Freight on Transit Delphi Study
by
Keith Cochrane
A thesis submitted in conformity with the requirements for the degree of Master of Applied Science Department of Civil Engineering University of Toronto
© Copyright by Keith Cochrane 2012
Freight on Transit Delphi Study
Keith Cochrane
Master of Applied Science
Department of Civil Engineering University of Toronto
2012 Abstract
The Freight on Transit Delphi Study was conducted to explore the concept of freight on transit – using public transit vehicles and infrastructure for transporting things other than people. Three rounds of web based surveys were conducted with a panel of 34 transportation experts to explore the main issues related to freight and transit integration and to build and evaluate potential freight on transit operations. Survey results were consistent with previous investigations and suggest that organizational disputes are a larger barrier to implementation than technical challenges.
Traditional Delphi questions were used to determine the most important positive impacts, negative impacts, and challenges of moving freight on transit networks while survey responses combined with scenario building techniques were used to build and evaluate five potential freight on transit operating strategies using public transit networks in the GTHA.
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Acknowledgments
First and foremost I would like to thank my supervisors Matthew Roorda and Amer Shalaby for the advice, guidance, and expertise they provided throughout this research process.
I would also like to thank Metrolinx for supporting this project, in particular Anthony Caruso and Maureen McLeod.
As well, I want to thank the 34 experts that participated in the Delphi Study as well as students and other Metrolinx staff who participated in survey testing rounds.
Finally I would like to thank my family and Miriam for their encouragement and patience.
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Table of Contents
Acknowledgments ...... iii
Table of Contents ...... iv
List of Tables ...... vii
List of Figures ...... ix
List of Appendices ...... xi
List of Acronyms/Variables ...... xii
Chapter 1: Introduction and Background ...... 1
1.1 Urban Goods Movement ...... 1
1.2 Public Transit Operations ...... 2
1.3 Research Questions and Objectives ...... 3
1.4 Thesis Structure ...... 5
Chapter 2: Literature Review ...... 6
2.1 Existing FOT Operations ...... 6
2.1.1 FOT-EX: Freight on Existing Public Transit Trips ...... 6
2.1.2 FOT-NEW: New Freight Trips on Existing Public Transit Infrastructure ...... 8
2.1.3 Transit on Freight ...... 11
2.2 Proposed FOT Operations ...... 13
2.3 Summary of Findings ...... 13
2.4 The Delphi Method ...... 14
2.4.1 The Delphi Method for Transportation and Logistics Planning ...... 16
Chapter 3: Research Methods ...... 18
3.1 The Delphi Method ...... 18
3.1.1 Justification ...... 19
3.1.2 Strength and Weaknesses ...... 20 iv
3.2 Typical Delphi Procedure ...... 23
3.2.1 Number of Delphi Rounds ...... 24
3.2.2 Defining Expertise and Selecting the Number of Participants ...... 24
3.2.3 Survey Structure and Evaluation ...... 26
3.2.4 Statistical Methods ...... 28
3.2.5 Feedback Provided to Delphi Experts ...... 32
3.3 FOT Delphi Procedure ...... 33
3.3.1 Objective 1: Explore main issues of FOT operations ...... 33
3.3.2 Objective 2: Build and Evaluate FOT Operating Strategies for the GTHA ...... 36
Chapter 4: Survey Process ...... 40
4.1 Web Based Survey ...... 40
4.2 Recruiting Experts and Minimizing Non-Response and Attrition ...... 41
4.3 Survey Design ...... 42
4.4 Survey 1 ...... 43
4.4.1 Layout ...... 44
4.4.2 Pretesting ...... 48
4.4.3 Delivery ...... 51
4.5 Survey 2 ...... 52
4.5.1 Layout ...... 57
4.5.2 Pretesting ...... 60
4.5.3 Delivery ...... 63
4.6 Survey 3 ...... 64
4.6.1 Layout ...... 66
4.6.2 Pretesting ...... 69
4.6.3 Delivery ...... 71
Chapter 5: Results and Analysis ...... 72 v
5.1 Response and Retention Rates ...... 72
5.2 Demographics of Expert Panel ...... 73
5.3 FOT Issues ...... 76
5.3.1 FOT Positive Impacts ...... 77
5.3.2 FOT Negative Impacts ...... 81
5.3.3 FOT Challenges ...... 86
5.3.4 Summary of Findings ...... 91
5.4 FOT Strategy Building and Evaluation ...... 92
5.4.1 Strategy Building ...... 92
5.4.2 Proposed FOT Strategies ...... 98
5.4.3 Final Strategy Evaluations ...... 107
5.4.4 Summary of Findings ...... 108
Chapter 6: Conclusion ...... 110
6.1 The Delphi Method ...... 110
6.2 Freight on Transit ...... 111
6.3 Future Work ...... 112
References ...... 114
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List of Tables
Table 2-1 Summary of Existing FOT Operations ...... 12
Table 3-1 Interpretation of Kendall's W ...... 29
Table 3-2 Derivation of R ...... 31
Table 4-1 Survey 1 Drafts and Final Version ...... 48
Table 4-2 Survey 1 Response Frequencies ...... 54
Table 4-3 Survey 2 Drafts and Final Version ...... 61
Table 4-4 FOT Performance Criteria and Links to Survey 2 Items ...... 67
Table 5-1 Retention Rates by Round ...... 72
Table 5-2 Round 1 FOT Positive Impacts ...... 77
Table 5-3 Round 2 FOT Positive Impacts Statistical Summary ...... 78
Table 5-4 Round 2 FOT Positive Impacts Response Frequencies ...... 80
Table 5-5 Round 3 FOT Positive Impacts Statistical Summary ...... 81
Table 5-6 FOT Positive Impacts Changes Between Rounds ...... 81
Table 5-7 Round 1 FOT Negative Impacts ...... 82
Table 5-8 Round 2 FOT Negative Impacts Statistical Summary ...... 83
Table 5-9 Round 2 FOT Negative Impacts Response Frequencies ...... 84
Table 5-10 Round 3 FOT Negative Impacts Statistical Summary ...... 85
Table 5-11 FOT Negative Impacts Changes Between Rounds ...... 85
Table 5-12 Round 1 FOT Challenges ...... 87
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Table 5-13 Round 2 FOT Challenges Statistical Summary ...... 88
Table 5-14 Round 2 FOT Challenges Response Frequencies ...... 89
Table 5-15 Round 3 FOT Challenges Statistical Summary ...... 90
Table 5-16 FOT Challenges Changes Between Rounds ...... 90
Table 5-17 Round 1 FOT Goods Types ...... 93
Table 5-18 Round 2 FOT Goods Types Statistical Summary ...... 93
Table 5-19 Survey 2 FOT Design Decisions - Feasibility ...... 95
Table 5-20 Survey 2 FOT Design Decisions - Desirability ...... 95
Table 5-21 FOT Operating Strategies and Links to Round 2 Inputs ...... 97
Table 5-22 Summary of Proposed FOT Operations ...... 99
Table 5-23 FOT Strategies Final Rankings ...... 108
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List of Figures
Figure 3-1 Research Questions ...... 18
Figure 3-2 Key Delphi Features ...... 19
Figure 3-3 Criteria Motivating a Delphi Study ...... 19
Figure 3-4 Typical Objectives of a Policy Delphi ...... 20
Figure 3-5 Delphi Strengths and Weaknesses ...... 22
Figure 3-6 Typical Delphi Process ...... 23
Figure 3-7 Defining and Motivating Delphi Experts ...... 25
Figure 3-8 KRNW for FOT Delphi Expert Recruitment ...... 26
Figure 3-9 Sorted Rankings for Calculation of W ...... 30
Figure 3-10 Statistics Used ...... 32
Figure 3-11 FOT Delphi Survey Process ...... 34
Figure 3-12 Likert Scales for Questions 2.1-2.3 ...... 35
Figure 3-13 Feasibility and Desirability Scale ...... 37
Figure 3-14 FOT Design Decisions: Questions 2.5-2.9 ...... 38
Figure 4-1 FOT Delphi Survey 1 ...... 44
Figure 4-2 Timing of Survey 1 Responses ...... 52
Figure 4-3 FOT Delphi Survey 2 ...... 53
Figure 4-4 Question 2.1 - FOT Positive Impacts ...... 55
Figure 4-5 Question 2.2 - FOT Negative Impacts ...... 55
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Figure 4-6 Question 2.3 - FOT Challenges ...... 56
Figure 4-7 Question 2.4 - FOT Goods ...... 56
Figure 4-8 Likert Scale Modifications ...... 63
Figure 4-9 Timing of Survey 2 Responses ...... 64
Figure 4-10 FOT Delphi Survey 3 ...... 65
Figure 4-11 Timing of Survey 3 Responses ...... 71
Figure 5-1 Delphi Participants by Highest Degree Earned ...... 73
