Ridesharing

Carpooling and Vanpooling

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TDM Encyclopedia

Victoria Transport Policy Institute

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Updated 22 July 2008

This chapter describes “Ridesharing,” which refers to carpooling and vanpooling. Rideshare programs include ridematching services (which help travelers find travel partners), and strategies that give rideshare vehicles priority in traffic and parking.

 

 

Description

Ridesharing refers to carpooling and vanpooling (the term is sometimes also applied to public transit, particularly commuter express bus), in which vehicles carry additional passengers. Carpooling uses participants’ own automobiles. Vanpooling usually uses rented vans (often supplied by employers, non-profit organizations or government agencies). Most vanpools are self-supporting – operating costs are divided among members. Vanpooling is particularly suitable for longer commutes (10 miles or more each way).

 

Ridesharing has minimal incremental costs because it makes use of vehicle seats that would otherwise be unoccupied. It tends to have lower costs per vehicle-mile than public transit because it does not require a paid driver and avoids empty backhauls. However, Ridesharing is generally only suitable for trips with predictable schedules such as commuting or attending special events.

 

Table 1            Comparing Travel Modes                                        

 

Driver

Vehicle Ownership

Vehicle Size

User Schedule Flexibility

Conventional Public Transit

Paid

Public

Large

Flexible

Paratransit

Paid

Public

Medium

Some flexibility

Vanpool

Unpaid

Group Rental

Medium

Inflexible

Carpool

Unpaid

Personal

Small

Inflexible

Taxi

Paid

Business

Small

Flexible

Different modes have different attributes. Modes with paid drivers tend to have relatively high operating costs. Vanpooling and carpooling have low cost per passenger-mile, but are only suitable for prescheduled trips, such as commuting.

 

 

Ridesharing is one of the most common and cost effective alternative modes, particularly in areas that are not well served by public transit. Many commuters rideshare part-time, for example, twice a week. Ridematching is a common component of Commute Trip Reduction programs intended to reduce urban traffic problems. Ridesharing is also an important mobility option for non-drivers, particularly in small towns and rural areas, where notices are often posted on bulletin boards and travel needs are shared through informal networks. Transportation Management Associations, transit agencies and community transportation organizations often provide ridematching services.

 

Ridesharing tends to experience economies of scale: as more people use the service the chances of finding a suitable carpool or vanpool increase significantly. As a result, success depends on promotion programs that encourage a significant portion of potential users to register for possible participation. According to market research by York and Fabricatore (2001), a variety of improvements and incentives can increase Ridesharing:

 

  • Increased flexibility, for example,
    • allowing commuters to vanpool two or three days a week, rather than every day
    • allowing unscheduled use as long as a van has extra space, such as allowing a commuter who misses their regular 5:30 vanpool to use a later van.

 

  • Empty seat subsidies (temporarily paying a share of costs if a vanpool has less than six riders).

 

  • Fare subsidies by employers or transit agencies (currently, transit commuting is often subsidized, but similar trips by vanpools are not).

 

  • Targeted, direct Marketing, for example, calling households in a particular suburb with an offer of one month’s free vanpooling to encourage area commuters to try the service.

 

  • Rent cars for carpools the same as vans are rented for vanpool use. This provides an option for groups of two to five who want to rideshare if none have a suitable vehicle, including vanpools that lose members.

 

  • Premium quality service options, such as extra high-quality vans with bucket seats, workstations (fold-down tables with electric power so vanpoolers can work while commuting), and complementary newspapers and drinks for vanpoolers who pay an extra fee.

 

 

  • Vanpools scheduled to transfer to transit service or other vanpools.

 

 

 

Rideshare programs typically provide carpool matching, vanpool sponsorship, marketing programs, and incentives to reduce driving. Rideshare incentives may include HOV Priority (e.g., HOV highway lanes), preferential parking spaces, and awards. Some employers offer Commute Financial Incentives such as a cash payment to employees who carpool, or a voucher that covers vanpool fees, provided as an alternative to a free parking space. Because they have significant economies of scale (the more people who register, the more effective they are at successfully matching riders), it is helpful if one well-publicized ridematching program serves an entire geographic region.

 

Some innovative ridesharing programs have been proposed to encourage motorists to share rides for individual trips, creating a cross between hitchhiking and taxi service. Some involve pre-registering motorists and riders to increase security, and establishing standard reimbursement rates. In a few locations, casual carpooling has developed, in which motorists pick up riders at established stops in order to take advantage of HOV lanes (Beroldo, 1990). Dynamic ridesharing means that an independent organization matches passengers with drivers for individual trips (as opposed to regularly scheduled trips), using telephone and computer technologies (Behnke, 1996; SST, 1997). King County Metro has incorporated special event ridematching into its regional rideshare program (www.rideshareonline.com).

 

 

How It Is Implemented

Rideshare programs can be implemented by an individual employer as part of a Commute Trip Reduction program, by a Transportation Management Association or a Campus Trip Management program, a transit agency, or by a regional transportation agency. Marketing can inform potential ridesharers about the service. Vanpooling requires more organizational structure to address vehicle ownership, expense recovery and liability issues. Taxi Improvements can include regulatory changes that allow shared taxi ridesharing.

