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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

METHODOLOGY

 

Research Design

The research approach selected for this study was qualitative research in the format of focus groups. This section describes the key design elements of the study including the limitations associated with qualitative research and the use of its findings.

Framework

General research design and the methods used to implement that design should flow naturally from an underlying conceptual model or framework. Our framework posits that system factors, individual factors, and environmental factors influence the outcome behavior of casual carpooling. System factors include the naturally occurring nature of the system, employer–based programs that support ridesharing, or other institutional factors that contribute directly or indirectly to the system. Individual factors include social identity, individual expression, culture, social bonding, attitudes and beliefs, and personal values. Environmental factors include community characteristics, such as geographic location, prevalence of transit, HOV and other managed lanes, and parking availability at homeside meeting places.

Target Population

With the aim of informing the practice of casual carpooling from the perspective of its participants, the research consultants targeted people who participate in such systems as a regular method of commuting, including both drivers and passengers.

The focus groups did not include people who might be instrumental to casual carpooling in general, such as the Casual Carpooling Scan Study participants, transportation or local government/quasi–government entities with interests in ridesharing and carpooling programs, other researchers from universities, or people who are associated with casual carpooling systems such as those who donate time and energy in facilitating the practice through the management of public Web sites and discussion boards. Rather, these individuals were consulted within the planning phases of the focus groups and were invited to observe the focus groups. They provided insights on the systems regarding study locations, options for recruiting focus groups, and locations for holding the focus groups

Study Locations

Focus groups were conducted in three metropolitan areas: Washington, DC; Houston, TX; and San Francisco, CA. Several factors contributed to the evolution of each system in the respective locations; each is briefly presented within the next subsections.

Mapping Tools

Figures 1, 2, and 3, appearing in this section, were created using ArcGIS® software by Esri. The base map is the World Topographic map from Esri; the major road lines are data from the United States Census Bureau; the park–and–ride and casual carpooling locations were manually created in ArcGIS by finding each location on the base map and creating a point; reference addresses are listed on each of the following Web sites and were retrieved in February 2013:  www.slug–lines.com/Slugging/Map.asp (Washington, DC, region), www.ridemetro.org/SchedulesMaps/parkride.aspx (Houston, TX, region), and www.ridenow.org/carpool (San Francisco, CA, region). ArcGIS® and ArcMap™ are the intellectual property of Esri and are used herein under license.

Washington, DC

In the Washington, DC, area, casual carpooling is commonly referred to as “slugging.” As shown in figure 1, casual carpooling occurs in the Washington, DC, area primarily along Interstate (I) 95 and I–395 between Washington and Northern Virginia, extending as far south as the north side of Fredericksburg, VA. A few “slug lines” also operate along I–66 heading westbound out of Washington to Manassas, VA. Casual carpooling in this region is equally active during the morning (starting as early as 5:30 a.m. and lasting until 8:45 a.m.) and afternoon (starting as early as 3 p.m. and continuing until 6 p.m.) commutes.

AMENDED June 3, 2013

A map shows the Washington, DC–Northern Virginia metropolitan region, including an inset for downtown Washington, DC. Major roads and park–and–ride lot locations are marked. West of the Potomac River, in Virginia, locations are close to I 95 or its feeder routes, spanning the distance from Stafford County in the south to Arlington County in the north, where several sites are clustered near I 395 and the river. Inside Washington, DC, most of the pickup sites shown are on 14th Street, a direct route across the Potomac River on I–395. Sources: U.S. Census, www.slug–lines.com, Esri. Prepared by NuStats LLC 2013. Map used by permission. Copyright © Esri. All rights reserved.
Figure 1. Map. Casual carpooling locations in the Washington, DC, region.

 

Several dominant environmental features of the Washington area’s transportation network have contributed to the region’s casual carpooling system:

Information on casual carpooling in the Washington–Northern Virginia region is available at www.slug–lines.com. This Web site contains comprehensive details on the morning and afternoon casual carpooling (or slugging) locations, etiquette and rules for casual carpooling, hints for getting started, a discussion board, and more. Unique to the site is a history of casual carpooling in the region and information on other casual carpooling programs in the United States and beyond.(4)

Houston, TX

As in the Washington, DC, region, some casual carpoolers in Houston also refer to casual carpooling as “slugging.” Casual carpooling occurs along two major corridors leading into Houston: the Katy Freeway (I–10) and the Northwest Freeway (US Highway 290). Along the Northwest Freeway, there is one morning casual carpooling location (Northwest Station Park–and–Ride lot), and along the Katy Freeway, there are two morning casual carpooling locations (Addicks Park–and–Ride and Kingsland Park–and–Ride lots).(5) Figure 2 shows the park–and–ride locations that are listed on the Metropolitan Authority of Harris County Web site (www.ridemetro.org) and the three casual carpooling locations: Northwest Station, Addicks, and Kingsland.(6)