Figure 5-2 Delphi Participants by Area of Expertise ...... 74
Figure 5-3 Delphi Participants by Workplace Sector ...... 75
Figure 5-4 Delphi Participants by Years of Work Experience ...... 76
Figure 5-5 The Greater Toronto and Hamilton Area ...... 98
Figure 5-6 Air Rail Mail ...... 100
Figure 5-7 Paper Train ...... 101
Figure 5-8 Mall Haul ...... 103
Figure 5-9 Liquor Line ...... 104
Figure 5-10 Commuter Rail Mail ...... 106
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List of Appendices
Appendix A: Survey 1 ...... 122
Appendix B: Survey 2 ...... 134
Appendix C: Survey 3 ...... 146
Appendix D: Invitation Email ...... 163
Appendix E: FOT Delphi Video Script ...... 164
Appendix F: Recruitment Postcard ...... 167
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List of Acronyms/Variables
3PL – Third Party Logistics
ARL – Air Rail Link
CBD – Central Business District
FOT – Freight on Transit
FOT-EX – Freight on Existing Public Transit Trips
FOT-NEW – New Freight Trips on Existing Public Transit Infrastructure
GTHA – Greater Toronto and Hamilton Area
IQR – Interquartile Range
KRNW – Knowledge Resource Nomination Worksheet
LOS – Level of Service
PPP – Public Private Partnership
RAND – Research and Development Corporation
SD – Standard Deviation
TTC – Toronto Transit Commission
W – Kendall’s Coefficient of Concordance
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Chapter 1: Introduction and Background
Urban goods movement is of considerable interest to transportation planners due to its central role in the urban economy as well as the detrimental effects of truck movements on the transportation network including congestion, emissions, noise pollution, and pavement damage. Meanwhile, public transit agencies possess assets such as stations, transit vehicles and rail networks that sit underutilized outside of peak periods. With space in urban areas at such a premium, it might be worth exploring opportunities to use public transit infrastructure for goods movement as a means of minimizing the impact of freight operations and increasing the efficiency of existing infrastructure. This study begins with a description of both freight and transit operations and some of the factors promoting their integration.
1.1 Urban Goods Movement
Urban goods movement, or freight transportation, is defined as any commercial or service trip on the transportation network with its origin and/or destination inside an urban area (Metrolinx 2011). This includes the transportation of construction materials, courier movements, garbage collection, etc. Goods movement trips are usually split among the four major modes: air, rail, road, and marine, but also include pipeline transport and active modes like walking and cycling. Marine and rail are common modes for long haul trips but trucks dominate “last mile” deliveries to final destinations, especially in urban areas. It is estimated that anywhere from 70- 90% of all freight movements in urban areas in Europe and North America are done by trucks (Larsson and Gotland 2009; Metrolinx 2010). Trucks are the vehicle of choice for “last mile” trips because they are flexible, cheap, and can make use of existing road infrastructure.
Operating trucks in urban areas comes with many challenges including inefficiencies, accessibility issues, insufficient infrastructure, and a lack of consideration during the transportation planning process (OECD 2003). Trucks usually operate at low profit margins and due to a scattered customer base are forced to move empty for a large portion of the time. For even the most efficient companies, 20% of truck miles are driven by empty trucks with the percentage as high as 50% for inefficient firms (Rowinski, Ya and Boile 2001). The lack of consideration for goods movement in land use and transportation planning leads to further
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difficulties for trucks in urban areas including increased travel time and fuel consumption due to a lack of parking, having to park far away from final destinations, and the high costs of parking fines which can be a multimillion dollar expense for lager companies (Haider 2009).
Trucks are also extremely harmful to both the environment and the transportation network. The Texas Transportation Institute (TTI) 2011 Mobility Report estimates that though trucks only account for about 6% of miles travelled in urban areas, they are responsible for nearly 26% of congestion due to their size and driving patterns like wide turning movements and curbside loading and unloading (Schrank, Lomax and Eisele 2011). Congestion leads to huge costs with the largest components being time delays, fuel costs and costs related to greenhouse gas (GHG) emissions. Congestion in the Greater Toronto and Hamilton Area (GTHA) is estimated to cost the regional economy roughly $6 billion every year (Toronto Board of Trade 2011). TTI reports even larger annual congestion costs from $8-$11 billion for the three largest American cities (New York, Chicago, Los Angeles), and annual congestion delays of up to 50 hours per person living in these areas (Metrolinx and HDR 2008; Schrank et al. 2011). Trucks have negative impacts in other areas as well including safety, as nearly 20% of road fatalities are due to heavy truck collisions and pavement damage, as a single loaded 102’ truck wears out roadways as much as 10,000 passenger cars (Bjorner 1999; Transport Canada 2010).
1.2 Public Transit Operations
Public transit, or public transportation, includes a variety of shared passenger transportation services available for use by the general public, including buses, streetcars, subways, ferries and their variations. The main benefits of public transit include congestion reduction, energy and GHG reductions, lower road maintenance costs, increased road safety, and increased social mobility (Litman 2012). The main costs include infrastructure and capital costs as well as operating costs which are primarily made up of labour, fuel, and vehicle and network maintenance costs. Public transit agencies generate revenue mostly through ticket sales, advertisements, and government subsidies. Governments justify subsidizing transit to mobilize citizens who are unable to afford automobiles; to reduce congestion, emissions, and road maintenance costs; and to renew urban areas and promote economic growth (Cox and O'Toole 2004).
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Operating an efficient public transit system is extremely challenging due to high operating costs, fluctuating ridership and high passenger demands. Agencies struggle to cover operating costs through fare revenue with fare box recovery ratios, the ratio of revenue generated by fares to operating costs, in large North American cities ranging anywhere from 36% for the New York City Metro Transit Authority (MTA) to 83.6% for GO Transit in the GTHA (Taylor and Lindquist 2009). The remainder of costs is covered through advertising and government subsidies, but if subsidies are not sufficient, agencies must reduce trip frequencies or eliminate services altogether. Travel patterns make it difficult to keep operations financially viable as a high proportion of transit riders are commuters producing heavy one way passenger flows between suburbs and downtown areas in the morning and afternoon peaks. The high levels of ridership are not sustained outside of these periods meaning vehicles run with low levels of ridership while others will travel empty (deadhead) to storage yards or facilities and sit idle between peak periods (Kim 2003). These travel patterns also result in fluctuating labour requirements with labour costs making up the largest proportion of operating costs. Unions and labour contracts often limit or prohibit split shifts and part time labour resulting in operations that underutilize human capital as well as physical infrastructure (Taylor, Iseki and Garrett 2000).
