaire results, 78.1% of the participants agreed with the notion of integrating travel time information. The participants stated that they required such time information when using a route map and believed that annotating travel time information would have a positive effect on route planning. Although studies indicate that the temporal distance is not the best way of perfor- mance [21], it is necessary to add time to the map according to users’ opinions. In certain situations, such as when people want to go to another spot before they catch a plane, a time-marked map may help them keep track of their time. People who commute every day may have less need for a time-marked map. We posit that route maps composed of curves may enhance the outcomes of users’ cognitive memory while also increasing the possibility of graphic memory use. The cognitive memory–related performance of CRs and SRs in the drawing approach indicated that the use of curves to replace nodes generated by turns along conventional octilinear routes may reduce the number of nodes and might effectively reduce the load on users’ memory.

3.2.2. Experiment 2: Comparison and Evaluation of New Route Map Designs Roberts et al. [14] refuted the view that the conventional octilinear system was the absolute gold standard for route maps. This study considered future plans for building new metro lines and proposed three route map designs that employ distinct compositions. The horizontal layout was used to ensure that new routes could be incorporated in the future; its length was set as 95.3 cm and its width as 65 cm, and the maps were made to scale. To ensure that route composition was not affected by other variables, all three design proposals included time annotation. Route map A (Proposal A): Route map A was based on a hybrid system. It was an integration of the conventional octilinear and the curve drawing approaches; the Circular line (indicated in yellow) served as the main connecting framework for all the routes. Taipei Main Station was the central point of the drawing, and the Circular line was in a perfect circle. The form of the original route map was preserved in the layouts of other routes, and the distance between two transfer stations were evenly spaced (Figure8). Route map B (Proposal B): For route map B, the conventional octilinear system was employed. The horizontal Blue line and the vertical Red line served as the primary framework for connections, and the stations were distributed along each route as evenly as possible. To equally distribute the stations to the left and right of Taipei Main Station, the composition of the Circular line (indicated in yellow) was revised into a layout whose center was to the middle right (Figure9). Route map C (Proposal C): Route map C employed an all-curve system. This map was generated based on the route layouts of Proposals A and B; the straight lines in the octilinear design were entirely replaced by curves. We used the Bézier curve function in imaging software to transform each route into a smooth state with the fewest anchor points. Despite the use of curves to draw the route map, the relative positions of the stations were preserved (Figure 10). ISPRS Int. J. Geo-Inf. 2021, 10, 569 15 of 24

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ISPRS Int. J. Geo-Inf. 2021, 10, x FOR PEER REVIEW 17 of 27 FigureFigure 8. Route8. Route map map A.A.

Route map B (Proposal B): For route map B, the conventional octilinear system was employed. The horizontal Blue line and the vertical Red line served as the primary frame- work for connections, and the stations were distributed along each route as evenly as pos- sible. To equally distribute the stations to the left and right of Taipei Main Station, the composition of the Circular line (indicated in yellow) was revised into a layout whose center was to the middle right (Figure 9).

FigureFigure 9. 9.Route Route mapmap B. B.

Route map C (Proposal C): Route map C employed an all-curve system. This map was generated based on the route layouts of Proposals A and B; the straight lines in the octilinear design were entirely replaced by curves. We used the Bézier curve function in imaging software to transform each route into a smooth state with the fewest anchor points. Despite the use of curves to draw the route map, the relative positions of the sta- tions were preserved (Figure 10).

ISPRS Int. J. Geo-Inf. 2021, 10, 569 16 of 24 ISPRS Int. J. Geo-Inf. 2021, 10, x FOR PEER REVIEW 18 of 27

Figure 10.10. Route map C.

In ExperimentExperiment 2,2, the the usability usability of of the the three three proposed proposed route route map map designs designs (that (that employ employ the theaforementioned aforementioned three three compositions) compositions) were were compared compared through through usage usage experience, experience, cognitive cog- nitivemapping, mapping, route tasks,route atasks, route a planningroute planning model, model, and an and evaluation an evaluation scale. Thescale. four The route four planningroute planning tasks tasks with designatedwith designated start start and endand end stations stations on differenton different route route maps maps were were as asfollows follows (Table (Table8): 8): Q1: Long-distance routeroute planningplanning with with the the start start and and end end points points diagonally diagonally located located on onthe the drawing. drawing. Q2: Short-distance routeroute planningplanning with with the the start start and and end end points points diagonally diagonally located located on the drawing. on the drawing. Q3: Route planning where the distance between the start and end points was the Q3: Route planning where the distance between the start and end points was the longest. longest. Q4: Route planning where the distance between the start and end points was short Q4: Route planning where the distance between the start and end points was short and the end station was located on the Circular line. and the end station was located on the Circular line.