A map shows the Houston, its inner and outer loop routes, and its outer suburbs. The three casual carpooling locations are marked: (1) Addicks and (2) Kingsland lots on the Katy Freeway and (3) the Northwest Station lot on US Highway 290. All three lie west of the city. The park–and–ride sites are widely and fairly evenly distributed on the beltway route and about nine routes running into the city. Sources: U.S. Census,www.ridemetro.org, Esri. Prepared by NuStats LLC 2013. Map used by permission. Copyright © Esri. All rights reserved.
Figure 2. Map. Park–and–ride locations in the Houseton, TX, region.

 

According to the Casual Carpooling Scan Report, casual carpooling activity in Houston has dropped an estimated 50 percent in volume in recent years.(1) This reduction is largely due to changes since 2010 along the Katy Freeway, the Houston region’s major east–west highway, extending approximately 40 mi (65 km) from the central business district west to the Brazos River. The original highway was constructed in the 1960s with three lanes per direction and two frontage lanes, but in 2008 the Texas Department of Transportation completed a reconstruction of a 12–mi (19 km) section of the Katy Freeway from west of State Highway 6 to the I–10 interchange. The reconstruction added lanes in each direction, and the limited access portion was changed from HOV to a variable priced high–occupancy toll (HOT) lane. Now with nine lanes in each direction (three frontage lanes, four general purpose lanes, and two managed HOT lanes), the increased capacity has significantly reduced congestion on the general purpose lanes, making the associated time savings less significant. Additionally, drivers now have the option to drive alone and pay a toll on the HOT lanes. They are no longer required to have a passenger to benefit from the HOT lanes.

San Francisco, CA

Casual carpooling began in the East Bay area of San Francisco in the 1970s in response to congestion associated with crossing the San Francisco–Oakland Bay Bridge. While carpoolers using HOV lanes were spared having to pay the toll upon westbound crossings of the bridge, they also benefited by significant time savings over the general purpose lanes during peak commuting hours. In July 2010, carpool drivers began paying a reduced toll of $2.50 (full fare is $6 for passenger vehicles during commuting hours) to use the designated HOV lanes during specified times (between 5 and 10 a.m. and between 3 and 7 p.m.). Carpools must have three passengers to get the discounted toll. Because the toll is only charged in the westbound direction, there is significant morning congestion at the westbound bridge approach, and travel is oriented towards San Francisco for work, casual carpooling primarily occurs in the morning and passengers rely on transit for their evening, eastbound commutes. At the time of this report, the Bay Area had not yet implemented managed/priced lanes in the casual carpool corridor. Eventually, when managed/priced lanes are implemented in this corridor, carpoolers are expected to continue to be allowed to use these lanes at a free or reduced fare, providing for yet another incentive to carpool.

Based on the locations listed on www.ridenow.org/carpool, a Web site for casual carpoolers in the San Francisco region, casual carpooling in the region occurs as far north as Vallejo and neighboring cities in American Canyon, as shown in figure 3.(7)

People who initiate their commute from Vallejo and neighboring cities experience additional challenges not faced by casual carpoolers who travel from cities closer to San Francisco, such as Berkeley and Oakland. Such challenges include:

Research Protocols

To fully investigate the experiences, thoughts, and opinions of the target population on topics related to casual carpooling, the research design used focus groups. The consulting firm for this study held two to three focus groups in each of the three metropolitan areas of the study. Focus group participants included drivers and passengers who were current participants in casual carpooling or, in the case of Fort Belvoir, VA, which had no casual carpoolers, participants included drivers and passengers who had past experience or interest in casual carpooling.

A map shows the coast of northern California, with San Pablo Bay and San Francisco on the west, the Bay Bridge, Oakland, Berkeley on the east, and I–880 and I–80 running north to cross the Carquinez Strait to Vallejo and northeast to Fairfield. Carpooling locations are shown clustered in the Oakland/Berkeley area, with several along I–980 and I–80, as well as one each in Vallejo and Fairfield, and several near State Route 24 between Berkeley and Walnut Creek. Sources: U.S. Census,www.ridenow.org/carpool, Esri. Prepared by NuStats LLC 2013. Map used by permission. Copyright © Esri. All rights reserved.
Figure 3. Map. Casual carpooling locations in the San Francisco, CA, region.