1.3 Research Questions and Objectives
Both freight and public transit operations come with a variety of challenges, many of which present opportunities for collaborative efforts that could benefit both sides. Moving freight on underutilized public transit vehicles and networks could save money for freight operators and provide revenue for transit agencies while minimizing the impacts of trucks on the transportation network and environment. Freight vehicles have difficulty accessing downtown areas – the same areas that are well served by public transit, but could freight service be added to transit vehicles without hurting passenger operations? While there are potential benefits, are they worth the associated costs and risks? In order for operations to work, infrastructure upgrades would be needed in stations and on transit vehicles not intended to move goods; with freight operators operating at low profit margins and transit agencies operating at a deficit, where would this money come from? Freight operators and transit agencies operate with highly different objectives with the former looking to maximize profit and the latter primarily looking to
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provide a social need serving transit riders. Would these two contrasting groups be able to work together to plan, design, and operate a service that works for both parties? What kind of goods would be suitable for these operations? What kind of transit vehicles?
This thesis attempts to answer these and other questions related to Freight on Transit (FOT), which is defined as follows:
Freight on Transit: a trip that uses public transit vehicles or infrastructure to move things other than people
While FOT is a new term, it is not an entirely new concept and has been referred to previously as light rail freight (Arvidsson 2010), cargo tram operations (Regue and Bristow 2012), shared track operations (Resor 2003) and mixed goods service (Sivakumaran, Lu and Hanson 2010). FOT includes all of these and more. It can mean moving goods alongside passengers on buses, attaching cargo trailers to transit vehicles, operating freight vehicles between transit trips on subway lines, etc. There are relatively few examples of FOT worldwide, and even fewer in North America, because many practitioners are resistant to the idea of combining goods and passenger movements as it is not central to the mandates of public transit agencies, involves the cooperation of conflicting stakeholders, and is perceived as a large shift in the freight industry which can be resistant to change. Transit operators might not comprehend how goods movement could coexist with passenger operations on transit networks, while freight professionals might not realize either the potential or the limitations of using transit networks as a part of their supply chains. Because of the unconventional nature of FOT and the opposing goals of stakeholders, it is difficult to connect necessary decision makers especially when performing day to day operations, whether as a public transit agency or freight forwarder, can be extremely challenging on its own. In this study, the Delphi method was used to engage a heterogeneous group of transportation experts from academia, government and the private sector with expertise in freight, public transit, airport planning, intelligent transportation systems, urban planning, and economics in order to explore FOT, compile a body of FOT knowledge and develop FOT expertise. The Delphi is a multi-round, anonymous, iterative survey process that can be used to
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generate a consensus or “generate the strongest possible opposing views on the resolution of a policy issue” with this study using it for the latter application (Turoff 1971). The FOT Delphi Study had two primary research objectives:
To explore the most important issues surrounding FOT operations (positive impacts, negative impacts, challenges)
To build and evaluate potential FOT operating strategies in the Greater Toronto and Hamilton Area
A traditional Delphi process was used to accomplish the first research objective while the second objective was achieved using a modified version of the Delphi method and scenario building techniques to design FOT operations based on the aggregate group opinion of the heterogeneous expert panel. Both objectives were carried out in parallel on three separate web based surveys with each successive survey being designed based on responses from previous rounds. The final result were lists of the main positive impacts, negative impacts, and challenges of FOT operations; five potential FOT operating strategies using transit networks in the GTHA; and an evaluation of the GTHA’s potential for FOT.
1.4 Thesis Structure
Chapter 1 introduced the motivation for studying the integration of freight and transit operations, the main research objectives and the selection of the Delphi method. Chapter 2 provides a summary of existing and theoretical FOT operations as well as a literature review of other studies using the Delphi method to study transportation. Chapter 3 presents the research method including the standard Delphi procedure and key methodological decisions, while chapter 4 gives a detailed description of the three FOT Delphi surveys. Survey results are analyzed and discussed in chapter 5 and chapter 6 concludes with a summary of key findings, an evaluation of the survey process, and future directions for FOT both in general and in the GTHA.
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2 Chapter 2: Literature Review 2.1 Existing FOT Operations Though there are several operations that integrate passengers and goods movement on the same networks and/or vehicles, this is the first to refer to them all collectively as FOT. Many of the following FOT operations were found through literature review while others were related by Delphi panel members enforcing the notion that a Delphi process can “provide a more updated exchange of scientific or technical information than a literature search by drawing upon current knowledge of experts” (Delbecq, Van de Ven and Gustafson 1975). For the purposes of this study, FOT operations are divided into two types: those that move freight using existing public transit trips (FOT-EX) and those that move freight using new trips on public transit infrastructure (FOT-NEW).
2.1.1 FOT-EX: Freight on Existing Public Transit Trips FOT-EX operations increase the efficiency of transit trips by adding freight to passenger service. Goods may be located alongside passengers, in separate cargo areas, or in trailers attached to the vehicle. They may be operated by a public transit agency or the arrangement may be informal, with users taking advantage of the speed, price, and convenience of public transit when transporting smaller items in congested areas. Notable FOT-EX operations include: Greyhound Courier Express (Canada) / Greyhound Package Express (USA) – Greyhound is an intercity bus operator that offers courier services within Canada and the USA with parcels travelling in luggage bays or cargo trailers. The service is an add-on to generate revenue and offset the high cost per passenger mile on rural routes while providing deliveries to areas not typically served by express carriers (Lindly and Hill 2002). Greyhound has the most expansive package service in North America but other intercity bus operators carry packages with some reporting freight revenue exceeding revenue generated by ticket sales (Higgins, Warner and Morgan 2011). Most of the revenue generated from bus parcel service is from business to business deliveries (Greyhound 2012). No examples were found of North American regional or local transit agencies currently offering parcel services, but GO Transit, the inter- regional public transit system in the GTHA, used to deliver parcels on buses before the service was discontinued in the 1970s (Armstrong 2012).
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Matkahuolto (Finland) – Besides intercity deliveries, the Finnish bus operating conglomerate, Matkahuolto, offers local courier service to roughly 10,100 locations across the country as owners of almost 400 municipal and regional bus companies (Niemimukko 2011). Matkauholto`s freight service takes advantage of existing infrastructure as nearly 85% of public transit trips in Finland (outside of the Helsinki Metropolitan Area) are made by bus (Linja- Autolitto 2012). This additional revenue is used to improve passenger services, and freight capabilities strengthen the business case for adding new routes to less populated areas. Though drop-offs and pickups are usually made at registered agencies, customers may also give packages right to the driver making network coverage nearly ubiquitous in both urban and rural areas (Matkahuolto 2009). ic:kurier (Germany) – ic:kurier, operated by Lufthansa Cargo is the most notable FOT- EX operation using a rail network by means of an official agreement by partnering with Deutsche Bahn, the German national railway company (Lufthansa Cargo 2012). ic:kurier offers regular and frequent same-day delivery of high-value documents to 140 locations in Germany as well as to Vienna and Paris. Deliveries are insensitive to weather and traffic conditions and competitive to air service in terms of both cost and time. As packages are monitored by train operators, the service requires no vehicle upgrades. VIA Rail, Canada’s national railway and Amtrak, the intercity rail operator in the USA offer package services to their customers called VIAPAQ and Amtrak Express, respectively (VIA Rail 2012; Amtrak 2012). VIAPAQ offers same day deliveries but the trips are not nearly as frequent as the 20+ daily trips offered between certain routes by ic:kurier and Amtrak express does not offer same day deliveries with transit times listed anywhere between 3-7 days (VIA Rail 2012; Lufthansa Cargo 2012; Amtrak 2012). A-Way Express (Toronto, Canada) – A-Way Express is one of at least four Toronto- based courier companies that uses public transit to make deliveries, giving couriers a transit pass, or metropass, rather than a bike or car (A-Way Express 2012). Metropasser couriers provide low emissions, cheap, and fast deliveries, especially during congested periods while avoiding variable fuel and parking costs associated with van and truck operations. Good Foot Delivery and Greenteam Courier are other Toronto companies that use metropassers while QA Courier employs them in multiple Canadian cities (Good Foot Delivery 2012; Greenteam Courier 2012; QA Courier 2012).