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Table 8. Four route planning tasks with designated start and end stations on different route maps. Table 8. Four route planning tasks with designated start and end stations on different route maps. TableTable 8. Four 8. Four route route planning planning tasks tasks with with designated designated start start and and end end stations stations on on different different route route maps. maps.

Q1. Q1.Q1

Q2 Q2

Q3 Q3 Q3

Q4Q4 Q4

4. Discussion4. Discussion 4. Discussion 4. DiscussionAlthoughAlthough the the results results of ofthe the cognitive cognitive mapping–based mapping–based route route map map were were affected affected by by Although the results of the cognitive mapping–based route map were affected by users’users’Although usage usage experience the experience results of of the the metro, metro,cognitive experi experience mapping–basedence of ofusing using Taipei’s route Taipei’s mapmetro metro were system system affected did did not by not resultusers’result inusage insignificant significant experience differences differences of the metro,in inthe the time experi time requiredence required of forusing for planning planning Taipei’s route routemetro maps. maps. system did not result in significant differences in the time required for planning route maps. resultWe inWe comparedsignificant compared the differences the participants’ participants’ in the performance time performance required during duringfor planning each each task’s task’s route cognitive cognitive maps. mapping mapping in in We compared the participants’ performance during each task’s cognitive mapping± in termstermsWe of ofcomparederrors errors in intransfer the transfer participants’ station, station, node, performance node, and and angle. angle. during The The findings each findings task’s revealed revealed cognitive an an error mapping error of of ±0.5 in0.5 transfertermstransfer of stationerrors station inwhen transfer when the the station,hybrid hybrid system–bnode, system–based andased angle. Proposal ProposalThe findings A Awas was revealed used, used, which an which error was was of more ±0.5 more transfer station when the hybrid system–based Proposal A was used, which was more favorabletransferfavorable station than than whenwhen when Proposalthe Proposal hybrid B or Bsystem–b orProposal Proposalased C C(eachProposal (each with with A an was an error errorused, of ofalmostwhich almost was1 transfer 1 transfermore favorablestation) than was used.when Proposal Proposal A B aided or Proposal users’ memorization C (each with ofan transfer error of stations almost along1 transfer routes. station)favorable was than used. when Proposal Proposal A aided B or users’Proposal me morizationC (each with of transferan error stations of almost along 1 transfer routes. station)However, was nodeused. errorsProposal differed A aided considerably users’ me betweenmorization the of proposed transfer maps.stations More along node routes. errors However,station) was node used. errors Proposal differed A aided considerably users’ me betweenmorization the of proposed transfer stationsmaps. More along node routes. er- However,occurred node in the errors use ofdiffered Proposals considerably A and B, between which employed the proposed the conventionalmaps. More node octilinear er- rorsHowever, occurred node in theerrors use differed of Proposals considerably A and B, betweenwhich employed the proposed the conventional maps. More octilinear node er- rorssystem, occurred with in the the highest use of Proposals number of A errors and B, noted which for employed Proposal B the (± 4.0).conventional By contrast, octilinear Proposal system,rors occurred with thein the highest use of number Proposals of Aerrors and B,no whichted for employed Proposal theB (±4. conventional0). By contrast, octilinear Pro- system,C, which with was the based highest on number the all-curve of errors system, noted resulted for Proposal in the optimal B (±4.0). performance By contrast, in Pro- terms posalsystem, C, withwhich the was highest based number on the all-curve of errors system, noted forresulted Proposal in the B optimal(±4.0). By performance contrast, Pro- in posalof node C, which error was and based angle on error the all-curve between system, the start resulted and end in stationsthe optimal in the performance cognitive map.in termsposal C,of whichnode errorwas based and angle on th eerror all-curve between system, the startresulted and in end the stations optimal in performance the cognitive in termsThe of experiment node error revealed and angle that error the numberbetween ofthe nodes start drawnand end by stations the participants in the cognitive between

ISPRSISPRSISPRS Int. Int. Int.J. J.Geo-Inf. Geo-Inf.J. Geo-Inf. 2021 2021 2021, 10, 10,, x10, xFOR, FORx FOR PEER PEER PEER REVIEW REVIEW REVIEW 2020 of20 of 27 of27 27