 

A challenge in recruiting focus group participants was that because of the very organic and largely unstructured nature of casual carpooling systems, there are no readily available rosters or lists of participants. Therefore, recruitment of study respondents was conducted in consultation with local experts who assisted with recruitment, advised on recruitment approaches, and in some cases collaborated by assisting with recruitment through workplace emails.

A further complication in the research design was in deciding when and where to hold the focus groups. Focus group facilities are generally located in metropolitan area city centers and commercial/business districts and offer many benefits including handling of logistics and hosting, audio– and videotaping of sessions, providing refreshments and distributing incentives, and separate viewing for observers using a one–way mirror. Experience dictates that focus groups with those who work during the day are best held in the evening. The facilitator opted to hold the focus groups in locations that were close to the dropoff locations (or in the case of San Francisco, near transit or home destinations). Because there were no focus group facilities in these locations, the sessions were held in hotel meeting rooms, with observers viewing in an adjacent room via video connections to a television.

A summary of the research protocols follows:

For each session, light refreshments were provided. All focus group participants were offered a cash token in appreciation for their time. This research was conducted under the Information Collection Request OMB Control No. 2125–0629, ICR Reference No: 201111–2125–002.

Participant Summary

A total of 83 respondents participated in eight focus groups. Tables 1, 2, and 3 document the participation for the focus groups by location. No demographic goals were specified for this study, only a target number of respondents to gain sufficient participation; i.e., at least 12 respondents in each focus group. In the event that more than 12 participants arrived for the focus group, it was left to the moderator’s discretion to determine how many respondents would be invited to join the focus group. Qualitative research groups are limited in the number of participants to enrich the conversation. Groups of six to eight participants each are ideal and allow time to probe topics and reach a deeper level of understanding than is possible with a larger group. In focus group research, over–recruitment of participants is a standard practice to account for those who do not or cannot meet their commitment. Where demographic or carpooling behavior information is missing in the tables, this is generally either because the participant declined to provide the information or because the information was not collected during the intercept recruitment, when time available to talk to prospective participants–passengers standing in lines for a ride or drivers waiting for passengers to arrive–was often insufficient. The demographic information was self–reported by the participants and was not observed, collected, or validated through other methods.

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

Region Demographic Information Casual Carpooling (CC) Behavior
Gender Age Education Race Role CC to and from Work? Frequency
Fort Belvoir, VA
May 22, 2012

11:30 a.m.–1 p.m.
Female No response No response Black /
African American
Neither Neither Never
Female No response No response Black /
African American
Driver & passenger Both On occasion
Female No response No response Black /
African American
Neither Neither No response
Female No response No response Black /
African American
Neither Neither Never
Female No response No response White / Caucasian Driver & passenger Both No response
Female No response No response White / Caucasian Driver & passenger Both No response
Male No response No response White / Caucasian Former driver & passenger Both Daily
Male No response No response White / Caucasian Former driver & passenger Both Daily
Female No response No response Black /
African American
Neither No response No response
Male No response No response White / Caucasian Driver & passenger No response No response
Female No response No response Black / African American Former passenger Both On occasion
Female No response No response Black / African American No response No response No response
 
Washington, DC
May 23, 2012

5:30–7 p.m.
Female 52 Bachelor’s or undergraduate degree Black / African American Driver & passenger Both About twice a week
Male 42 Bachelor’s or undergraduate degree Black / African American Driver & passenger Both Daily
Female 35 Bachelor’s or undergraduate degree White / Caucasian Driver Both Daily
Female 58 Graduate / professional degree White / Caucasian Driver Both About twice a week
Male 44 Bachelor’s or undergraduate degree White / Caucasian Driver Both No response
Female 35 Graduate / professional degree Black / African American Driver & passenger Both Daily
Female 40 Some college credit White / Caucasian Driver & passenger Both Daily
Male 43 Bachelor’s or undergraduate degree White / Caucasian Driver & passenger Both Daily
Female 33 Graduate / professional degree Hawaiian / Spanish Driver Both Daily
Male 44 Graduate / professional degree White / Caucasian Driver Both About twice a month
Female No response No response No response Driver Both No response
Male 46 Bachelor’s or undergraduate degree White / Caucasian Passenger Both About twice a week
Male 38 Bachelor’s or undergraduate degree White / Caucasian Driver & passenger Both Daily
Male 39 Bachelor’s or undergraduate degree White / Caucasian Driver & passenger Both About twice a week
Female 56 No response Black / African American Passenger Both Daily
Male 50 Graduate / professional degree White / Caucasian Passenger Both About twice a week
Female 25 Graduate / professional degree White / Caucasian Passenger Both Daily
Male 46 Graduate / professional degree White / Caucasian Driver & passenger Both Daily
Female 43 Graduate / professional degree Black / African American Driver & passenger Both Daily
Female 39 Some college Black / African American Driver & passenger Both Daily
Male 47 Some college Black / African American Driver & passenger Both Daily
Male No response No response No response Driver & passenger Both Daily