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JogPost/DHL (London, England) – A unique application of metropasser deliveries was implemented by the German logistics company, DHL and Jogpost, a British pamphlet distributer, during the 2012 Olympic and Paralympic Games in London. Jogging couriers using the public transit network were able to make deliveries as usual without adding to or being affected by the 30% increase in roadway traffic related to the Games (Logistics Manager 2012). It is expected that metropassers operate in many other cities and countries but no information was found on their operations. Dabbawala (Mumbai, India) – The Dabbawala are a team of roughly 5,000 deliverymen moving 200,000 hot lunches prepared in the suburbs by office workers’ wives to their husbands in the urban core of Mumbai (Patel and Vedula 2006). The multimodal supply chain uses the suburban rail network for long haul distances moving large volumes of aluminum lunch boxes, or “tiffins”, outside of crowded AM peak periods with first and last mile legs being done by walking or cycling couriers. The impressive supply chain, which is reported to have only one error for every sixteen million deliveries, is made up of a “complex series of collection zones, sorting points, and delivery zones supported only by a manual coding system … made up of only numbers and colors because 50% of the employees are illiterate” (Moore 2011) . The success of the Dabbawala shows the ability of FOT-EX operations to capitalize on the unique characteristics of the transportation network, travel patterns, and human capital to provide a niche service while minimizing the impact of deliveries. Other FOT-EX operations may exist informally or even illegally but these are the most notable.
2.1.2 FOT-NEW: New Freight Trips on Existing Public Transit Infrastructure FOT-NEW operations differ from FOT-EX as they move freight on new trips using public transit infrastructure. The following examples are exclusively rail operations as no examples of FOT-NEW operations were found using buses. FOT-NEW is typically higher impact and more expensive than FOT-EX and requires official partnerships or lease agreements between shippers and transit agencies as well as moderate-to-heavy investment in spur tracks, vehicles, and/or vehicle modifications. The main advantages of FOT-NEW are reduced congestion, emissions, delivery time, and delivery costs. Following are notable operations, many
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of which have been investigated more closely by Arvidsson (2010) and Regue and Bristow (2012). CarGo Tram (Dresden, Germany) – The CarGo Tram, operated by auto manufacturer Volkswagen in cooperation with DVB, Dresden’s public transit operator, moves car parts between a distribution center and a factory along a four kilometer section of the passenger tram network with spur connections to the two activity nodes. Each 60-meter long CarGo Tram runs between passenger trams during service hours carrying up to 60 tons of goods, eliminating three truck movements with each trip (Arvidsson 2010). The CarGo Tram has never disrupted passenger travel, is competitive with trucks, and was built with minimal initial investment due to the proximal locations of the activity nodes to the tram network (Regue and Bristow 2012). The operation was motivated by Volkswagen’s desire to construct a “transparent factory” where people could witness the car manufacturing process from start to finish. Serving the factory by CarGo Tram was the only way to allow for an attractive location without generating truck trips in a downtown core highly sensitive to congestion (DVB 2012). Cargotram (Zurich, Switzerland) – The Zurich Cargotram, a partnership between the city’s tram operator and waste collection agency, moves bulky garbage and recyclables from drop-off points to processing plants located near the tram network. The trams are faster and cheaper than garbage trucks, operating in a dedicated right of way, free of congestion related costs and delays (Arvidsson 2010). The Cargotram has annual savings of 37,500 liters of diesel and 5 tons of CO2 from the elimination of 5,000 km of truck trips and 960 hours of idle time, numbers that do not include savings related to the elimination of passenger trips to and from waste processing plants (Neuhold 2005). This operation had low start-up costs (~32,000 €) due to the existing network alignment and the conversion of retired passenger trams into waste carrying vehicles (Neuhold 2005). Guterbim (Vienna, Austria) – Seeing the success of operations in Zurich and Dresden, Vienna’s public transit agency piloted a freight tram operation, the Guterbim, in 2005, using it to transport spare vehicle parts between a warehouse and maintenance facilities (Ehrilch 2012). Despite a successful pilot, the agency had no success partnering with retailers as capital costs required contracts longer than anyone was willing to sign (Arvidsson 2010). That and a lack of political backing halted Guterbim operations though the trams themselves are still functional (Regue and Bristow 2012).
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Tramfret (Paris, France) – The Paris Transport Authority and the Ile de France Regional Transport Authority launched a successful freight tram pilot test in 2011, inserting empty trams into an 8 km section of the passenger network (Alcaraz 2012). A survey of shippers will be launched in early 2013 to assess shipper interest making Paris poised to become the next city making deliveries using FOT-NEW (RFF 2012). Supporters of Tramfret are hopeful that a suitable private partner will be identified as the Ile de France Regional Transport Authority has authority over nearly 100 km of tram lines in Paris, allowing for a range of potential collaborators (Alcaraz 2012). City Cargo (Amsterdam, Netherlands) – City Cargo was an attempt to implement freight tram delivery in combination with electric vehicles for last mile trips to supply shops in downtown Amsterdam (Arvidsson 2010). According to initial feasibility studies “up to half of [truck] movements in the city could be replaced by trams thus cutting pollution 20%” (Chiffi 2007). These claims and a successful pilot test in 2007 led to considerable interest and financial support as City Cargo generated over 69 million Euros from investors. The operation eventually failed when the tram operator, GVB, who were leasing the lines to City Cargo, demanded the construction of additional tracks to eliminate the risk of passenger disruptions. Unable to afford the upgrades or convince or the city to subsidize the additional 5.6 million Euros required to meet GVB’s demands, City Cargo went bankrupt in 2009 (Chiffi 2007). Garbage Subways (New York, USA) – New York’s MTA uses late night system downtime and modified subways to empty 90 tons of garbage from subway stations every day. Each of the eight garbage trains consists of three flatbed cars containing rows of wheeled dumpsters connected to gutted passenger cars that serve as staff rooms for cleaning crews. While the garbage trains have a positive effect on both congestion and emissions, they bring some negative impacts as their arrival is an annoyance for passengers waiting for trains late at night and their presence contributes to rodent infestations in the network (Donohue 2011) Toronto had a similar operation emptying garbage from stations using gutted subways but switched to truck operations in 2000 when one of them caught fire destroying the train and damaging a station (Bateman 2012). San Diego Imperial Valley (San Diego, USA) – San Diego Imperial Valley Rail Road (SDIV) is a short haul freight mover that shares tracks with the San Diego Trolley, a light rail system operated by the San Diego Metropolitan Transit System (Union Pacific 2012). It is the
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most notable shared track operation in the USA made possible by a waiver granted by the Federal Railway Administration (FRA) that allows freight movements on public transit tracks so long as freight and transit vehicles do not occupy the tracks at the same time (Resor 2003). The temporal separation specified in the FRA waiver limits freight services to short time windows at night, leaving SDIV only enough time to send a single freight train carrying sand, aggregate and other materials between San Diego and a transfer station near the Mexican Border between 1 AM and 4 AM each morning (Domen 2012). The San Diego Trolley lines were built as exclusively freight corridors, then switched to shared use when the trolley system was built in 1981 (Resor 2003). As of 2008 there were 9 such shared track operations in the USA with SDIV being the most notable and moving the most freight on urban transit lines (Pritchard 2008). While other passenger rail systems share tracks with freight trains, SDIV operations are unique in that the shared operations occur on lines used by light rail transit vehicles as opposed to operations like GO Transit in Toronto, and other intercity rail operators where freight trains share tracks with heavy rail passenger trains. Table 2-1 summarizes notable FOT-EX and FOT- NEW operations.
2.1.3 Transit on Freight In many ways, operations like SDIV and GO Transit are more transit on freight than freight on transit as transit service was added to lines originally used to move freight, leading to freight services eventually being almost or completely replaced by passenger operations, a practice that is a feature of many of the operations under the FRA shared track waiver (Resor 2003). Certain European cities have used freight lines to create versatile passenger networks without having to reduce or limit freight service, most notably in Karlsruhe, Germany where “tram-trains” operate on light rail tram lines in the urban center and seamlessly connect to heavy rail freight lines in the countryside where they act as commuter rail vehicles. This allows people living in the suburbs access to high order urban transit without having to transfer between trains (Chisholm 2002). While worth mentioning, this creative use of freight infrastructure to move passengers is beyond the scope of this study of creative ways to use transit infrastructure to move freight.
