Open Geosci. 2019; 11:140–151 Research Article Open Access Mohammed Zia*, Ziyadin Cakir, and Dursun Zafer Seker Turkey OpenStreetMap Dataset - Spatial Analysis of Development and Growth Proxies https://doi.org/10.1515/geo-2019-0012 Received February 1, 2018; accepted April 16, 2018 1 Introduction Abstract: Number of studies covering major data aspects With the ease of online-data generation and dissemination of OpenStreetMap (OSM) for developed cities and coun- by the advent of Web2.0 technology the narrowly-targeted tries are available in scientific literature. However, this goods and services are getting as economically attractive is not the case for developing ones mainly because of and lucrative as mainstream fare [1, 2]. For example, we low data availability in OSM. This study presents a time- now have Whatsapp, Skype, Viber etc. in Telecommunica- series spatial analysis of Turkey OSM dataset, a devel- tion sector, which was predominantly governed by Tele- oping country, between the year 2007 and 2015 to un- com industries for decades. Wikipedia holds a huge pile derstand how the dataset has developed with time and of online free-content and competes with other propri- space. Five different socio-economic factors of the region etary data sources like Encyclopedia Britannica. Recent are tested to find their relationship, if any, with dataset free publication of classified information by WikiLeaks growth. An east-west spatial trend in data density is ob- and OpenLeaks has challenged governments and other na- served within the country. Population Density and Liter- tional intelligence agencies, who were regulating confi- acy Level of the region are found be the factors control- dential information of citizens so far [3]. ling it. It has also been observed that the street network of Similarly, the Volunteered Geographic Informations the region has followed the Exploration and Densification (VGI) [4, 5] or Crowdsourcing Geographic Data [6, 7] have evolutionary model. High participation inequality is found evolved to hold and control the geographic data which within the OSM mappers, with only 5 of them responsi- was complied and retained by National Mapping Agen- ble for the country’s 50% geo-data upload. Furthermore, cies and other private cartographic companies in the past it is found that these mappers use other Volunteered Geo- [8]. The reason for their sudden success is the ease of graphic Information (VGI) and government open-dataset geo-data generation and circulation where human-beings to feed into OSM. This study is believed to bring some act as a sensor [9]. This contemporary approach has al- high level insights of OSM for a developing country which lowed even naive cartographers/citizens with limited or would be useful for geographers, open-data policy mak- no mapping experience to collect, map and upload geo- ers, VGI projects planners and data-curators to structure data of any region. One famous VGI project is called Open- and deploy similar future projects. StreetMap (OSM) which was started in the year 2004 with the objective to create a free and editable street map of the Keywords: OpenStreetMap, spatial development, socio- world [10]. Although there are many other VGI projects like economic factors, Exploration and Densification Wikimapia, Wikiloc, Foursquare and Google Map Maker, the hype in populatiry of OSM is because of flexible li- censing, active community and advanced symantics. This classic example has recently gained immense popularity because of its big volume data, heterogeneity, abundance *Corresponding Author: Mohammed Zia: GIScience Re- and free data access [11, 12], and therefore has attracted search Group, Institute of Geography, Heidelberg University, researchers from ranging domains [13]. Heidelberg, Germany, E-mail: [email protected]; https://www.linkedin.com/in/zia33 By the end of 2015, OSM dataset has had an enormous Ziyadin Cakir: National Innovation and Research Center for Geo- amount of tagged geo-data in the form of approximately graphical Information Technologies, Turkey 5 billion GPS points, 3 billion nodes, 3 billion ways and and Department of Geology, Faculty of Mines, Istanbul Technical 4 million relations, which were contributed by around 2.5 University, Turkey million registered users worldwide [14]. One of the many Dursun Zafer Seker: Geomatics Engineering Department, Faculty possible reasons for this popularity hype was the partial of Civil Engineering, Istanbul Technical University, Turkey Open Access. © 2019 Mohammed Zia et al., published by De Gruyter. This work is licensed under the Creative Commons Attri- bution alone 4.0 License. Turkey OpenStreetMap Dataset Ë 141 pulling out of Google-Maps APIs in 2012 from their public ural calamities like the infamous Haiti earthquake of 2010 domain [15]. This encouraged services like Apple iPhoto, [42]. [9, 43, 44] have argued the personal satisfaction and FourSquare, Craiglist, Flickr [16], etc. to use OSM. This community serving as two key motivating factors behind massive dataset has brought forth