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map.map.map. The The The experiment experiment experiment revealed revealed revealed that that that the the the number number number of of nodesof nodes nodes drawn drawn drawn by by bythe the the participants participants participants be- be- be- tweentweentween routes routes routes affected affected affected the the the locations locations locations of of transferof transfer transfer stations stations stations and and and angles angles angles of of theof the the start start start and and and end end end stationsstationsroutesstations in affectedin theirin their their cognitive cognitive the cognitive locations route route route of maps. transfermaps. maps. For For stationsFor example, example, example, and when when angles when Proposal Proposal ofProposal the start B B was Bwas and was used, used, end used, the stations the the cog- cog- cog- in nitivenitivetheirnitive load load cognitive load generated generated generated route when when maps. when the the Forthe participants participants example,participants whenmemorized memorized memorized Proposal the the Bthe number wasnumber number used, of of nodesof the nodes nodes cognitive increased increased increased load thethegeneratedthe number number number of whenof errorsof errors errors the in participantsin transferin transfer transfer stations stations memorized stations an an dand angles d theangles angles number when when when ofthe the nodes the routes routes routes increased were were were drawn drawn the drawn number (Table (Table (Table of 9).9). errors9). in transfer stations and angles when the routes were drawn (Table9).

TableTableTableTable 9. 9. Experiment 9. 9.ExperimentExperiment Experiment 2 2Route 2Route2 RouteRoute planning planning planningplanning model model modelmodel and and and and cognitive cognitive cognitive cognitive route route route route map map map map comparison. comparison. comparison. comparison. RouteProposal Map RouteProposal Map RouteProposal Map Route Map Proposal ProposalProposalProposal A A A A Proposal ProposalProposal B B B B ProposalProposal ProposalProposal C C C TransferTransferTransfer NodeNodeNodeNode AngleAngleAngle TransferTransferTransfer NodeNodeNodeNode AngleAngleAngleAngle TransferTransferTransfer NodeNodeNodeNode AngleAngleAngle ItemItemItemItem Angle error errorerrorerrorerror ErrorErrorError ** **** ** errorerrorerrorerror errorerrorerrorerror ErrorErrorError ** ** ** ** errorerrorerrorerror errorerrorerrorerror ErrorErrorError ** ** ** ** errorerrorerror OverallOverallOverallOverall ±0.5±±0.50.5±0.5 ±2.5±±2.52.5±2.5 ±5.8°±±5.8°5.8±5.8°◦ ±0.9±±0.90.9±0.9 ±4.0±±4.04.0±4.0 ±6.7°±±6.7°6.7±6.7°◦ ±0.8±±0.80.8±0.8 ±0.9±±0.90.9±0.9 ±5.0°±5.0°±±5.0°5.0 ◦ averageaverageaverageaverage