 

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

Region Demographic Information Casual Carpooling (CC) Behavior
Gender Age Education Race Role CC to and from Work? Frequency
Houston, TX
July 11, 2012
5:30–7 p.m.
Female 51 Some college credit White / Caucasian Driver Both About twice a week
Male No response No response No response Driver No response No response
Female 54 High school graduate White / Caucasian Passenger No response No response
Female 61 Bachelor’s or undergraduate degree Hispanic / Latino Passenger To work Daily
Male 63 Bachelor’s or undergraduate degree White / Caucasian Passenger To work About twice a week
Male No response No response No response Driver & passenger Both Daily
 
Houston, TX
July 11, 2012
7:30–9 p.m.
Male No response No response No response Primarily a passenger No response No response
Female No response No response White / Caucasian Primarily a passenger No response No response
Female No response No response White / Caucasian Primarily a passenger No response No response
Male No response No response White / Caucasian Driver & passenger No response No response
Male No response No response No response Driver & passenger No response No response
Male No response No response Asian / Pacific Islander Primarily a passenger No response No response
Male 56 No response White / Caucasian Primarily a passenger Both No response
Female No response No response Hispanic / Latino Driver & passenger No response Daily
Female No response No response White / Caucasian Driver & passenger No response No response
Female No response No response White / Caucasian Driver & passenger No response No response

 

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

Region Demographic Information Casual Carpooling (CC) Behavior
Gender Age Education Race Role CC to and from Work? Frequency
Oakland, CA
August 22, 2012
5:30–7 p.m.
Male 31 No response No response Driver To work Daily
Male 49 No response Black / African American Driver To work Daily
Male 30 Graduate / pro­fessional degree Asian / Pacific Islander Driver & passenger To work Daily
Female No response Bachelor’s or undergraduate degree Hispanic / Latino Passenger To work Daily
Female 44 Bachelor’s or undergraduate degree No response Passenger To work No response
Male No response No response No response Primarily a passenger No response No response
Female 32 Bachelor’s or undergraduate degree Black / African American Passenger No response About twice a month
Male No response No response No response Passenger To work Daily
Male 32 Bachelor’s or undergraduate degree Asian / Pacific Islander Primarily a passenger To work About twice a week
Male No response No response No response No response To work Daily
Female 36 Bachelor’s or undergraduate degree Black / African American Passenger To work Daily
Male 35 Bachelor’s or undergraduate degree Hispanic / Latino No response To work Daily
Female No response No response No response Passenger To work Daily
 
Oakland, CA
August 22, 2012
7:30–9 p.m.
Female No response No response No response Primarily a driver No response No response
Male No response No response No response Driver & passenger To work Daily
Male No response No response No response Driver & passenger To work No response
Female No response No response No response Primarily a passenger To work Daily
Male No response No response No response Passenger To work About twice a week
Female No response No response No response No response No response No response
Male 50 Bachelor’s or undergraduate degree White / Caucasian Primarily a passenger No response No response
Female No response No response No response Passenger No response No response
Female No response No response Asian / Pacific Islander Primarily a passenger No response No response
Female 46 Bachelor’s or undergraduate degree Black / African American Primarily a driver To work No response
Male 56 Graduate / pro­fessional degree White / Caucasian Primarily a passenger To work No response
Male 33 No response No response Primarily a driver To work No response
 
Vallejo, CA
August 23, 2012
7–8:30 p.m.
Male No response Bachelor’s or undergraduate degree Asian / Pacific Islander Primarily a passenger Both Daily
Female 49 Some college Asian / Pacific Islander Primarily a passenger Both Daily
Female 27 Bachelor’s or undergraduate degree Hispanic / Latino Primarily a driver No response Daily
Female No response No response No response Primarily a passenger No response No response
Male No response No response Hispanic / Latino Primarily a passenger No response No response
Male No response No response No response No response To work Daily
Female No response No response Hispanic / Latino Primarily a passenger No response No response
Male No response No response No response Primarily a passenger No response About twice a month

AMENDED June 3, 2013

 

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