MIT/CMU Workshop Summary
April 16 – 17, 2009

The MIT / CMU Real-Time Rides workshop took place at MIT in Cambridge, Massachusetts on April 16th and 17th, 2009. The workshop was structured around topic-based sessions. The research team and select workshop attendees framed the topics in each session with short presentations. These presentations were followed by a structured discussion among all participants.

For each workshop session, this report provides a general description of the presentations given and more specific summaries of the group discussions that took place. To the degree possible, we have attempted to identify and emphasize the main themes that resonated throughout the sessions. We acknowledge that not all comments or questions brought up in the sessions are necessarily covered in this summary report. The report concludes by considering potential next steps that could be taken by stakeholders in the ridesharing industry.

Major Workshop Themes:

The two-day workshop covered a variety of topics, but four major ideas or themes emerged as critical to the success of ridesharing.

1. There is a strong belief that ridesharing is largely dominated by human behavior, preferences and perceptions as travelers make transportation choices. Technology can support rideshare adoption through, for example, added convenience and safety, but it is not sufficient for sustained improvement in rideshare participation. Service and cost characteristics, non-transport incentives and marketing efforts are viewed as critical to rideshare participation.

2. Additional data and better analysis of rideshare information is needed. This theme focused on the need to understand the size of the rideshare market and the behavior of individuals. Specific behavioral research includes understanding modifications in travel choices influenced by incentives, and responses to changes in variables such as the price of fuel. Some private rideshare providers have indicated a willingness to share their data; similar offers from public agencies would be desirable as well.

3. Many participants saw the integration of rideshare service information with other modal information as essential to improving rideshare participation. A true multi-modal system should give travelers better opportunities to participate in ridesharing.

4. The majority of workshop attendees saw some value in an open-source, common data standard for sharing rideshare data with some participants indicating an interest in working collaboratively its development. However, some participants expressed hesitation about a common standard, given that the technology-enabled rideshare market is still in its infancy. Some business models would rely much more heavily on the interchange of information between providers than others would. Ultimately, the importance of combining rideshare information with other modal information may be the most compelling reason for a common standard and rideshare provider collaboration.

Potential Next Steps:

After some consideration of the common interests expressed at the workshop, three areas of further action are suggested. All three of these topics were discussed at varying levels of detail at the end of the second day of the workshop:

1. Research on Market Size, Travel Behavior: Further research on the potential size of the rideshare market, a better understanding of behavior responses to different incentives and service characteristics, and an understanding of mode choice decisions are all essential. This is perhaps the most pressing action item. Further research will require multiple types of information from a variety of sources. Both academia and rideshare service providers are well suited to take on this task. This requires a willingness on the part of public and private rideshare service providers to share information with the academic community.

2. Development of a Common Data Standard: The development of a common data standard for exchanging rideshare information among providers and for integration with additional modal information is an important task. Open standards for data interchange are very much recommended. Capacity to work on this standard and the technical “know-how” is concentrated in the private sector and, as such, they should continue to lead the effort. Academia may have some role in encouraging participation and collaboration on a common standard among private and public sector rideshare providers. One mechanism that may strongly encourage development of a common standard would be a pilot, demonstration project involving multiple providers and their systems.

3. Design a Rideshare Demonstration Project: The design of a US-based demonstration project using advanced rideshare technologies is a long-term endeavor, but an important step towards proving the potential of technology-enabled ridesharing. This task would require seeking out funding sources for such a trial, spending a significant level of effort on the pre- and post- project evaluation procedures, and including well thought out performance metrics. Consideration of the importance of different stakeholders involved is needed, as is how incentives should be structured to generate the desired changes in behavior.