possibilities to investi- any crowd sourcing activity. gate data aspects such as data accuracy, data exhaustive- The aim of this study is to understand the time-series ness, time-series data evolution, motivation behind map- spatial evolutionary pattern of Turkey OSM dataset be- ping, relationship with other VGI projects, etc. [17]. tween the year 2007 and 2015 in order to help researchers, Dataset accuracy of OSM at regional and global scale developers and policy makers to better structure current has already been studied by researchers from different as- and future VGI projects, to identify best policies for open- pects; for examples, by comparing it with government and data license, to predict data growth and quality of cer- other dataset [18, 19], by using proxy approaches like Li- tain regions and more. Many researchers in the past have nus Law [20] or contributors count [21–23], by developing done similar studies for developed countries and cities. intrinsic quality assessment parameters and tools [24–26], For example, [30] have reported how the online map- by reviewing OSM changeset dump file [27] etc. OSM par- ping was active in the year 2009 in Germany and tried to ticipation inquality is extensively studied by researchers compare it with TeleAtlas MultiNet dataset, [45] have per- as a proxy for data quality check-up [data_quality / formed an interregional comparisons of European regions, 1/participation_inequality] [13, 22, 23]. However, this [46] have analysed three urban areas in Ireland to under- proxy was opposed by [28] by negating the idea of count- stand the time-series street network evolutionary pattern ing the number of contributors for quality assurance. [25] in OSM and [47] and [48] have reported the densification and [26] have tried to use the intrinsic parameters of OSM and evolutionary model for Irish and Chinese street net- for data scrutiny and health, thus adding additional qual- work dataset, respectively. Additionally, the effect of dif- ity assurance mechanisms. It is reported that the early ferent socio-economic factors of the region, i.e. Literacy adopters of OSM project, like Germany and UK, contain Level (number of graduate students), Population Density, dataset of high quality standards. Few regions of Germany Tourism Activity, Internet Usage [21] and Human Develop- contain dataset even more accurate and exhaustive than ment Index (HDI), are tested on this growth. A general Google Maps. However, this quality standard is limited and commentary on the state of the OSM dataset quality and many developing and under-developed nations still lag mappers involvement of the country is provided in the end. mapping of elementary features. To the best of authors’ knowledge, this kind of high resolu- Detailed analysis on the coverage and quality estima- tion (at provincial level) OSM time-series statistical analy- tion of OSM dataset has always been an issue because sis of a developing country is first of its kind. We hope that of strict licensing policy, limited usage/availability, high this study will bring forth patterns, trend, proxy parame- pricing etc. of government and other proprietary dataset ters and future research paradigms that are necessary to that act as a reference dataset. For example, [29], [18], restructure existing and future VGI projects. [19] and [30] have reported this limitation for Portugal, London, Kenya and Germany, respectively. Nonetheless, some notable scientific studies are available online that 1.1 OSM in Turkey acted as a motivation for this study. [31] have studied the dataset of Germany using some proprietary dataset, [32] No key study of Turkey OSM dataset regarding (a) spatial have compared the bicycle trail and lane dataset of OSM evolution with time, (b) different socio-economic factors with data from local planning agencies for USA, [16] have governing it, (c) mappers involvement within the coun- mapped the street network dataset of USA by comparing try, (d) dataset quality is available online. Current study, it with TIGER/Line dataset etc. Few OSM use-case scenar- therefore, becomes essential to answer key elements of ios include measuring the street network evolution as a the ecosystem on spatial and temporal ground as has al- proxy for urban sprawl [34], developing Location-Based ready been done by other researchers for developing na- and Emergency Medical Services [35–37], generating in- tions but at a much coarser level. For example, [13], [19] teractive 3D City Models using Shuttle Radar Topography and [48] have done similar spatial and temporal analysis Mission height data [38], extracting Image-based road net- for street networks of Beijing, Kenya and China, respec- work [39] and multilane roads data [40], calculating short- tively. Turkey OSM provides a rich dataset with nearly 17 est routes within urban cities [33], validating/reforming million points, 1.3 million edges and 0.4 million polygons existing Land Use/Land Cover (LULC) data like Global [49]. In this study, the term edge is used for any line and Land Cover Maps [41] etc.