U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590

Skip to content
Facebook iconYouTube iconTwitter iconFlickr iconLinkedInInstagram

Federal Highway Administration Research and Technology
Coordinating, Developing, and Delivering Highway Transportation Innovations

This report is an archived publication and may contain dated technical, contact, and link information
Back to Publication List        
Publication Number:  FHWA-HRT-13-053    Date:  May 2013
Publication Number: FHWA-HRT-13-053
Date: May 2013


Exploratory Advanced Research Program

Casual Carpooling Focus Group Study

PDF Version (1.86 MB)

PDF files can be viewed with the Acrobat® Reader®

HTML Version of Errata for FHWA-HRT-13-053

PDF Version of Errata (1.17 MB)


As of June 2013, this online document was modified in the following ways:

Editorial corrections were made to this report after the report was originally published. The following table shows the modifications that were made to this report.

Location Correction URL
Page i, Box 15 Add:"Department of the Navy Technical Contact: Marc Oliphant" https://www.fhwa.dot.gov/advancedresearch/pubs/13053/index.cfm#errata01
Page 1 Change: Casual Carpooling Scan Report and Appendix B to the Casual Carpooling Scan Report to: Casual Carpooling Scan Report and Appendix B to the Casual Carpooling Scan Report https://www.fhwa.dot.gov/advancedresearch/pubs/13053/001.cfm#errata02
Page 5 Change sentence to: "As shown in figure 1, casual carpooling occurs in the…” https://www.fhwa.dot.gov/advancedresearch/pubs/13053/002.cfm#errata03
Page 15, Table 3 Add: “No Response” to blank cell. https://www.fhwa.dot.gov/advancedresearch/pubs/13053/002.cfm#errata04



This report describes the results of a focus group study that explored the phenomenon of casual carpooling from the perspective of individuals who participate in such systems as drivers and/or passengers. Focus groups were held in three of the largest and longest running casual carpooling systems in the Nation: Washington, DC; Houston, TX; and San Francisco, CA. This study was conducted in tandem with a scan trip evaluation conducted in November and December 2010, which brought together a group of academics and transportation professionals to explore the mechanics, logistics, and success of the practice by visiting casual carpooling lines and observing and comparing practices among the three locations. Together, the findings and conclusions drawn from the focus group study and scan trip evaluation will be used to identify possible future research on the potential for and value of expansion or replication of casual carpooling.

Robert E. Arnold
Director, Office of Transportation
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

Casual Carpooling Focus Group Study

5. Report Date

May 2013

6. Performing Organization Code
7. Author(s)

Mia Zmud and Claudia Rojo

8. Performing Organization Report No.


9. Performing Organization Name and Address

NuStats LLC
206 Wild Basin Road, A-300
Austin, Texas 78746

10. Work Unit No. (TRAIS)

11. Contract or Grant No.

GS-10F01072N; DTFH61-10-F-00088

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

Final Report, September 2010 to March 2013

14. Sponsoring Agency Code


15. Supplementary Notes

FHWA's Contracting Officer's Technical Representative (COTR): Zachary Ellis, HRTM-30
FHWA Technical Contact: Allen Greenberg
Department of the Navy Technical Contact: Marc Oliphant

16. Abstract

Qualitative research in the form of focus groups was conducted from June 2012 through September 2012 to explore the phenomenon of casual carpooling (also called slugging, informal carpooling, and dynamic ridesharing). Eight focus groups were held in three regions with the largest and longest running casual carpooling systems in the Nation: Washington, DC; Houston, TX; and San Francisco, CA. At each location, the focus groups were held with drivers and passengers who are active participants in casual carpooling. The focus groups took place over 1 to 2 days on separate evenings with generally one or two groups being held each evening (one focus group in Washington, DC, was held midday). A total of 83 individuals participated in the focus groups.


With the goal of enriching understanding of casual carpooling systems from the participants’ perspective, this effort provided insights, results, and conclusions to the following research questions:


1. What are the underlying social-cultural dynamics that comprise the casual carpooling system?
2. What are the factors that attract participants to casual carpooling and influencers that motivate them to stick with the system?
3. What are the opportunities for system improvements that may improve the casual carpooling experience?

17. Key Words

alternative commuting, casual carpooling, dynamic ridesharing, carpooling, electronic slugging, slugging, slugs, flexible carpooling, informal carpools, ride matching, ridesharing, ridesharing systems.

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

AMENDED June 3, 2013


SI* (Modern Metric) Conversion Factors


Table of Contents












List of Figures

Figure 1. Map. Casual carpooling locations in the Washington, DC, region

Figure 2. Map. Park-and-ride locations in the Houston, TX, region

Figure 3. Map. Casual carpooling locations in the San Francisco, CA, region

Figure 4. Illustration. Example of the study's invitation to participate in the focus groups


List of Tables

Table 1. Participant summary (Washington, DC, region)

Table 2. Participant summary (Houston, TX, region)

Table 3. Participant summary (San Francisco, CA, region)

Table 4. Characteristics by study region


Federal Highway Administration | 1200 New Jersey Avenue, SE | Washington, DC 20590 | 202-366-4000
Turner-Fairbank Highway Research Center | 6300 Georgetown Pike | McLean, VA | 22101