Main Building Address:
77 Massachusetts Ave
Cambridge, MA 02139
MIT Campus Map

Once you are at 77 Massachusetts Ave:

• Enter through the main doorway (large steps and columns)
• Take the hallway immediately to your right and take the second staircase on the right to the second level
• Turn right at the top of the stairs and you will see the Spofford Room on your left

Room Locations:
Spofford Room, Building #1, Room #236 (1-236)
Building #3, Room #343 (3-343)
MIT Faculty Club, Building E52, 6th Floor

Contact Information:
Andrew Amey, 703-869-3019, amamey@mit.edu
Valerie Webb, 440-339-3296, vwebb@mit.edu

Directions to MIT
Share a Ride:

• Please select a service from the Rideshare Provider Database.
• Desired destination is 77 Massachusetts Avenue

Public Transportation: (From the Airport)

• Take the SilverLine (a Bus Rapid Transit line available outside the terminal near other ground transportation) to South Station
• From South Station, take the Redline Inbound (towards Alewife) to the Kendall/MIT stop
• Once at street level, follow Main St towards the Kendall Hotel (away from the river)
• Left on Vassar St
• Left on Massachusetts Ave, 77 Massachusetts Avenue will be on the left

Public Transportation: (From Amtrak / South Station)

• From South Station, take the Redline Inbound (towards Alewife) to the Kendall/MIT stop
• Once at street level, follow Main St towards the Kendall Hotel (away from the river)
• Left on Vassar St
• Left on Massachusetts Ave, 77 Massachusetts Avenue will be on the left

Taxi:

• Taxi ride will cost somewhere around $25 from the airport, $10-$15 from South Station. Ask to be let out at 77 Massachusetts Avenue

Car: (From the Airport)

• Take Callahan Tunnel from the Airport roadway
• Take MA-1A S to Embankment Rd/MA-28/MA-3/Storrow Drive
• Slight right at Storrow Drive
• Take ramp on left to Harvard Bridge/MA-2A/Massachusetts Ave
• Turn right at Harvard Bridge/MA-2A/Massachusetts Ave
• 77 Massachusetts Avenue will be on the right, just after crossing the river

Parking:

• Please contact Ms. Ginny Siggia at 617-258-8131 if you will need parking and she will email you a permit for a nearby MIT lot.

Map of Nearby Hotels and MIT Workshop Locations

8:00 – 8:30 am: [Spofford Room, Building #1, Room #236 (1-236)]
Continental Breakfast provided by the MIT Real-Time Rides Research Team

8:30 – 10:00 am: [Building #3, Room #343 (3-343)]
Topic 4: Role of Technology Firms in Supporting Wider Rideshare Participation & Providing Multi-Modal Travel Information
[Moderated by Jim Morris]

• 8:30 – 8:45 am: (Damien Balsan, Nokia) – Using NFC Phones to Find, Confirm, and Pay for Rides
• 8:45 – 9:00 am: (Rizwan Khaliq, IBM) – IBM Traffic Prediction and the Provision Traveler Information
• 9:00 – 10:00 am: Feedback and Discussion on Topic 4

10:00 – 10:45 am: [Building #3, Room #343 (3-343)]
Topic 5: Role of Employers, Universities & Other Institutions in Support of Ridesharing
[Moderated by Eric Schreffler]

• 10:00 – 10:15 am: (Charlie Crissman, Goose Networks) – Tradeoffs Between Broad Public Programs and Smaller Closed-Loop Programs
• 10:15 – 10:45 am: Feedback and Discussion on Topic 5

10:45 am – 12:00 pm: [Building #3, Room #343 (3-343)]
Topic 6: Value and Opportunities for a Common Database Feed among Providers
[Moderated by Andrew Amey]

• 10:45 – 11:00 am: (Carl Gorringe, 511.org) - OpenTrip: An Open Protocol for the Interchange of Travel Information Among Rideshare Providers
• 11:00 – 11:15 am: (Harvey Appelbe, Avego) – Extending and Applying Open Protocols to Allow Dynamic Travel to Interoperate
• 11:15 – 12:00 pm: Feedback and Discussion on Topic 6

12:00 – 1:00 pm: [Spofford Room, Building #1, Room #236 (1-236)]
Lunch Provided by the MIT Real-Time Rides Research Team

1:00 – 3:00 pm: [Building #3, Room #343 (3-343)]
Topic 7: Innovative Models for Rideshare Service Provision
[Moderated by Eric Schreffler]