****p** **p< p

WeWeWeWe used used usedused one-way one-way one-wayone-way analysis analysis analysisanalysis of of ofvarianceof variance variancevariance to to toexamineto examine examineexamine the the thethe performance performance performanceperformance of of the ofof the thethe proposals. proposals. proposals.proposals. WeWeWeWe noted noted notednoted no no no nosignificant significant significantsignificant difference difference differencedifference in in intransferin transfer transfertransfer error error errorerror (F (F (F (2.346)(F (2.346) (2.346)(2.346) = =0.115, ==0.115, 0.115,0.115, p p > p p >0.05)> >0.05) 0.05)0.05) and and andand angle angle angleangle errorerrorerrorerror (F (F (1.065) (F (1.065) (1.065) = =0.359, 0.359,= = 0.359, 0.359, p p> >p0.05) p0.05)> >0.05) 0.05)among among among among the the the proposals. proposals. the proposals. proposals. Ho Ho However,wever,wever, However, the the the results results results the on results on onnode node node on error error nodeerror revealedrevealederrorrevealed revealed a asignificant significanta significant a significant difference difference difference difference (F (F (16.223)(F (16.223) (16.223) (F (16.223)= =0.000, 0.000,= 0.000, p = p< 0.000, Taipei Zoo metro stations InIn TaskIn Task Task Q1, Q1, Q1, the the the greatest greatest greatest difference difference difference between between between Shilin Shilin Shilin and and and Taipei Taipei Taipei Zoo Zoo Zoo metro metro metro stations stations stations was was was was the shape of the Circular line and the shape of Brown line between the Daan and thethethe shape shape shape of of theof the the Circular Circular Circular line line line and and and the the the shap shap shape eof eof Brownof Brown Brown line line line between between between the the the Daan Daan Daan and and and Taipei Taipei Taipei Taipei Zoo metro stations. The results indicated that in Proposal B, 60% of the participants Zoo metro stations. The results indicated that in Proposal B, 60% of the participants used ZoousedZoo metro metro the Circularstations. stations. The line, The results whereas results indicated indicated 40% of that the that in participants in Proposal Proposal B, inB, 60% Proposal60% of of the the participants A participants and 40% ofused used the the Circular line, whereas 40% of the participants in Proposal A and 40% of the partici- theparticipantsthe Circular Circular line, inline,Proposal whereas whereas C40% 40% used of of the this the particip line.particip Theantsants Circular in in Proposal Proposal line A in A and Proposal and 40% 40% of B of the ran the partici- straight partici- pantspantsdownward,pants in in Proposal in Proposal Proposal whereas C C used Cused used the this this Circularthis line. line. line. The The line The Circular Circular in Circular Proposal line line line in Ain Proposal in andProposal Proposal Proposal B B ran Bran ran Cstraight straight required straight downward, downward, downward, a detour to whereaswhereasthewhereas end the the station, the Circular Circular Circular indicating line line line in in Proposalin thatProposal Proposal the drawingA A an A an dand Proposal dProposal style Proposal for C C therequired Crequired required Circular a adetour lineadetour detour in to Proposal to theto the the end end end B sta- gavesta- sta- tion,tion,thetion, indicating participantsindicating indicating that that anthat the impressionthe the drawing drawing drawing ofstyle style fewer style for for detours.forthe the the Circular Circular Circular Similarly, line line line in thein Proposalin Proposal trajectory Proposal B B gave between Bgave gave the the the partici- Daan partici- partici- and pantspantsTaipeipants an an Zooanimpression impression impression metro stations of of fewerof fewer fewer clearly detours. detours. detours. indicated Similarl Similarl Similarl thaty,y, they, zigzagsthe the trajectory trajectory trajectory in Proposal between between between A gaveDaan Daan Daan an and and impression and Taipei Taipei Taipei ZooZooofZoo metro ametro detour.metro stations stations stations Thus, clearly clearly at clearly the indicated Daanindicated indicated metro that that that station zigz zigz zigzagsags inags in Proposalin Proposalin Proposal Proposal A, A onlyA gaveA gave gave half an an ofanimpression impression the impression participants of of aof a a detour.detour.selecteddetour. Thus, Thus, Thus, the at at downward the at the the Daan Daan Daan metro metro zigzag metro station station routes,station in in Proposal whereasin Proposal Proposal A, in A, only ProposalA, only only half half half of C, of the of allthe the participants the participants participants participants selected selected selected chose thethedownwardthe downward downward downward routes zigzag zigzag zigzag in routes, arcs.routes, routes, This whereas whereas whereas finding in in indicatesPropos in Propos Proposalal thatC,al C, allC, all although theall the the participants participants participants most route chose chose mapschose downward downward weredownward based routesroutesonroutes topology, in in arcs.in arcs. arcs. This mostThis This finding finding participants finding indicates indicates indicates attempted that that that although although although to determine most most most route route the route shortestmaps maps maps were were routes were based based based tothe on on terminalontopol- topol- topol- ogy,ogy,stationogy, most most most ratherparticipants participants participants than making attempted attempted attempted a detour. to to determineto determine Moreover,determine the the thisthe shortest shortest shortest indicated routes routes routes why to to theto the the participants’terminal terminal terminal station station station route planning was affected by different representations of the same stations (Figure 11).

ISPRS Int. J. Geo-Inf. 2021, 10, x FOR PEER REVIEW 21 of 27

routes in arcs. This finding indicates that although most route maps were based on topol- ogy, most participants attempted to determine the shortest routes to the terminal station ISPRS Int. J. Geo-Inf. 2021, 10, 569 19 of 24 rather than making a detour. Moreover, this indicated why the participants’ route plan- ning was affected by different representations of the same stations (Figure 11).

FigureFigure 11. 11. ProposalProposal (A,A– CB,) C showed showed participants’ participants route’ route planning planning was was affected affected by by different different representations representations of of the the same same start-endstart-end stations. stations.

