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Publication Number:  FHWA-HRT-13-023    Date:  November 2012
Publication Number: FHWA-HRT-13-023
Date: November 2012


Appendix B to The Casual Carpooling Scan Report

Washington, DC; Houston, TX; and San Francisco, CA

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The Federal Highway Administration’s (FHWA’s) Exploratory Advanced Research (EAR) Program addresses the need to conduct longer term and higher risk breakthrough research with the potential for transformational improvements to plan, build, renew, and operate safe, congestion free, and environmentally sound transportation systems. The program addresses underlying gaps faced by applied highway research programs, anticipates emerging issues with national implications, and reflects broad transportation industry goals and objectives.

During November and December 2010, the EAR Program supported a team that consisted of transportation professionals, academic faculty, and business entrepreneurs who visited informal carpool lines (also called slug lines or casual carpool lines) in Washington, DC; Houston, TX; and San Francisco, CA, to observe “slugs” and to compare practices among locations. The team also met with private ride–match providers, regional planners, carpool participants, and transportation planners and engineers, with the overall goal of studying these ridesharing systems to evaluate whether to fund research on the potential for and value of expansion or replication. The observations of the individual scan members at each slug line location are included in this appendix.

Robert E. Arnold
Director, Office of Transportation Management

Debra S. Elston
Director, Office of Corporate Research,
Technology, and Innovation Management


This document is disseminated under the sponsorship of the U.S. Department of Transportation in the interest of information exchange. The U.S. Government assumes no liability for the use of the information contained in this document.

The U.S. Government does not endorse products or manufacturers. Trademarks or manufacturers’ names appear in this report only because they are considered essential to the objective of the document.

Quality Assurance Statement

The Federal Highway Administration (FHWA) provides high-quality information to serve Government, industry, and the public in a manner that promotes public understanding. Standards and policies are used to ensure and maximize the quality, objectivity, utility, and integrity of its information. FHWA periodically reviews quality issues and adjusts its programs and processes to ensure continuous quality improvement.


Technical Report Documentation Page

1. Report No.


2. Government Accession No. 3 Recipient's Catalog No.
4. Title and Subtitle

Appendix B to the Casual Carpooling Scan Report

5. Report Date

November 2012

6. Performing Organization Code
7. Author(s)

M. Burris, E. Christopher, P. DeCorla-Souza, A. Greenberg,
S. Heinrich, J. Morris, M. Oliphant, E. Schreffler, P. Valk, P. Winters

8. Performing Organization Report No.


9. Performing Organization Name and Address

Office of Transportation Management
Congestion Management and Pricing Team
Federal Highway Administration
1200 New Jersey Ave., SE
Washington, DC 20590

10. Work Unit No. (TRAIS)

11. Contract or Grant No.
12. Sponsoring Agency Name and Address

Office of Corporate Research, Technology, and Innovation Management
Federal Highway Administration
6300 Georgetown Pike
McLean, VA 22101-2296

13. Type of Report and Period Covered

Scan Report, November 17–December 8, 2010

14. Sponsoring Agency Code


15. Supplementary Notes

FHWA’s Contracting Officer’s Task Manager (COTM): Zachary Ellis, HRTM-30

16. Abstract

During November and December 2010, the Exploratory Advanced Research (EAR) Program supported a team that consisted of transportation professionals, academic faculty, and business entrepreneurs who visited informal carpool lines (also called slug lines or casual carpool lines) in Washington, DC; Houston, TX; and San Francisco, CA, to observe “slugs” and to compare practices among locations. The team also met with private ride–match providers, regional planners, carpool participants, and transportation planners and engineers with the overall goal of studying these ridesharing systems. This appendix provides the personal observations of the scan members at each of the three slug line locations. The full report is published as FHWA-HRT-12-053, Casual Carpooling Scan Report.

17. Key Words

Alternative Commuting, Carpooling, Casual Carpooling, Dynamic Ridesharing, Electronic Slugging, Flexible Carpooling, Informal Carpools, Ride Matching, Ridesharing, Ridesharing Systems, Slugging, Slugs.

18. Distribution Statement

No restrictions. This document is available to the public through the National Technical Information Service, Springfield, VA 22161.

19. Security Classification
(of this report)


20. Security Classification
(of this page)


21. No. of Pages


22. Price


Form DOT F 1700.7 (8-72) Reproduction of completed page authorized

Table of Contents

Appendix B: Personal Observations from Scan Participants

About the Exploratory Advanced Research Program

Appendix B: Personal Observations from Scan Participants

Washington, DC

Jim Morris

I am interested in seeking ways smart phones could help several people who said they look for particular people to ride with. I have been thinking of a rendezvous application (app) that people could use during short windows of time to find specific people. This app would be much more specialized than Google Latitude or Facebook Places applications.