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Table 2-1 Summary of Existing FOT Operations
Operation FOT-EX / Similar Goods moved Service area Cargo Location Status? (Location) FOT-NEW operations
Greyhound Packages and 2,300 rural and urban Trailers attached to Many Courier and FOT-EX parcels up to destinations in North buses or bus luggage Ongoing intercity bus Package Express 100 lb America bays operators (Canada, USA)
Packages and Mathkahuolto 2,000 urban and rural Bus luggage bays or FOT-EX parcels up to 55 Ongoing N/A (Finland) destinations in Finland near bus driver kg 140 Stations in -VIAPAQ ic:Kurier Packages and Separate area in FOT-EX Germany; Paris and Ongoing -Amtrak (Germany) parcels up 25 kg passenger coach Vienna Express -Good Foot A Way Express Packages up to Areas in Toronto served Couriers riding transit FOT-EX Ongoing -QA (Toronto) 15 lb by rapid transit network vehicles -Greenteam
Package that can Operational DHL/JOGPOST Areas in London served Couriers riding transit FOT-EX be lifted by during 2012 N/A (London) by rapid transit network vehicles couriers Olympics
Dabbawala Office buildings in Delivery men riding FOT-EX Hot lunches Ongoing N/A (Mumbai) Mumbai transit vehicles
CarGo Tram Factory and distribution FOT-NEW Car parts Freight only tram Ongoing N/A (Dresden) center
Cargotram Recylables and 9 collection points and 1 Garbage bins hauled FOT-NEW Ongoing N/A (Zurich) electronic waste recycling plant by tram
Guterbim Spare transit Garage and satellite Stalled after FOT-NEW Freight only tram -Tramfret (Vienna) parts maintenance facilities 2005 pilot
Identifying Tramfret Retail Downtown Paris FOT-NEW Freight only tram private sector -Guterbim (Paris) (proposed) (proposed) partners
Food to shops City Cargo FOT-NEW and Downtown Amsterdam Freight only tram Bankrupt N/A (Amsterdam) Supermarkets
MTA Garbage Waste from New York City Subway Dumpsters on flatbed -Toronto Metro FOT-NEW Ongoing Subway Stations Stations cars Tokyo Rose (New York)
Imperial Valley Various – sand, Downtown San Diego -8 others FOT-NEW Railroad aggregate, with connection to Freight Train Ongoing under FRA (San Diego) lumber, etc. Mexican Border waiver
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2.2 Proposed FOT Operations
Other researchers have explored freight and transit integration, advocating and/or demonstrating the feasibility of FOT in Barcelona, San Francisco and Gothenburg. An economic feasibility study of two freight tram operations in Barcelona found that a garbage tram had rapid return on investment (ROI) while trams serving malls would only be feasible with subsidies (Regue and Bristow 2012). Another study modeling the movement of express air packages between airports and sorting hubs using the Bay Area Rapid Transit Network (BART) in San Francisco showed that with a high initial investment and guaranteed demand, the service would save money compared to trucking but would not largely reduce congestion (Sivakumaran et al. 2010). As with the Barcelona study, the FOT scenario in San Francisco would only be feasible if subsidies were provided with ROI increasing with increased subsidies. Finally, after an in-depth investigation of the reasons for the failure of Amsterdam City Cargo, Arvidsson (2010) presents a strategy for developing a potentially zero emissions freight operation in Gothenburg, Sweden. He argues that an operation similar to City Cargo would be feasible on the well developed tram network in Gothenburg but would be more likely to succeed if it were small scale, open source, and made use of “roll on roll off” transfers between freight trams and electric distribution vehicles.
2.3 Summary of Findings As seen from existing operations, successful FOT operations tend to focus on either specific or small commodities, take advantage of existing infrastructure to minimize startup costs, and/or operate at times when networks are not crowded - meaning outside of AM and PM peak periods. More recent successes have been FOT-NEW operations in Dresden and Zurich while FOT-EX operations such as the intercity bus parcel and metropasser models have been profitable for decades. Perhaps the most complex and famous operation is also the most enduring as the Dabbawala of Mumbai have operated for over 125 years (Patel and Vedula 2006). The failed operations in Amsterdam and Vienna attempted to emulate successful cargotram models in Dresden and Zurich but lacked key elements that made the latter two successful. Clearly, having a well-developed tram network and advocates championing the operation is not enough to make FOT work as both Vienna Guterbim and Amsterdam City Cargo
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failed due mainly to internal barriers like a lack of focus, a lack of support, and difficulty coordinating multiple stakeholders. Proponents of Vienna Guterbim likely figured their successful pilot test would attract investors but could find none able to meet the length or terms of contracts necessary for infrastructure upgrades. Had City Cargo not set the lofty goal of eliminating 50% of truck movements during feasibility studies and started smaller scale, they likely would have been able to meet the financial demands of the tram operator. For this reason, proponents of Paris Tramfret are approaching implementation with caution and engaging private sector partners before making any major investments. Even the trams run during pilot testing were regular passenger trams. Economic analyses of FOT-NEW freight tram operations all seem to come to the conclusion that subsidies are needed for operations to succeed which motivates the claim made by Arvidsson (2010) that an open source freight tram system would be best. The government could not justify providing subsidies to a single company but might be able to justify subsidizing a system that could be used by multiple freight operators, similar to the way that governments subsidize roads used by multiple trucking companies. Such an operation would have to be carefully thought out and managed in order to be able to function without disrupting passenger travel. The diversity of existing operations in terms of logistics, vehicle type, hours of operation, commodities carried, etc. indicates that each transit network may show potential for widely different FOT operations showing little resemblance to those listed. An FOT system in a different city might have an entirely different impact on the network and come with an entirely new set of challenges not accounted for previously. The author chose to conduct a Delphi study to verify claims made about FOT, identify issues not revealed in previous studies, and develop new and innovative FOT operations.
2.4 The Delphi Method
The Delphi method, or Delphi technique, is a research tool that was first developed by researchers at the Research and Development Corporation (RAND) in the 1950’s as a forecasting tool for the United States’ military to predict the impacts of emerging technologies on future warfare (Stitt-Gohdes and Crews 2004). The Delphi method uses multiple surveys and iterative feedback to generate consensus among a group of experts. On the first questionnaire, individuals are asked to respond to broad questions and each subsequent questionnaire is built
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upon these responses creating an iterative process that continues until consensus has been obtained, enough information has been generated, or a pre-defined stopping point is reached process (Delbecq et. al 1975; Dalkey 1969).
Since its origins as a forecasting tool, the Delphi method has evolved into a versatile research technique that can be applied in a number of different situations. In the late 1960s, Linstone and Turoff (1975) developed a method for using the Delphi for evaluating policy decisions. While the traditional Delphi attempts to generate consensus among a group experts, the Policy Delphi “seeks to generate the strongest possible opposing views on the potential resolution of a major policy issue” (Linstone and Turoff 1975). The following key distinction separates the Policy Delphi from the traditional Delphi:
“The Policy Delphi … rests on the premise that the decision maker is not interested in having a group generate his decision; but rather have an informed group present all the options and supporting evidence for his consideration.” (Linstone and Turoff 1975, 80)
A third variation of the Delphi, called the Decision Delphi, was proposed by Rauch (1979) who suggested that the Delphi could be used to make actual policy decisions by populating the expert panel with panelists who are recruited not because of their expertise but with regard to their actual position in the decision making hierarchy. By carrying out a Delphi process with participants that have the authority to make decisions, “reality is not predicted or described: it is made” (Rauch 1979).