In Task Q2, the 30 participants all opted to transfer at St. Ignatius High School metro In Task Ｑ2, the 30 participants all opted to transfer at St. Ignatius High School metro station to progress to the end station, Wugu metro station. In this task, the end station station to progress to the end station, Wugu metro station. In this task, the end station could be directly reached using the Circular line, whereas other routes required at least twocould transfers. be directly The reached results indicatedusing the thatCircular among line, the whereas three proposals, other routes 40%, required 20%, and at 20%least oftwo the transfers. participants The usingresults Proposal indicated A, that B, andamon Cg selected the three the proposals, Circular 40%, line, respectively.20%, and 20% In of Proposalthe participants A, because using of Proposal the clear A, representation B, and C selected of the the Circular Circular line, line, the respectively. usage rate ofIn thisPro- lineposal was A, slightlybecause higherof the clear than representation that in other proposals. of the Circular However, line, the in all usage the proposals,rate of this theline resultswas slightly on route higher planning than similarlythat in other indicated proposal thats. even However, with routes in all requiringthe proposals, two additional the results transfers,on route mostplanning participants similarly still indicated tended to that adopt even a strategy with routes of moving requiring from two the startadditional point totransfers, the end most point participants (i.e., moving still leftward tended to and ad upward).opt a strategy The of Circular moving linefrom led the directly start point to theto the destination; end point however, (i.e., moving it involved leftward circling and up toward). the right The beforeCircular reaching line led the directly end point.to the Thus,destination; it was consideredhowever, it a involved detour. In circling this task, to the avoiding right before a detour reaching was regarded the end point. by most Thus, of participantsit was considered as more a importantdetour. In thanthis task, several avoiding transfers a detour (Figure was 12). regarded by most of par- ticipantsTask as Q3 more was important the most complexthan several among transfers the four(Figure tasks 12). and required at least four transfers. Given the detour involved in the journey, we found that in Proposal A, 40% of the participants opted to wind upward, and 60% of the participants chose to wind downward along the Circular line; half of the participants selected the Purple line, whereas the other half used the Blue line and continued downward before finally winding upward to the end point. In Proposal B, we found that only 10% of the participants employed the upward Circular line, and 90% of the participants selected the downward Circular line; more people opted for the Blue line. In Proposal C, 20% of the participants selected the upward Circular line, and 80% of the participants chose the downward Circular line; more people opted for the Purple line. In all the proposals, most people preferred downward routes in the hope of conforming to the direction of the start point and the end point. Moreover, because of the enhanced representation of the Circular line in Proposal A, the usage rate of the Circular line was slightly higher than that in other proposals. Different representations might affect the route choice even with the same routes (Figure 13).

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ISPRS Int. J. Geo-Inf. 2021, 10, 569 20 of 24 ISPRS Int. J. Geo-Inf. 2021, 10, x FOR PEER REVIEW 22 of 27

Figure 12. Proposal A, B, C showed avoiding a detour was regarded by most participants as more important than several transfers in shorter distance.

Task Q3 was the most complex among the four tasks and required at least four trans- fers. Given the detour involved in the journey, we found that in Proposal A, 40% of the participants opted to wind upward, and 60% of the participants chose to wind downward along the Circular line; half of the participants selected the Purple line, whereas the other half used the Blue line and continued downward before finally winding upward to the end point. In Proposal B, we found that only 10% of the participants employed the upward Circular line, and 90% of the participants selected the downward Circular line; more peo- ple opted for the Blue line. In Proposal C, 20% of the participants selected the upward Circular line, and 80% of the participants chose the downward Circular line; more people opted for the Purple line. In all the proposals, most people preferred downward routes in the hope of conforming to the direction of the start point and the end point. Moreover, because of the enhanced representation of the Circular line in Proposal A, the usage rate

Figure 12. Proposal (A–C) showedof the Circular avoiding line a detour was wasslightly regarded higher by than most that participants in other as proposals. more important Different than severalrepresenta- Figure 12. Proposal A, B, Ctions showed might avoiding affect a thedetour route was choice regarded even by with most theparticipants same routes as more (Figure important 13). than several transferstransfers in in shorter shorter distance. distance.

Task Q3 was the most complex among the four tasks and required at least four trans- fers. Given the detour involved in the journey, we found that in Proposal A, 40% of the participants opted to wind upward, and 60% of the participants chose to wind downward along the Circular line; half of the participants selected the Purple line, whereas the other half used the Blue line and continued downward before finally winding upward to the end point. In Proposal B, we found that only 10% of the participants employed the upward Circular line, and 90% of the participants selected the downward Circular line; more peo- ple opted for the Blue line. In Proposal C, 20% of the participants selected the upward Circular line, and 80% of the participants chose the downward Circular line; more people opted for the Purple line. In all the proposals, most people preferred downward routes in Figure 13. Proposal (A–C)the showed hope different of conforming representations to the mightdirection affect of the the route start choice point even and with the the end same point. routes. Moreover, Figure 13. Proposal A, B, Cbecause showed ofdifferent the enhanced representations representation might affect of the routeCircular choice line even in Proposalwith the same A, the routes. usage rate of theIn Circular Task Q4, line the was terminal slightly station higher was than on that the yellowin other Circular proposals. line, Different and no otherrepresenta- route wastions connectedIn might Task affectQ4, to the this the terminal station.route choice Instation Proposal ev wasen with A,on the ththee Circular yellowsame routes Circular line was(Figure line, represented 13).and no other in a perfect route wascircle, connected which differed to this considerablystation. In Proposal from the A, straightthe Circular lines line of other was represented routes. Overall, in a perfect 90% of circle,the participants which differed selected considerably the Circular from line the as their straight main lines route; of 60%other of routes. the participants Overall, 90% opted of thefor participants upward routes selected with the fewer Circular detours, line whereasas their main 30% route; of the 60% participants of the participants selected routes opted forinvolving upward more routes detours with fewer but one detours, fewer transfer.whereas 30% This of indicated the participants that fewer selected detours routes and transfers were both crucial appeals in route planning, and such results were also clearly demonstrated in Proposals A and Proposal C, with more people opting for upward routes (Figure 14).