Many of us heard that word-of-mouth was the most common way for people to be introduced to slugging, but we are looking at a fully mature system. The billion-dollar question (for would-be viral apps) is how one gets such a dynamic ridesharing program started. Slugging in DC began before the Web and had a long time to climb the exponential curve. How or what would we use today in a place where it doesn't exist?

The looming question, “What can cell phones do to help promote ridesharing?,” is still unanswered. Even AVEGO says it will take years to arrive at a good answer. In the meantime, I'm going to create a simple app called “Meet Me” or “The Chaperone” that slugs could use to coordinate linking up with their preferred partners. It would start with one person starting the app and designating who they want to meet with. Anyone else running the app would receive the message. If they agree to meet, the app would then track their two (or more) locations and estimate the time and place of meeting. Another suggestion would be a Twitter account for each line that describes the current state of the line for people deciding whether to go to a rideshare location.

Marc Oliphant

Peter Valk

Replicating slugging will be a challenge, because it has evolved from a very specific need and was cultured in an environment with the right conditions (see Phil’s and Eric’s comments). It will be interesting to see how the conditions and processes for slugging in Houston, TX, and San Francisco, CA, compare with Washington, DC. I think there may be an opportunity for slugging to emerge in regions where tolling will be introduced; the toll will be significant enough to change travel behavior. There are HOV lanes (3+ will be much easier, but 2+ may work), and there are few other roadways to choose from when making trips.

Slugs felt that the presence of transit service at both ends of the trip was essential, because many used it on days when the weather was inclement. Slugs do not consider themselves carpoolers and would unlikely participate in a more structured carpool because of schedule constraints (i.e., slugging does not require communicating with others on how you will be traveling compared with carpools and certainly vanpools).

I recognize the potential value of developing slugging guidelines (as suggested by Phil) but am challenged about how guidance can be introduced without compromising the organic nature that seems to be at the heart of slugging’s success;  folks seem to be able to work things out without much guidance. I may be reading more into the tone of our conversations with slugs, but there appears to be an appreciation for how slugging has developed on its own. The trick for planners is to determine how slugging can be sparked where it best seems to make sense without damaging the informal evolutionary development.

I think that the best chance of creating new slugging opportunities (in communities with no slugging history and no HOV 3+ lanes) will be to work with a large employer (where workers have an established association) that is looking to mitigate the effects of new tolls or to reduce SOV use. The employer would have the means to provide a catalyst of informal action amongst a core group and to facilitate initial slugging (e.g., create digital communication channels and identify onsite slugging locations).

Eric Schreffler

Phil Winters

Base Realignment and Closure (BRAC) Commission:

Additional observations:

Allen Greenberg

November 18, 2010: Telegraph Road–Woodbridge Slug Line

November 19, 2010: Slugging/BRAC Meeting with Peggy Tadej

Six-thousand four-hundred employees will be moving from Crystal City to the transit-inaccessible Mark Center. There has already been made available $7.5 million for nearby transportation improvements. By comparison, 23,000 employees work at the Pentagon, 26,400 at Fort Belvoir (13,300 new employees) plus 8,500 employees at the nearby Engineering Proving Ground (all new), and 19,000 at Quantico (2,700 new). Work location moves are inspired by security needs. Each Federal employee also brings contractors. There is reduced parking at all BRAC-affected facilities. Each department or agency gets an allotment of parking spaces, and reverse commutes do not have HOV lanes. Fort Belvoir and Quantico are situated in remote locations, relatively far from Washington, DC.

Houston, TX

Marc Oliphant

Mark Burris

At the Northwest Station, there was a steady stream of cars and people during the time I was there (from about 8 to 8:30 a.m.). The HOV-3+ time period had just ended, so most drivers (maybe all while I was there) were picking up just one passenger. The line of slugs was never more than four passengers long.

The driver that I rode with decides at the last second on a day-to-day basis whether he will pick up a slug. His drive to the Northwest Freeway gives him a glimpse of traffic on the freeway. If it looks bad, he heads for the park-and-ride lot to pick up a slug. If he leaves late (like he did on the day I rode with him), then it is a very high probability he will pick up someone. If he leaves early (say, 6:30 a.m.) then the odds are lower that he will pick up someone.