Following the first public description of the Delphi method in 1964 and the development of the policy and decision Delphi techniques in the 1970s, the Delphi has been used to perform research in a variety of fields including curriculum development, nursing, knowledge sciences, information technology, accounting, psychology, career development and urban planning, to name a few (Novakowski and Wellar 2008). Robust compilations of studies using the Delphi for undergraduate, graduate, and corporate research have been compiled by Skulmoski et al. (2007), Linstone and Turoff (1975) and Dfouni (2002). This work will limit its review of other Delphi studies to those that employed it in the fields of transportation, logistics, and scenario building – subjects all closely related to the primary research objectives. Some of the previous
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transportation, logistics, and scenario building Delphi studies provided useful research techniques while others indirectly hinted at the emergence of FOT.
2.4.1 The Delphi Method for Transportation and Logistics Planning
Starting in the field of logistics, von der Gracht and Darkow (2010) used the traditional Delphi method and a group of 30 logistics professionals to predict the future of the global logistics industry. Experts were presented with a list of 30 scenarios and were asked to rate each in terms of likelihood, impact, and desirability (von der Gracht 2008). Modified versions of these scales were used in this study to determine the most desirable aspects of FOT operations. A larger scale logistics Delphi was conducted by DHL to predict global developments, habits of future customers and how logistics will be altered in the coming years. 81 statements were presented to participants who estimated the likelihood of each occurring over forecasting periods of 5, 10, and 10+ years (Deutsche Post DHL 2009). While nowhere in these 81 statements was there a direct mention of FOT, certain scenarios rated as “likely to occur” by the expert panel would certainly encourage it, including a doubling in oil prices by 2015, the emergence of renewable technologies, a shift towards competitors collaborating to achieve sustainability, the emergence of zero-emissions cities, and a willingness of the consumer to pay more for “green” products and services (Deutsche Post DHL 2009). A final study using the forecasting Delphi to study the future of freight resulted in experts predicting the future mode split of trucks would drop from 64% in 2006 to 59% in 2020. At first glance this result seems to encourage FOT uptake, but a reported standard deviation of 6% shows a large degree of uncertainty regarding the future of the logistics industry (Piecyk and McKinnon 2010).
Transportation planning Delphi studies were useful in developing many of the research methods employed in this study. In terms of building and evaluating scenarios, Shiftan et al. (2003) conducted a two round Delphi asking experts to rate policy decisions based on probability and desirability to develop scenarios for future transportation development in Tel Aviv. This study used similar scales and questions to design potential FOT operations. A study by Brennan Ramirez et al. (2006) determining the top 10 performance indicators of activity friendly communities from a list of 230, provided useful techniques for paring down large lists of items by identifying and combining duplicate items. Finally, a Delphi of done by MacCarthy and Atthirawong (2003) modelling the decision making process for businesses choosing to send
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manufacturing operations overseas provided useful methods for developing ordered lists of qualitative measures as well as methods for aggregating open ended responses of a large number of experts.
The most similar work found to a Delphi studying FOT, was one examining the likelihood of a modal shift from trucks to short sea shipping in the UK (Saldanha and Gray 2002). The study brought up many issues relevant to FOT implementation as some of the largest barriers to the modal shift included a fear of change exhibited by freight professionals, a lack of collaboration among competitors, and the desire to avoid double handling of freight. Perhaps the most intriguing point brought up by this expert panel was general agreement on the point that the government should consider themselves justified in subsidizing coastal shipping as the development and maintenance of roads has already established an uneven playing field where trucks have a distinct advantage over other modes (Saldanha and Gray 2002). This same point would be brought up by members of the Delphi panel in this study regarding governments subsidizing FOT.
This brief review demonstrated that the Delphi is an established tool for exploring transportation and logistics issues with many of the studies providing critical guidance during survey design, delivery, and analysis. While there was no direct mention of FOT in any of them, certain studies may have unknowingly hinted at its emergence.
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Chapter 3: Research Methods
A 3 round policy Delphi was conducted to investigate the most important issues surrounding FOT operations and to build and evaluate potential FOT operating strategies for the GTHA. The main research questions grouped under each of the two primary research objectives are presented in Figure 3-1.
Figure 3-1 Research Questions OBJECTIVE 1: Explore main issues of FOT operations
Question 1.1: What are the main positive impacts of FOT operations?
Question 1.2: What are the main negative impacts of FOT operations?
Question 1.3: What are the main challenges of implementing FOT operations?
OBJECTIVE 2: Build and Evaluate FOT operating strategies for the GTHA
What potential FOT operations could be integrated onto transit networks in Question 2.1: the GTHA?
Question 2.2: Which (if any) of these operations are the most feasible and/or desirable?
3.1 The Delphi Method
The Delphi method employed in this study is the Policy Delphi, an exploration tool that relies on multiple surveys of experts to explore an unresolved policy issue. It is different than the traditional Delphi as there is no expectation of reaching a consensus, only to explore an issue, in this case, moving freight on public transit networks. There are no strict guidelines for conducting a Delphi study meaning that many of the design decisions are left to the judgment of the research team (Hasson, Keeney and McKenna 2000). Though there is no fixed method, for a study to qualify as a Delphi, it must include at minimum the features shown in Figure 3-2. While there are some so called Delphi studies that do not include all of these features, a true Delphi process is a series of iterative surveys interspersed with feedback that engages experts and uses statistics to describe their aggregate opinion.
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Figure 3-2 Key Delphi Features • Anonymity • Iterations • Controlled Feedback • Statistical Group Response • The Use of Experts
(Dalkey 1969) (Turoff 1970) (Rowe and Wright 2001) (von der Gracht 2008) (Goodman 1987)
3.1.1 Justification
Linstone and Turoff (1975) advocate the use of the Delphi for studying issues that meet one or more of the criteria listed in Figure 3-3 and an argument can be made that FOT fits all of them. As few operations exist, especially in North America, a Delphi will be useful to discover the opinions of decision makers regarding merits and shortcomings before analyzing detailed operations that may be rejected by those with the authority to implement them. Potential FOT operations could involve a variety of logistics movements on a range of transit networks and in order to explore the full range of possibilities, inputs are needed from many heterogeneous decision makers making face to face meetings infeasible due to time and financial restraints. As disagreements are likely to arise especially between freight and transit professionals, anonymity and the use of a facilitator are both justified in order to ensure that the interests of all parties are considered and that the group is not dominated by one or more highly influential group members.
Figure 3-3 Criteria Motivating a Delphi Study
• The problem does not lend itself to precise analytical techniques but can benefit from subjective judgments on a collective basis • More individuals are needed than can effectively interact in a face-to-face exchange • Time and cost make frequent group meetings infeasible • Disagreements among individuals are so severe or politically unpalatable that the communication process must be refereed and/or anonymity assured • The heterogeneity of the participants must be preserved to assure validity of the results, i.e., avoidance of domination by quantity or by strength of personality ("bandwagon effect") (Linstone and Turoff 1975)
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Turoff (1971) and von der Gracht (2008) suggest that a policy Delphi should be able to serve any one or a combination of the objectives shown in Figure 3-4, all of which are relevant to this study. Sections of this study dedicated to the exploration of FOT issues exposed and explored assumptions causing changes in judgment, correlated informed judgment on the topic of FOT, and educated respondents that had previously had little knowledge of FOT operations. The development of potential FOT operating strategies in the GTHA estimated the impact and consequences of a range of alternatives and examined the acceptability of each. Though this study was not able to consider all possible options for moving freight on transit networks, it did achieve all of the other listed objectives.