• 1:00 – 1:15 pm: (John Zimmer and Matt Malloy, Zimride and ZipCar) – Joint carshare-rideshare concept
• 1:15 – 1:30 pm: (Amol Brahme, iCarpool) - Integration of Real-Time Ridematching with Traditional Carpool and Vanpool
• 1:30 – 1:45 pm: (Paul Minett, Trip Convergence) - Casual Carpooling as a Model for Real-Time Ridesharing
• 1:45 – 2:00 pm: (Rob Content, Community Solutions) - Social and Community Aspects of Ridesharing
• 2:00 – 3:00 pm: Feedback and Discussion on Topic 7

3:00 – 3:30 pm: [Building #3, Room #343 (3-343)]
Workshop Summary and Follow-up Actions: John Attanucci, Rabi Mishalani, & Jim Morris

Presenter: Michael Messner, Seminole Capital Partners
Title: Ridesharing: NOW is the Time

Presenter: Valerie Webb & Andrew Amey, MIT
Title: Setting the Stage: Common Themes & Rideshare Trends

Presenter: Jim Morris, Carnegie Mellon Silicon Valley
Title: RideFriends: More Rides, Fewer Cars

Presenter: Eric Schreffler, Transportation Consultant (ESTC) & Chair, TRB Policy Section
Title: Real-time Ridesharing: A Historic, Heuristic and sometimes Hysteric Perspective
Abstract: Ridematching has been a backbone of efforts to induce commuters to use alternative modes — in this case, sharing their ride within another traveler. Such programs started with manual ridematching before and during WW II. The advent of ICT (information and communications technology) elevated ridematching by introducing computerized ridematching using DIME files for geo-coding. Today, a new set of products is being forwarded using real-time travel data and PDAs. This offers the potential user powerful and useful information on available shared ride opportunities. However, such systems seem to have found a somewhat limited market in occasional, discretionary trip-making. This is clearly a new market for ridesharing, but one that may not maximize the fulfillment of congestion relief, accessibility, air quality and energy goals. So, the question of “is real-time ridesharing effective or cost effective?”, the answer is, unfortunately, “it depends.”

Presenter: Rick Steele, NuRide
Title: Maintaining Ridesharing During an Economic Downturn
Abstract: Gas prices reached all time highs in the summer of 2008, which resulted in dramatic increases in demand for carpooling. However the party ended abruptly in September 2008 as gas prices tumbled, reaching 5-year lows by the end of 2008. At the same time the U.S. economy entered into a severe downturn resulting in increased unemployment and fewer commuters driving to work. So with record low gas prices, rising unemployment and less traffic due congestion, how do you get commuters interested in ridesharing? NuRide will share the results from a series of initiatives it undertook in Houston to combat these macro-economic conditions.

Presenter: Paul Resnick, Professor - University of Michigan School of Information
Title: Assessing Demand Before There’s a Service
Abstract: How good does a ride matching service have to be in order to be utilized?
The answer is critical for assessing whether services have a chance of being adopted, if marketed effectively. But the answer depends on many factors, including regional and individual differences. In response to generic scenarios, riders and drivers may not be able to accurately predict their own future behavior. I will sketch a proposal for demand estimation based on highly personalized scenarios that ask drivers and riders to reflect on their actual recent travel behavior, as automatically recorded by a mobile device.

Presenter: Susan Squires, Technology Research for Independent Living Centre, Trinity College Dublin
Title: Perceptions of the Private Vehicle in the US: Public Identity vs. Private Space
Abstract: Since at least the 1930s (Blumer 1937) researchers have been fascinated by the place and meaning of the automobile in American culture. Almost all studies, however, have focused on the car as a metaphor for, or symbol of individual expression of self, class and role within the public space (Heffner, Turrentine, Kurai 2006). But what about the automobile’s interior space? Do these meanings apply to the private spaces as well as the public? In 2000, I conduct ethnographic research on the uses and associated meaning of the car’s interior spaces. Using Goffman’s concepts of private and public (1956), this presentation explores the differing meaning of the car as a public statement of identity and a private interior space. Understanding the association of private and car interior has consequences for the meaning, and possible success, of ride sharing.