Clear differences were observed among the three proposals in terms of choosing the Circular line. Because Proposal A had the most obvious circle, the Circular line in Proposal A was used more frequently in all the tasks, indicating that representations in drawings affect route planning.

Figure 13. Proposal A, B, C showed different representations might affect the route choice even with the same routes.

In Task Q4, the terminal station was on the yellow Circular line, and no other route was connected to this station. In Proposal A, the Circular line was represented in a perfect circle, which differed considerably from the straight lines of other routes. Overall, 90% of the participants selected the Circular line as their main route; 60% of the participants opted for upward routes with fewer detours, whereas 30% of the participants selected routes

ISPRS Int. J. Geo-Inf. 2021, 10, x FOR PEER REVIEW 23 of 27

involving more detours but one fewer transfer. This indicated that fewer detours and transfers were both crucial appeals in route planning, and such results were also clearly ISPRS Int. J. Geo-Inf. 2021, 10, 569 21 of 24 demonstrated in Proposals A and Proposal C, with more people opting for upward routes (Figure 14).

FigureFigure 14.14. ProposalProposal (A,A– B,C )C showed showed fewer fewer detours detours and and transfers transfers were were both both crucial crucial appeals appeals in in route route planning. planning. The route map evaluation and preference ranking conducted after the tasks were Clear differences were observed among the three proposals in terms of choosing the completed revealed that the participants were still more adept at using the route map with Circular line. Because Proposal A had the most obvious circle, the Circular line in Proposal the conventional octilinear composition and were more willing to use it. By comparison, A was used more frequently in all the tasks, indicating that representations in drawings most participants held a conservative attitude regarding the use of the route composition affect route planning. employing the all-curve system in Proposal C. Moreover, as an explanation for their The route map evaluation and preference ranking conducted after the tasks were negative evaluation of the route map, they stated that it clearly did not conform to the completed revealed that the participants were still more adept at using the route map with official conventional style and seemed more suitable for special occasions. Overall, the the conventional octilinear composition and were more willing to use it. By comparison, travel time annotations added in the experiment gained positive feedback from most of most participants held a conservative attitude regarding the use of the route composition the participants. Proposal B included a conventional octilinear route map with which the employing the all-curve system in Proposal C. Moreover, as an explanation for their neg- users were the most familiar. The route map based on the all-curve system in Proposal ative evaluation of the route map, they stated that it clearly did not conform to the official C received an inferior evaluation by the users in terms of usability and participants’ subjectiveconventional preference style and because seemed they more were suitable unfamiliar for special with occasions. it. However, Overall, these the users travel noted time thatannotations the curved added composition in the experiment alleviated thegained trouble positive of an excessivefeedback numberfrom most of turning of the partici- points alongpants. the Proposal metro B lines included when a planning conventional a single octilinear route androute enabled map with them which to concentrate the users were on connectionsthe most familiar. between The metro route linesmap based and stations. on the all-curve Thus, the system participants’ in Proposal performance C received inan theinferior route evaluation tasks was theby the highest users in in Proposal terms of C usability among the and three participants’ route maps. subjective Furthermore, prefer- theence cognitive because mappingthey were results unfamiliar of Proposal with it. C However, suggested these certain users advantages; noted that particularly, the curved thecomposition advantage alleviated of fewer nodethe trouble errors wasof an significant. excessive number Despite theof turning absence points of a significant along the differencemetro lines between when planning the three a route single maps route in and terms enabled of usage them performance, to concentrate Proposal on connections C (using thebetween all-curve metro system–based lines and stations. composition) Thus, resultedthe participants’ in improvements performance in the in users’ the route cognitive tasks memorywas the andhighest was in equally Proposal useful C foramong route the planning three route as the maps. maps usingFurthermore, the octilinear the cognitive system. Proposalmapping A,results based of on Proposal the hybrid C suggested system, obtainedcertain advantages; the highest particularly, score in the the participants’ advantage subjectiveof fewer node evaluation. errors was Because significant. in Proposal Despite A thethe Circularabsence lineof a wassignificant drawn difference with curves, be- ISPRS Int. J. Geo-Inf. 2021, 10, x FORthe tweenPEER conspicuous REVIEW the three route shape maps helped in terms facilitate of usage decision-making, performance, and Proposal the task C (using performance the24 all-curve of 27 was

secondsystem–based only to thatcomposition) in Proposal resulted C (Figure in improv 15). ements in the users’ cognitive memory and was equally useful for route planning as the maps using the octilinear system. Proposal A, based on the hybrid system, obtained the highest score in the participants’ subjective evaluation. Because in ProposalProposal A theA CirculProposalar Bline wasProposal drawn C with curves, the conspicu-

ous100% shape helped facilitate decision-making, and the task performance90% was second only to that in Proposal C (Figure 15). 80% 60% 60% 60% 50% 40%40% 40% 40% 40% 20% 20% 20% 20% 10% 0% Q1 Q2 Q3 Q4