Figure 3-4 Typical Objectives of a Policy Delphi
• To determine or develop a range of possible alternatives • To explore or expose underlying assumptions or information leading to differing judgments • To seek out information which may generate a consensus of judgment on the part of the respondent group • To correlate informed judgments on a topic spanning a wide range of disciplines • To ensure that all possible options have been put on the table for consideration • To estimate the impact and consequences of any particular option • To examine and estimate the acceptability of any particular option • To educate the respondent group as to the diverse and interrelated aspects of the topic
(Turoff 1975) (von der Gracht 2008)
3.1.2 Strength and Weaknesses
The anonymity and flexible structure of the Delphi makes it a powerful communication tool. Quite often in transportation planning, policy decisions are made by high status individuals based on analysis performed by lower level employees resulting in a disconnect between knowledge and decision making. The Delphi allows for communication between all groups, allowing low status individuals to engage with high ranking officials and high ranking to be a part of initial analysis. As well, in a Delphi, participants can speak freely and the group will not be dominated by members with dominant personalities as the facilitator will not allow it. The process allows conflicts and disagreements to be discovered and the iteration interspersed with feedback allows them to be explained. Participants may abandon initial positions based on new information received through feedback without appearing to be weak in the eyes of their peers.
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That there are no face to face interactions means the Delphi can engage a large number of busy individuals from a range of fields and locations, and participants can complete surveys at the time and location of their choice without having to coordinate with others’ busy schedules. Finally, as there is no fixed method, the facilitator is able to modify study objectives and survey design as more interesting and critical issues are discovered by the expert panel.
Though powerful, the Delphi also has many limitations, a large number of which stem from the fact that there are no set guidelines for conducting a Delphi study. The “elusiveness of a fixed universally agreed working upon definition of Delphi” leaves many of the major methodological decisions in the hands of the facilitator which increases the likelihood of errors and sloppy research (Sackman 1974). Another critique is the fact that the eventual outcomes of the study are not facts but the opinions of a specific group of experts and that a second group going through the exact same process could produce an entirely different set of outcomes (Goodman 1987). As well, the definition of expertise and selection of panel members are decisions left to the research team leading to inherent bias. Anonymity is able to produce honest discussions but also has the potential to produce thoughtless answers as it can lead to a lack of accountability. Other critics of the Delphi suggest that the effect of feedback in between rounds is minimal, and that experts tend to ignore feedback that contradicts previously held beliefs (Scheibe, Skutsch and Schofer 1975). As well, it is up to the facilitator to decide what feedback to present which can result in the presentation of skewed opinions that may not be representative of the entire group.
Other inherent problems are related to study length, questionnaire design and the process of conducting multiple surveys. For starters, there is no standard regarding the number of Delphi rounds with studies ranging anywhere from one to thirteen (Skulmoski, Hartman and Krahn 2007; von der Gracht 2008). As well, statements on Delphi questionnaires may be interpreted in many different ways and there is no agreement regarding the adequate length of statements, the number of statements to include, or the appropriate wording of questions (von der Gracht 2008; Rowe and Wright 2001; Linstone and Turoff 1975). Finally, designing, testing, and distributing multiple questionnaires is very time and resource intensive for the research team and a long drawn out process may lead to high dropout and low response rates from a busy expert panel
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(Hsu and Sandford 2007a). Figure 3-5 summarizes the strengths and weaknesses of Delphi studies.
Figure 3-5 Delphi Strengths and Weaknesses
Strengths Weaknesses
• Is flexible • No set guidelines on how to conduct a • Engages participants from a range of Delphi backgrounds and remote locations • Results based on the opinions of a single • Can engage many busy individuals group of experts • Anonymity promotes an honest view • Expert selection based on biased • Eliminates confrontations and time judgment of research team wasting • Anonymity may produce thoughtless • Multiple opinions answers • Eliminates group domination by high • Effect of feedback may be minimal status individuals • Questionnaires likely to be ambiguous • Can describe opinions statistically or confusing • Can discover and explain disagreements • Responses may be affected by current state of mind of participant or other external factors • Time and resource intensive • High dropout rates are common
Being aware of strengths and weaknesses allowed for a more careful process as well as a more realistic interpretation of the study’s results. The flexibility of the method was considered a strength as it allowed the study to change with the opinions of the panel, and while there is no fixed method to fall back on, there were many best practices and good examples of Policy Delphis by which to base methodological decisions. Regarding feedback and survey design, it is up to the facilitator to present as much honest feedback as possible without burdening participants, and to pretest questionnaires to reduce confusion and ambiguity, all techniques employed in this Delphi study. Another method of reducing response ambiguity employed in this study was to provide space on surveys for participants to justify and explain their answers.
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3.2 Typical Delphi Procedure
This study was loosely based on guidelines set out by Hasson, Keeney, and McKenna (2000), who divided the Delphi into the four phases shown in Figure 3-6. During the initial phase the subject is researched through literature reviews and informal interviews to determine if a gap exists and whether the Delphi method is an appropriate tool to fill that gap (Skulmoski et al. 2007). Once it is decided that a Delphi will be conducted, the first questionnaire is developed, tested, and sent out to the desired participants. Responses from the first round questionnaire are analyzed by the facilitator who designs the second questionnaire based on these results. After testing, the second questionnaire is sent to the same participants along with feedback describing the general opinion of the group. Participants respond to the second survey and this process is repeated in an iterative manner until a stopping point is reached. While this general process is the same across different Delphi studies, there is a high degree of variability regarding the number of rounds, the definition of expertise, the size and makeup of the expert panel, survey evaluation methods, statistical methods, and the type of feedback provided to respondents (Dfouni 2002). Following is a discussion of how these vary across Delphi studies and the choices made regarding each one in this study.
Figure 3-6 Typical Delphi Process
START! • Preliminary research • Expert panel identification 1. Exploration of the subject and recruitment • Development and testing of first questionnaire Send Survey 1 • Analysis of first questionnaire • Development and testing of second 2. Discovery of Opinions questionnaire • Continued expert recruitment
Send Survey 2 • Analysis of second questionnaire 3. Determining • Development and testing of third questionnaire most important • Recruitment concluded issues Send Survey 3 • Analysis of third questionnaire 4. Data • Preparation of a report to present conclusions, major points of analysis and disagreement, final recommendations, etc. to send to expert conclusions panel Send Final Report
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3.2.1 Number of Delphi Rounds
Standard Delphi studies are conducted over three rounds, with studies generally varying from two to five with more unconventional ones using anywhere from one to thirteen (Skulmoski et al. 2007; von der Gracht 2008). Skulmoski et al. (2007) conducted a review of 41 Delphi studies done at the graduate level finding 29 three round Delphis, 7 two round Delphis, 4 four round studies and a single study employing five Delphi rounds. While Turoff (1971) and von der Gracht (2008) both suggest that for Policy Delphis, “4-5 rounds are needed until there are sufficient results for the final committee to formulate a required policy”, this study was not looking to implement policy but rather to explore FOT and test the feasibility and acceptability of different operating strategies (von der Gracht 2008). The decision therefore was made to conduct the study over three Delphi rounds as this is the most common and also the most realistic given time constraints. In general, the number of rounds depends on the amount of time available, whether or not there is a pre-determined stopping criteria (e.g. level of consensus), and how long participants remain interested (Hasson, Keeney and McKenna 2000). Too few rounds will produce results that may not be meaningful and too many rounds may exhaust the topic or fatigue and anger participants (Schmidt 1997a). Few studies use more than three rounds and in fact, some argue that answers may even decrease in accuracy in rounds four and beyond due to participant fatigue and carelessness (Martino 1972).
3.2.2 Defining Expertise and Selecting the Number of Participants
Defining and identifying experts is another key Delphi element that varies from study to study. The rationale for using experts is that they are “more likely than non-experts to be correct about questions in their field” (von der Gracht 2008). The quality of data produced by the Delphi will be directly related to the quality of the participants and therefore careful consideration must be made in defining and selecting the appropriate ones (Hsu and Sandford 2012). Linstone and Turoff (1975) suggest that experts should have knowledge of the subject as well as a desire to participate as a highly knowledgeable person will not be useful if they give no thought to the study. Adler and Zigilio (1996) provide a useful set of requirements in identifying potential Delphi experts and Delbecq et al. (1975) provide a useful set of factors likely to motivate an expert to participate with the two lists shown in Figure 3-7. The ideal expert will be willing, knowledgeable and interested enough to devote time to the Delphi study and must be
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Figure 3-7 Defining and Motivating Delphi Experts A good expert will have... An expert will participate if...