Presenter: Ted Selker, Carnegie Mellon Silicon Valley
Title: Incentives and Improvements in Lifestyle with Ridesharing
Abstract: People commute in cars, rarely meeting the people next to us that are traveling along almost the same route. The same route can be defined in a ridesharing experience as it was in mine: a commitment to be at the same place and time to go with a specific group. This was difficult for me and others to accomplish. This talk will describe a new paradigm in which people have many reasons to meet with others: social, educational, and for transport. The goal will be to set up an economy of experiences that ridesharing will play into. People will express why they might travel with another and when. The economy will value that and attempt to match the experience with the opportunity. People might travel together to study together, discuss a hobby or childrearing.

Presenter: Kursat Ozenc, PhD Student – Carnegie Mellon University
Title: SafeRide: Alternative Ways of Commuting
Abstract: A national survey found that 76% of the working population in United States drives to work by themselves. On average, it takes people 30-40 minutes each way to travel to work. For some people commuting time is an isolated time of the day, blended with stress and anxiety. For others it is an opportunity to relax, and transition between their work and family roles. The goal of this project is to understand both the positive and negative aspects of commuting, and to design a ridesharing service concept that will leverage technology to overcome obstacles that such services have traditionally encountered. We conducted semi-structured interviews with thirty commuters in the Carnegie Mellon University community, including solo drivers, carpoolers and bus riders. We observed that convenience, cost and personal preferences motivate commuting choices. Commuters who talked about convenience were primarily interested in commuting options that allowed them to maintain a flexible schedule. Commuters who talked about cost talked about both time and money spent on commuting. Commuters who talked about personal preferences often mentioned preferences regarding conversation during their commute. Once commuters establish a routine, they tend to continue commuting using their chosen method. We are currently working on design concepts that leverage insights gained from these interviews. We plan to evaluate these design concepts with people who are currently casual carpooling in the Bay area.

Presenter: Allen Greenberg, FHWA
Title: Lessons Learned about Real-time Ridesharing and Governmental Considerations for Future Support
Abstract: Real-time ridesharing tests have mostly, but not always failed and lessons can be drawn from both successful and failed efforts. The potential benefits of real-time ridesharing are enormous, including enhanced affordable mobility and reduced vehicle-miles traveled, leading to congestion and emissions reductions and infrastructure-cost savings. It is because of these potential benefits that governmental support of dynamic ridesharing may be attracted. Projects proposed for such support must take lessons from previous and on-going effort to heart (including from the successes of casual carpooling) in order to receive favorable consideration.

Presenter: Kay Carson, MassRides / Massachusetts Executive Office of Transportation
Title: Massachusetts: A Statewide Approach to Ride-Sharing
Abstract: The presentation will include a short history of ridesharing in Massachusetts over the past few decades followed by a description of the state’s approach to staffing, marketing, and tools (e.g. phone support, active website, etc.) It will conclude with a discussion of what Massachusetts is looking forward to expand and improve its ride-matching program.

Friday, April 17, 2009

Presenter: Damien Balsan, Nokia
Title: Using NFC Phones to Find, Confirm, and Pay for Rides
Abstract: [Abstract Pending]

Presenter: Rizwan Khaliq, IBM
Title: IBM Traffic Prediction and the Provision Traveler Information
Abstract: The presentation start with a high level overview of IBM’s current Intelligent Transportation Systems (ITS) work, and will follow with a demonstration of the IBM Traffic Prediction solution. This solution is currently in use in Singapore and allows for the prediction of where traffic will occur, prior it to it happening. With the ability to predict events such as heavy traffic congestion and communicate that information to travelers prior to its occurrence, travelers may make more informed choices regarding their mode of travel.