FigureFigure 15. 15.Differences Differences were observed in in term termss of of choosing choosing the the Circular Circular line. line.

Even fully schematized map representations retain topology but scale in someplace changes too much make geography becomes distorted. On the other hand, the semi-sche- matic design merges elements of the schematic map to locally simplify the representation, but retains an overall geographically correct approach. Thus, the semi-schematic design is a compromise between a fully schematic map and truly realistic geographical represen- tation [22]. Previous studies [7,11,12] revealed that concise graphics comprising circular lines as well as vertical and horizontal key routes helped users build their spatial cognition and that route maps should be designed in accordance with local conditions.

5. Conclusions The design process is viewed as a series of stages beginning with problem identifica- tion and ending with implementation. Evaluation, creativity, experimentation, and map aesthetics are part of the design activity. No one best way to a design solution can be predetermined for all maps—only principles and general approaches can guide the car- tographer. The map’s design elements must be arranged into a graphic composition suit- able to the map’s communication purpose. The elements include the map’s title, scale, neat-line, symbols, and other components. Using visualization and experimentation tech- niques, the composition elements are arranged to satisfy the design goals [23]. The route planning tasks in Experiment 1 revealed that the users tended to favor the fewest transfers and the shortest routes. Usage experience did not result in significant dif- ferences in performance in route planning using a route map. Most errors originated in misreading transfer stations, which was associated with whether routes in a route map involved wide-angled turning points. The users tended to take Taipei Main Station as the center of the current route map, and their memory of routes progressively declined with greater distance from the main transit hub. The particular graphical representation in the current route map, such as a square-shaped route, formed “memorization graphics” in the users’ cognitive memory, which facilitated identification during use. However, in drawing routes with weaker representation in cognitive memory, most participants opted to use the curved composition to represent connections between routes to grasp the rela- tive positions among stations. Thus, in the new design proposals, in addition to address- ing the problems of the current route map determined in Experiment 1, future routes and travel time information were integrated. Using three types of route designs, namely the hybrid system, the conventional octilinear design, and the all-curve system, the effects of route composition on usage behavior and cognitive memory were investigated. Experiment 2 revealed differences in evaluation and preference regarding the three route maps; however, the difference in terms of performance in the overall route planning between the route maps was slight. The two route maps that employed the curved com- position resulted in obvious advantages in route planning for specific routes. Subsequent comparison of transfer stations, nodes between routes, and angle between the start and

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Even fully schematized map representations retain topology but scale in someplace changes too much make geography becomes distorted. On the other hand, the semi- schematic design merges elements of the schematic map to locally simplify the represen- tation, but retains an overall geographically correct approach. Thus, the semi-schematic design is a compromise between a fully schematic map and truly realistic geographical representation [22]. Previous studies [7,11,12] revealed that concise graphics comprising circular lines as well as vertical and horizontal key routes helped users build their spatial cognition and that route maps should be designed in accordance with local conditions.