Another driver uses the slug line, mainly because the building where he works is the last in a series of stops for the bus (meaning he can avoid having to endure all the bus stops).

Jim Morris

Slugging is pretty sensitive to the conditions. In Houston, TX, an improvement to a highway that reduced congestion reduced slugging by 50 percent. In addition, very few people slugged home at night. The only explanation seems to be the uncertainty of destination.

A few days after I returned to Pittsburgh, PA, I had an informal interview with a woman in my downtown apartment building. She moved from an outlying suburb because she could not stand the 1.5-hour bus commute. When I explained my thoughts about opening a busway to carpools, she said it would work and that it would have kept her from moving. She would drive to her local park-and-ride lot, park or drive depending on the relative queue lengths, avoid the meandering bus to the busway, and avoid standing in the standing-room-only bus from there. She said the busway has plenty of space for cars, both widthwise and headroom-wise. A difficult issue she raised is the racial mix. She said that the small number of whites who wait for the bus appear uncomfortable; slugging might help increase the comfort level, although some passengers may initially be impeded by general fear. She also reported that there is surplus parking at the bus stop entering the busway. I rode the busway one day to verify all this. It is one lane in each direction with cut outs for stops. The bus drivers I asked did not like the idea, of course; they are believed to be the highest paid drivers in the country.

Opening a busway seems obvious: previous cutbacks in service have made the buses too crowded and the busway pavement more open. However, I fear I am about to learn what you all know: there will be many financial and political impediments to making this change.

Susan Heinrich

At the Addicks Park-and-Ride lot, the woman I rode with said she usually likes to take two people because she feels safer, even though she only needs one person to use the HOV lanes. She said she made an exception with me because I was a female passenger. She does not pick up passengers every day, but does it regularly. She does not ever ride—just drives—because she likes to have her car. In most cases she picks up riders to save time, but she likes saving money, too. It “gets tiring” paying so much in tolls. The driver makes the riders listen to her music, jokingly commenting that the people in the back seat have to listen to her music more loudly. The main “wow factor” for me was how significant the park-and-ride lots are and how they provide such easy on-and-off access to the freeways.

Phil Winters

In terms of safety, although there was a security booth onsite, it was unmanned. Cameras with anomaly detectors were used, which were alerted to people wandering through the lot. There were locked gates after rush hour, and one would need a transit pass to access the lot even if carpooling from the lot.

Four-minute headways mean that slugs may have to wait longer to be picked up, but they also avoid the $4.50-per-trip bus ride. The bulk discount for bus rides is only 55 trips for the price of 50. As a result, cost savings was a main issue in terms of choosing to rideshare. Trips back to the original destination were referenced by bus number (park and ride). Both the driver and rider knew other drivers and exchanged experiences. All slugs were friendly and willing to talk. The outstanding question is whether managed lanes increase people throughput (not vehicle).

METRO reps seem to think of slugs as “others” rather than what they are—part-time transit users. I find that view troublesome for expanding the concept of slugging. METRO reps (and others) seem to think plausible deniability is a good strategy (seems like a de facto rather than a deliberated strategy). It is unclear if they view slugging as a means to shave the number of travelers during peak demand times. Increased ridesharing may not be able to reduce the number of bus drivers because of labor unions. This might be a good topic for research.

I think focus groups might want to include transit riders who use the same park-and-ride lots as slugs. There may be people who tried slugging and stopped or those who refused to try it at all (e.g., if an employer pays for transit costs).

Ed Christopher

As everyone knows, for me, the highlight was getting into a vehicle with heated seats on a cold morning. Our driver was a dedicated driver and is never a passenger. However, many years ago (two jobs ago), she started out as a passenger when solicited at a bus stop. She has been doing the carpool thing (driving) for several years. I did not get the sense that she was doing it for the cost or time savings. Although it is hard to prove, I would bet that she is doing it more for the social experience. She lived by the lot and had to pass by it on her way to work. She also had other friends who are drivers, and they talk to each other about their carpool experiences. She never does the carpool thing on the way home.

My wow factor from Houston was that everyone I talked with had been involved with organized hitchhiking (I dislike the term slugging) for many years. I am sure that there are new entrants to the market, but based on my anecdotal evidence, 8 years was the average time span of participation. In addition, although Phil makes a good point about the carpoolers being part-time transit customers, I was very surprised that METRO “turned their head” and let the passengers park in their lots for free. What really surprised me is that parking was free for everyone. Come to think about it, my driver said that she had free downtown parking as well.