Presenter: Charlie Crissman, Goose Networks
Title: Tradeoffs Between Broad Public Programs and Smaller Closed-Loop Programs
Abstract: [Abstract Pending]

Presenter: Carl Gorringe, 511.org Rideshare / Gotalift
Title: OpenTrip: An Open Protocol for the Interchange of Travel Information Among Rideshare Providers
Abstract: This talk will introduce OpenTrip, an open XML data format for exchanging trip data, and a brief look at an example at www.opentrip.info. It will open with a round-table discussion on how we can improve collaboration, why we should use a common data format, how to encourage implementation, and what should be our next steps moving forward. If there is interest, there can also be discussion on the technical details of the current specification.

Presenter: Harvey Applebe, Avego
Title: Extending and Applying Open Protocols to Allow Dynamic Travel to Interoperate
Abstract: This presentation will discuss how to extend protocols to allow many transport modes, such as taxi, shuttle bus, van pool, hourly car rental, scheduled transport (trains, bus), dynamic ride sharing to interoperate, in real-time. It will propose a superstructure that allows interoperable services to register and discover other services.

Presenter: John Zimmer and Matt Malloy, Zimride and Zipcar
Title: Joint Rideshare-Carshare Concept
Abstract: In an era in which increasing numbers of people are turning to the Web and their social networks as the primary way of communicating, organizing their day and planning events, it’s more important than ever to connect our physical world with the virtual world. Zipcar leverages Web, wireless and hardware technologies to make reserving and using a car by the hour as easy as getting cash from an ATM. Zimride leverages the power of social networks, consumer ratings/rankings and Web 2.0 to make finding and sharing a ride a snap. Together, they allow people to build friendships, share experiences, save money and reduce emissions. As leaders in their respective markets, car sharing and ridesharing, Zipcar and Zimride are well poised to co-present current and future ridesharing trends.

Presenter: Amol Brahme, iCarpool – Representing RideShare Online
Title: Integration of Real-Time Ridematching with Traditional Carpool and Vanpool
Abstract: In 1991, Washington State passed a law called the Commute Trip Reduction Law that has shaped transportation demand management programs in the state for the past 17 years. It has driven the development of innovative programs that support reduction in drive alone commuting at the county, city and employer levels. One of these programs RideshareOnline.com, is planning to implement the next generation of ridematch technology in 2009 in the tri-state area of the Pacific Northwest encompassing Washington, Oregon and Idaho.

With the advent of newer technology such as smart phones and SMS, dynamic carpool (also known as real time ridematching) is seeing increased interest from employers, agencies and the public because it provides much needed flexibility which is not found in traditional carpool/vanpool. The presentation compares dynamic carpool with traditional carpool and vanpool in terms of merits and demerits of each. The presentation also covers why neither traditional carpool nor dynamic carpool can solve the user’s needs by itself. The approach taken by RideshareOnline.com is to integrate dynamic carpool trips with traditional carpool trips to increase the potential pool of available matches for both types of trips.

Presenter: Paul Minett, Trip Convergence Ltd
Title: Casual Carpooling as a Model for Real-Time Ridesharing
Abstract: TCL has developed flexible carpooling, a system that builds on casual carpooling and slugging. We will present information about:

Casual car pooling is probably the most effective system of real time ridesharing in existence, accounting for as many as 13,000 rides each day with no pre-arrangement, in 6,500 single use, three person car pools. We will explain why we believe that for increased car pooling the authorities should provide meeting places, not databases.

Presenter: Rob Content, Community Solutions
Title: The Smart Jitney: Rapid, Realistic Transportation Reinvention
Abstract: The Smart Jitney is a system of efficient and convenient ride sharing that addresses in the short-term the problem of transportation in a post-peak oil world. The system utilizes the existing infrastructure of private automobiles and roads due to the time, expense, and difficulty of building a new transportation infrastructure amongst such a dispersed population. The Smart Jitney system would use cell phones and the Internet for ride reservations and coordination. Riders and drivers would have modified cell phones with a GPS function. The goal of the system is to insure that each private car always carries more than one person per car trip, optimally 4-6. This would cut auto gasoline usage by an estimated 80 percent and commute time by an average of 50 percent within two years.