5. Conclusions The design process is viewed as a series of stages beginning with problem identifica- tion and ending with implementation. Evaluation, creativity, experimentation, and map aesthetics are part of the design activity. No one best way to a design solution can be predetermined for all maps—only principles and general approaches can guide the cartog- rapher. The map’s design elements must be arranged into a graphic composition suitable to the map’s communication purpose. The elements include the map’s title, scale, neat-line, symbols, and other components. Using visualization and experimentation techniques, the composition elements are arranged to satisfy the design goals [23]. The route planning tasks in Experiment 1 revealed that the users tended to favor the fewest transfers and the shortest routes. Usage experience did not result in significant differences in performance in route planning using a route map. Most errors originated in misreading transfer stations, which was associated with whether routes in a route map involved wide-angled turning points. The users tended to take Taipei Main Station as the center of the current route map, and their memory of routes progressively declined with greater distance from the main transit hub. The particular graphical representation in the current route map, such as a square-shaped route, formed “memorization graphics” in the users’ cognitive memory, which facilitated identification during use. However, in drawing routes with weaker representation in cognitive memory, most participants opted to use the curved composition to represent connections between routes to grasp the relative positions among stations. Thus, in the new design proposals, in addition to addressing the problems of the current route map determined in Experiment 1, future routes and travel time information were integrated. Using three types of route designs, namely the hybrid system, the conventional octilinear design, and the all-curve system, the effects of route composition on usage behavior and cognitive memory were investigated. Experiment 2 revealed differences in evaluation and preference regarding the three route maps; however, the difference in terms of performance in the overall route plan- ning between the route maps was slight. The two route maps that employed the curved composition resulted in obvious advantages in route planning for specific routes. Subse- quent comparison of transfer stations, nodes between routes, and angle between the start and end stations in the cognitive route map indicated that the maps using curved routes significantly enhanced cognitive memory in comparison with the conventional octilinear route map. Users’ cognitive errors could be reduced by lowering the number of nodes between routes, which was also advantageous for grasping the transfers and relative location of the route taken. As we knew, the more clearly we relate schematic maps to the critical elements of the environment represented, the more easily users can find an orientation solution [24]. Brewer [25] indicated that the internal elements of the map should maintain a linear balance. The positioning of the top of these elements should fall along a common linear position. The same can be true of elements that can align vertically. This alignment brings an orderly appearance to the map and thus produces a harmonic balance to the layout design. These alignments can be achieved in mapping software using guidelines and background grids. Compared with the current route map, an all-curve map would probably require a considerable amount of time for the public’s adaptation. We recommend first converting some routes into distinct memorization graphics using the route composition ISPRS Int. J. Geo-Inf. 2021, 10, 569 23 of 24

based on the hybrid system to enhance user performance in route planning and cognitive memory. The provision of travel time information on route maps may enhance users’ decision-making efficiency when using the route map. Based on the experimental results, the following suggestions regarding route map design are provided: Avoiding excessive nodes on the routes. We found that users’ cognitive load increased in the case of excessive turning points along the routes when using route maps based on the conventional octilinear system and the all-curve system, which easily caused memory errors. For large-scale routes, the turning points of the original routes may be replaced with route sections of curved composition to lower the number of nodes on the routes. 1. Avoiding unsuitable turning points on routes. This study revealed that in determin- ing the necessity of transferring along a route, most users used route color, route turning points, and transfer station signs to confirm transfer stations along the route. Inappropriate route turning points may lead to users misreading or overlooking trans- fer stations. Thus, in future route map designs, route representations with sudden turning points should be avoided as much as possible. 2. Integrating clear visual centers and graphics. The experiment using the route map based on the hybrid system revealed that visual representations that include obvious central stations or conspicuously shaped routes enabled users to plan routes rapidly, assisted in their decision-making, and enhanced their memory. 3. Enlarging the areas with high transfer station density. As the size of routes grows, route map information becomes increasingly complex. This complexity may be mitigated by enlarging transfer station areas along high-volume routes and as much as possible proportional to the travel time shown, reducing information congestion and facilitating route planning. 4. Integrating travel time information. The layout of routes on a route map, which are not to scale, often results in a distorted line length ratio. Thus, misreading caused by route length may be reduced by integrating travel time annotations, thus providing users a basis for estimating travel time and increasing the efficiency of decision-making in route planning. In this evidence-based study, we first observed the route map of Taipei’s metro system and investigated proposals for new designs to identify critical factors affecting users’ cognition. Then we observed users’ cognitive memory and behavior regarding route maps and used diverse design approaches to examine the relationships between route map composition and cognitive mapping. Cartographic communication can only be successful if sound map design principles are fully understood and used properly [26]. A map’s design should be judged only regarding the map’s purpose and intended audience [27]. With limited resources, results of this study need to be repeated in the future with more participants to be verified. We expect our research findings will become effective references and suggestions for future route map design.

Author Contributions: Meng-Cong Zheng contributed to the original ideas of the paper and de- signed the experiments. Yao-Wei Liu performed the experiments and analyzed the experimental data un-der the supervision of Meng-Cong Zheng. Yao-Wei Liu wrote the first draft of the manuscript; Meng-Cong Zheng revised and edited it. All authors have read and agreed to the published version of the manuscript. Funding: This research received no external funding. Data Availability Statement: Due to confidentiality agreements, supporting data can only be made available to bona fide researchers subject to a non-disclosure agreement. Details of the data and how to request access are available from Meng-Cong Zheng ([email protected]) at National Taipei University of Technology. Acknowledgments: Special thanks for all participants and Taipei Metro who generously shared their time and experience, for the purposes of this study sections. Conflicts of Interest: The authors declare no conflict of interest. ISPRS Int. J. Geo-Inf. 2021, 10, 569 24 of 24

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