Peter Valk

I concur with Phil’s and Ed’s observation about METRO’s failure to recognize that commuter carpoolers are tax-paying citizens who have rights to use their facilities. I think commuter carpoolers will be moved off the park-and-ride lots if and when parking facilities reach capacity.

I think there are sufficient grounds, based on findings from our visits, to pursue a pilot project that seeks to catalyze ridesharing. We know that ridesharing can grow to where there are HOV-3+ lanes, reduced tolls, and back-up transit service. There are few circumstances like this. The challenge is to determine whether ridesharing could be successful in HOV-2+ conditions in which there is variable tolling with pricey peak fees. The key is how to initiate the spark and stimulate its natural growth.

I am inspired by how ridesharing has flourished without any government intervention and without a “technology” solution—a breath of fresh air.

Allen Greenberg

Rides to Commuter Destinations

Reverse Ride Home

San Francisco, CA

Marc Oliphant

North Berkeley BART

Grand and Lakeview Morning Line

Mark Burris

Jim Morris

Slugging is pretty sensitive to the conditions. In San Francisco, the transit authority put up signs to sort out the home-bound slugs and induced a rather robust evening slug culture, even though there is no toll on the Bay Bridge. It is still very sensitive, though: nobody will take you from San Francisco to the North Berkeley BART station, but they will take you about 16 km (10 mi) north to another station. It is all about of the length of the HOV path.

Susan Heinrich

The San Francisco Bay Area does not have the luxury of providing park-and-ride lots designed to provide easy on-and-off access to the freeways like Houston does, but if it did, I would think that casual carpooling would be more inclined to take off along corridors other than the Bay Bridge corridor.

Phil Winters

My first driver was driving his daughter to school. He did not pick up riders on the reverse trip because he often worked late. My other driver was a construction worker who drove a van with one seat and a cracked windshield. He carpooled for the time savings and to help others in a tough economy. This was the first time I heard anyone talk about altruistic motives being part of the equation.

No participants could think of how a technology application could improve the situation.

Ed Christopher

San Francisco was interesting, yet far different compared with the other cities. Both my drivers had free downtown parking through their employers. My driver on the first day has been carpooling since the 1970s and had even participated in the early ride-matching service. Although we offered money, it was like we had to force it on him. He said that he did not do it for the money. I got the sense he was very liberal and was carpooling for the time savings and the “doing his part for the environment” thing. He drove all the time when he carpooled but rode his bike to work most of the time. Driving was just something he did maybe 2 days a week.

My driver the second day was a woman who had been carpooling for only a few months. She had just moved from Orange County (Los Angeles, CA, region), and her daughter told her about casual carpooling. She was most certainly doing it for the time savings. She, too, had free parking and never drove anyone home on the return trip. I would put her age in the early fifties.

My ride out of North Berkley was not notable except for trying to get a picture of a violator in front of us. It looked like violating was the norm. I was also struck by the change in demographics. For both of my inbound trips, I would say that my drivers were “doing well” in terms of income. For my trip home, in regard to both the other passenger and the driver, I would put them in much lower economic strata. Although I can understand why people would want to be passengers, I could not figure out why my driver bothered to pick anyone up. There was a small time savings, but some empirical work would need to be done to determine whether the time savings erodes away when dropping people off. I could not ask the driver as I do not think he spoke English.

Dinner with Betty was great, and having her empirical evidence temper our anecdotal evidence was a real plus.

Peter Valk

I was impressed with how the City of San Francisco supports casual carpooling. San Francisco realizes that it is a legitimate means of commuting and has not shirked from its responsibility to provide a safe place for commuters to queue for rides home.

Allen Greenberg

North Berkeley BART Lot

Return from San Francisco

About the Exploratory Advanced Research Program

FHWA's Exploratory Advanced Research (EAR) Program focuses on long-term, high-risk research with a high payoff potential. The program addresses underlying gaps faced by applied highway research programs, anticipates emerging issues with national implications, and reflects broad transportation industry goals and objectives.

To learn more about the EAR Program, visit the EAR Web site at www.fhwa.dot.gov/advancedresearch. The site features information on research solicitations, updates on ongoing research, links to published materials, summaries of past EAR Program events, and details on upcoming events.

For additional information, contact David Kuehn, FHWA, 202-493-3414 (email: david.kuehn@dot.gov); or Terry Halkyard, FHWA, 202-493-3467 (email: terry.halkyard@dot.gov); or Zachary Ellis, FHWA, 202-493-3193 (email: zachary.ellis@dot.gov).


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