9:30 – 10:00 am: [Spofford Room, Building #1, Room #236 (1-236)]
Registration/Continental Breakfast provided by the MIT Real-Time Rides Research Team

10:00 – 10:30 am: [Building #3, Room #343 (3-343)]
Introduction: John Attanucci (MIT) and Michael Messner (Seminole Capital Partners)

• Introduction of Organizers
• Introduction of Participants
• Workshop Charge and Goals

10:30 – 11:00 am: [Building #3, Room #343 (3-343)]
Setting the Stage: Past and Present Rideshare Markets

• 10:30 – 10:45 am: (Andrew Amey and Valerie Webb, MIT) – Statistics and Historical Trends
• 10:45 – 11:00 am: (Jim Morris, CMU West) – RideFriends: More Rides, Fewer Cars

11:00 am – 12:30 pm: [Building #3, Room #343 (3-343)]
Topic 1: Historical Ridesharing Trends and Market Potential
[Moderated By Jim Morris]

• 11:00 – 11:15 am: (Eric Schreffler, Consultant) – Real-time Ridesharing: A Historic, Heuristic and sometimes Hysteric Perspective
• 11:15 – 11:30 am: (Rick Steele, NuRide) – Maintaining Ridesharing During an Economic Downturn
• 11:30 – 11:45 am: (Paul Resnick, University of Michigan) – Assessing Demand Before There’s a Service
• 11:45 – 12:30 pm: Feedback and Discussion on Topic 1

12:30 – 1:45 pm: [Spofford Room, Building #1, Room #236 (1-236)]
Lunch Provided by the MIT Real-Time Rides Research Team, Walk to MIT Faculty Club

1:45 – 3:15 pm: [MIT Faculty Club, Building E52, 6th Floor]
Topic 2: Behavioral and Attitudinal Characteristics of Travelers - Role of Incentives and How to Overcome Safety and Security Concerns
[Moderated by Rabi Mishalani]

• 1:45 – 2:00 pm: (Susan Squires, Trinity College) – Perceptions of the Private Vehicle in the US: Public Identity vs. Private Space
• 2:00 – 2:15 pm: (Ted Selker, CMU West) - Incentives and Improvements in Lifestyle with Ridesharing
• 2:15 – 2:30 pm: (Kursat Ozenc, CMU) – Saferide: Alternative Ways of Commuting
• 2:30 – 3:15 pm: Feedback and Discussion on Topic 2

3:15 – 4:15 pm: [MIT Faculty Club, Building E52, 6th Floor]
Topic 3: Role of Different Levels of Government in Support of Ridesharing
[Moderated by John Attanucci]

• 3:15 – 3:30 pm: (Allen Greenberg, FHWA) - Lessons Learned about Real-time Ridesharing and Governmental Considerations for Future Support
• 3:30 – 3:45 pm: (Kay Carson, MassRides / Massachusetts EOT) Massachusetts: A Statewide Approach to Ride-Sharing
• 3:45 – 4:15 pm: Feedback and Discussion on Topic 3

4:15 – 6:00 pm: [MIT Faculty Club, Building E52, 6th Floor]
Service Provider Presentations on history of their company, interest in ridesharing, demonstration of their product, and vision of the future

6:00 – 6:45 pm: [MIT Faculty Club, Building E52, 6th Floor]
First Day Wrap-up & Pre-Dinner Drinks

6:45 pm: [MIT Faculty Club, Building E52, 6th Floor]
Dinner at the MIT Faculty Club provided by the Real-Time Rides Research Team