• knowledge and experience with the • he/she feels personally involved in the issues under investigation problem of concern • capacity and willingness to participate • he/she has pertinent information to share • sufficient time to participate in the • he/she is motivated to include the Delphi Delphi in their schedule of competing tasks • effective communication skills • he/she feels that they will gain information which is valuable and which he/she would otherwise not have access (Adler and Zigilio 1996) (Delbecq et al. 1975) able to communicate their opinions or the facilitator will spend excessive amounts of time deciphering responses.
These “expert motivating” criteria were applied to the topic of FOT, identifying the best experts as those that already have knowledge of FOT, those concerned about the ways that FOT might affect them or their business and those that are simply interested in learning more. Rowe and Wright (2001) recommend that “one should … choose experts whose combined knowledge and expertise reflects the full scope of the problem domain” and suggest a good way to do this is to develop a knowledge resource nomination worksheet (KRNW) to be filled in with stakeholders involved in fields related to all facets of the subject. For the FOT Delphi, the KRNW shown in Figure 3-8 was developed to guide the recruitment of a heterogeneous panel in terms of workplace sector (Academia, Public Sector, Private Sector, NGO) and field of expertise (Freight, Public Transit, Airport Planning, Environment, ITS, Planning, Economics). Okoli and Pawlowski (2004) recommend the split across these four workplace sectors as professionals working in each are likely to have different perspectives thereby ensuring a more complete range of opinions and viewpoints. The divisions of expertise were decided upon after reviewing existing and theoretical FOT operations and related literature. Experts were added to the KRNW as they responded in order to track and ensure panel heterogeneity.
Knowing the types of experts, the next step is to decide how many to survey. The review of graduate level Delphi studies included panels of anywhere from 3 to 345 members with ~80% of the studies containing 20-50 members (Skulmoski et al. 2007). Selecting the appropriate
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Figure 3-8 KRNW for FOT Delphi Expert Recruitment Workplace Academia Private Sector Public Sector NGO Freight/ Logistics
Public Transit
Environment/ Sustainability Traffic Engineering / ITS
Airport Planning Field of Expertise of Field Policy/ Planning
Finance/Economics
panel size involves tradeoffs. If the panel is too small, the study runs the risk of missing key issues while too large a panel can result in irrelevant arguments, more frequent conflicts, and information overload (Rowe and Wright 2001). As Delphi studies are often plagued by high dropout rates between rounds, another risk of having too small a sample is that these dropouts could significantly change results based on statistical tests. For studies using a heterogeneous sample, like this one, Delbecq et al. (1975) recommend that the panel size consist of anywhere from 20-40 members which matches well with the split in the review of graduate level Delphis done by Skulmoski et al. (2007). As FOT is a broad subject, the desired panel size was on the larger end of this spectrum with a minimum of 30 and a maximum of 40 members.
3.2.3 Survey Structure and Evaluation
After defining the number of Delphi rounds and the desired types and number of participants, decisions regarding survey structure and survey evaluation methods must be made. Typically, the first questionnaire is a “brainstorming” exercise involving open ended questions, but “brainstorming” may also be performed in focus groups or through literature reviews prior to the start of the Delphi process (Okoli and Pawlowski 2004). The traditional 3 round Delphi includes the brainstorming phase and two structured questionnaires (Linstone and Turoff 1975). The first questionnaire in this study was of the brainstorming variety containing a number of
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open ended questions about FOT with first round responses guiding the design of surveys 2 and 3.
The usual result of the brainstorming phase is a long list of items for each open ended question. Designing the second survey, involves compiling and organizing these into a list of the most frequent and compelling items that is more manageable for survey participants. The objective of the second survey is to determine which items are the most important which is typically done in one of three ways: 1) participants select a fixed number of items they consider to be important; 2) participants rank items against each other; or 3) participants rate all items on a Likert scale (Hsu and Sandford 2012; Okoli and Pawlowski 2004). Early Delphi studies only used selection and ranking approaches until Watson (1989) performed the first Delphi asking participants to rate issues on a scale. Since then many studies have employed the rating method based on the rationale that human beings have a limited capacity of processing information simultaneously making ranking exercises difficult (Dfouni 2002). Attempting to rank lists of N items can result in having to make up to pair-wise comparisons or 36 different judgments for a list of 8 items and up to 120 for a list of 16. Besides being more straightforward, rating has other advantages over ranking as a rating system generates data for each item, can more easily deal with tied items and allows for more detailed statistical analysis. As this study involved identifying important items from longer lists, rating type questions were used for most parts of the survey in order to generate more data and reduce survey completion time. The one section that used ranking type questions was the final evaluation of FOT operating strategies. As there were only five such strategies, issues related to ranking long lists did not apply.
The major decision to make in design of the final Delphi survey is how to determine which round 2 items will continue to be rated again in the final round. Items are typically sorted by relative importance based on either the median or the mean rating of expert opinion obtained in the second round (Powell 2003). Lists are then reduced by either keeping all items that obtained a certain minimum rating, or by selecting the top few (e.g. 5-10) factors (Dfouni 2002). For FOT issue exploration, the top 5 items based on mean rating continued to the final round, a decision made based on best practices and in order to minimize completion time of the final survey.
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3.2.4 Statistical Methods
When measuring group opinion using the Delphi method, Rowe and Wright (1999) recommended using statistics that measure the central tendency of the group opinion, the range of opinions and the level of consensus.
Central tendencies in Delphi studies are typically measured through the mean or the median with a small number of studies using the mode (Rowe and Wright 1999). The choice usually comes down to whether to use the mean or median, and ample research is available to support the use of either one as documented in literature reviews performed by Hanafin (2004) and others (Skulmoski et al. 2007). Both mean and median were measured in this study but it was the mean that was finally used as the measure of central tendency due mainly to the fact that using median values resulted in a large number of ties making it more difficult to use it to distinguish between important and unimportant items. In rating type Delphi studies, statistics that measure the range of opinions are the standard deviation, interquartile range (IQR) (e.g. measure of the spread of responses between the 75th and 25th percentiles), histograms, and/or the percentage of respondents answering above or below a certain threshold value (Rowe and Wright 1999). All of these were computed and explored for each of the Delphi items in this study to explore the range of answers. Finally, a Delphi study must include some statistical measure that describes the level of agreement among experts. Standard deviation and IQR provide some insight into levels of agreement as low values of these statistics mean that experts’ ratings tend to be similar. Consensus can also be measured by looking at how certain statistics change between rounds such as changes in mean, the changes in standard deviation, and changes in IQR (Hasson, Keeney and McKenna 2000). All of these were used to measure consensus in this study.
The final statistic used to measure consensus, and the traditional measure of consensus in Delphi studies is the Kendall coefficient of concordance (W). W indicates the current level of agreement between panel members when ranking items on a list (Dfouni 2002). W may also be used on rating type Deplhis by converting ratings into rankings. W ranges from 0-1, with 0 indicating complete disagreement and 1 indicating complete consensus. Schmidt (1997a) provides the guidelines in Table 3-1 to help interpret values of W but stresses to use them only as guidelines and not exact cut-offs.
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Table 3-1 Interpretation of Kendall's W
W Interpretation Confidence in Ranks
.1 Very weak agreement None .3 Weak agreement Low .5 Moderate agreement Fair .7 Strong agreement High .9 Unusually strong agreement Very High
Schmidt (1997)
Calculation of W is best described by Siegel and Castellan (1988) who present two ways to compute its value: for the case where there are tied values and the case where there are no tied values. This study involved many tied items, so W was calculated using the correction factor for ties. The following section describes the steps set out by Siegel and Castellan (1988) for calculating W among a group of N experts rating K items on a list. For each expert (E), Delphi items (D) are arranged based on their ratings from highest to lowest. Ratings are then converted to rankings (R).
Ei = expert i (1)
Dj = item j (2)