1. Carl Gorringe, 511.org Rideshare / Gotalift
   
2. Harvey Appelbe, Avego by Mapflow
   
3. Jason Conley, Avego by Mapflow
   
4. Marianne Tyrrell, British Consulate-General - Science and Innovation Team
   
5. Neelangi Gunasekera, British Consulate-General - Science and Innovation Team
   
6. Jim Gascoigne, Charles River Transportation Management Association
   
7. Ted Selker, Prof - Carnegie Mellon Silicon Valley, Associate Director of Mobility Research
   
8. Kursat Ozenc, PhD Student - Carnegie Mellon University
   
9. Steffen Frost, Carticipate
   
10. Darius Roberts, Carticipate
    
11. Ross Edgar, CommuterConnections
    
12. Stephen Finafrock, CommuterConnections
    
13. Allen Greenberg, Federal Highway Administration
    
14. Antoine Averseng, French Embassy (US) - Trade Office
    
15. Robin Chase and/or Mark Chase, GoLoco
    
16. Roy Russell, GoLoco
    
17. Charlie Crissman, Goose Networks
    
18. Rizwan Khaliq, IBM - Intelligent Transportation Systems & Emerging Markets
    
19. Amol Brahme, iCarpool
    
20. David Grennan, Independent Consultant - Ireland
    
21. Kay Carson, MassRides
    
22. Leon Papadopolous, MassRides
    
23. Larry Brutti, MIT Parking & Transportation Office
    
24. Rob Content, Morgan Institute for Community Solutions
    
25. Damien Balsan, Nokia
    
26. Rick Steele, NuRide
    
27. [Potential Representative], PickupPal
    
28. Jeffrey Chernick, RideAmigos
    
29. Michael Messner, Seminole Capital Partners
    
30. Susan Squires, Technology Research for Independent Living Centre, Trinity College Dublin
    
31. Eric Schreffler, Transportation Consultant (ESTC) & Chair, TRB Policy Section
    
32. Paul Minett, Trip Convergence, Ltd.
    
33. Kristin Lovejoy, PhD Student - University of California, Davis
    
34. Paul Resnick, Prof - University of Michigan
    
35. Holly Parker, Yale University
    
36. John Zimmer, ZimRide
    
37. Matt Malloy, Zipcar
    

MIT / CMU Rideshare Research Team (5):

1. Jim Morris, Carnegie Mellon Silicon Valley
   
2. John Attanucci, MIT Rideshare Research
   
3. Rabi Mishalani, Ohio State University
   
4. Andrew Amey, MIT Rideshare Research
   
5. Valerie Webb, MIT Rideshare Research

1. Ridesharing has a strong cultural and social aspect to it. The largest group of ridesharers are family members or related individuals. The rideshare mode split among the Hispanic population is nearly twice the US average, but declines rapidly with increasing residency.

2. The strongest indicators of rideshare use in the US appear to be income and, to a lesser extent, congestion. Rideshare participation decreases rapidly with increasing income. Only the Seattle metro area has a relatively consistent rideshare mode split across income groups. Rideshare appears to be higher in metro areas with greater congestion, although the trend is much more pronounced in large and very large metro areas.

3. At an aggregate level, rideshare participation appears to be higher in low density metropolitan areas, but the reasons for this are not entirely clear. Intuitively, ridesharing requires at least some density of riders with similar origins and destinations in order to work. However, higher densities are often accompanied by larger and more interconnected transit systems that may compete for rideshare participants. For lower density metropolitan areas, ridesharing may function as a type of small vehicle transit.

4. It is not clear whether ridesharing and transit are complements or substitutes. The international analysis of transit share and rideshare participation shows a potential substitution between the two modes, however the metropolitan analysis did not show any significant trade-off between transit share and ridesharing in the US context. Anecdotally, there is evidence from San Francisco that people who choose to rideshare previously rode transit, suggesting that the two modes are substitutes. On the opposite side, evidence from Seattle and San Francisco suggests that when passengers cannot find an appropriate ride-match, they rely on transit services to reach their desired destination, suggesting that the two modes are complementary.

However, occupancy for different trip purposes is only one aspect of capacity utilization; one must also consider differing trip lengths by trip purpose. The following chart shows total annual seat miles of unused capacity per vehicle for different trip types. Nearly half of all unused capacity is for commute or work related trips. This reinforces the previous belief that ridesharing initiatives should focus on commute-based trips. One should also consider the differing values of time that users place on different trip types. Commute trips are likely to have a higher value of time for most drivers, thereby making any inconvenience or delay in their journey increadibly onerous. If ridesharing is to be improved during the commute, convenience for drivers and passengers, and minimal delays are essential.