 

Larger ridematching programs use computerized partner matching systems that take into account each commuter’s origin, destination, schedule, and special needs. Smaller programs may simply match potential partners by hand, or use ride notice boards.

 

 

Travel Impacts

Experience indicates that ridesharing programs typically attract 5-15% of commute trips if they offer only information and encouragement, and 10-30% if they also offer financial incentives such as parking cash out or vanpool subsidies (York and Fabricatore, 2001).

 

Rideshare programs that include incentives such as HOV Priority and Parking Cash Out often reduce affected commute trips by 10-30% (Winters and Rudge, 1995). If implemented without such incentives travel impacts are usually smaller. Ewing (1993) concludes that ridesharing programs can reduce daily vehicle commute trips to specific worksites by 5-15%, and up to 20% or more if implemented with Parking Pricing. Evans and Pratt (2005) describe several worksites where 5-20% of employees commute by vanpool. The most effective programs tend to have paid parking, subsidies for alternative modes, and other incentives to encourage reduced automobile commuting.

 

Analysis by Wambalaba, Concas and Chavarria (2004) and Concas, Winters and Wambalaba (2005) indicate that the elasticity of vanpool ridership with respect to fees is -2.6% using a 1997 data set and -14.8% using a less statistically robust 1999 data set, that is, a one dollar decrease (increase) in vanpool fares is associated with a 2.6% to 14.8% increase (decrease) in the predicted odds of choosing vanpool with respect to drive alone. The same study found that the elasticity of vanpooling with respect to price to be -0.61 (1997) and 13.4% (1999), meaning that for each 10% increase in vanpool price, there is a 6% to 13% decrease in vanpool choice with respect to auto. Conversely, a 10% decrease in vanpool price will increase the odds of choosing vanpool (with respect to auto) by 6% to 13%. Using a nested logit model, the study found the elasticity of vanpooling with respect to fares to be -1.14.

 

One study estimates the price elasticity of vanpooling at about 1.5, meaning that a 10% reduction in vanpool fares increases ridership by about 15% (York and Fabricatore, 2001). For example, if vanpool fares that are currently $50 per month are reduced to $40 (a 20% reduction), ridership is likely to increase by about 30% (20% x 1.5). Of course, exact impacts will vary depending on the specific market and whether other ridesharing incentives are also provided. Evans and Pratt (2005) report lower elasticities.

 

Because rideshare passengers tend to have relatively long commutes, mileage reductions can be relatively large. For example, if ridesharing reduces 5% of commute trips it may reduce 10% of vehicle miles because the trips that are reduced are twice as long as average. Rideshare programs can typically reduce up to 8.3% of commute VMT, up to 3.6% of total regional VMT, and up to 1.8% of regional vehicle trips (Apogee, 1994; TDM Resource Center, 1996). See Trip Reduction Tables for more information on the travel reductions that are predicted to occur from financial incentives for ridesharing under various circumstances.

 

Critics argue that rideshare programs are ineffective because, for many years, vehicle occupancy rates declined (Orski, 2001), but their analysis only considered overall trends and ignored the much higher vehicle occupancy rates among employees who have comprehensive rideshare programs, particularly if they include both financial incentives and HOV Priority highway lanes.

 

Table 2            Travel Impact Summary

Travel Impact

Rating

Comments

Reduces total traffic.

2

Reduces vehicle travel.

Reduces peak period traffic.

3

Effective at reducing commute auto trips.

Shifts peak to off-peak periods.

0

 

Shifts automobile travel to alternative modes.

3

 

Improves access, reduces the need for travel.

-1

May encourage sprawl.

Increased ridesharing.

3

 

Increased public transit.

0

 

Increased cycling.

0

 

Increased walking.

0

 

Increased Telework.

0

 

Reduced freight traffic.

0

 

Rating from 3 (very beneficial) to –3 (very harmful). A 0 indicates no impact or mixed impacts.

 

 

Benefits And Costs

Ridesharing can reduce peak-period vehicle trips and increase commuters travel choices. It reduces congestion, road and parking facility costs, crash risk and pollution emissions. Ridesharing tends to have the lowest cost per passenger-mile of any motorized mode of transportation, since it makes use of a vehicle seat that would otherwise be empty. Ridesharing provides consumer financial savings (as estimated in the table below), and time savings if there are HOV Priority facilities. Crash risk declines due to fewer vehicles on the road (TDM Safety Benefits). Rideshare programs improve Transportation Options, and are particularly helpful to commuters who cannot drive or lack a reliable automobile.  The SMART Trip Reduction Manual published by Pollution Probe (2001) provides information on calculating the benefits of ridesharing to employers and employees.

 

Table 3            Estimated Monthly Commuting Costs

Round Trip Miles

Drive Alone

3-Rider Car Pool

10-Rider Van Pool

30

$193

$64

$31

40

$257

$86

$37

50

$321

$107

$43

60

$386

$129

$50

70

$450

$150

$56

80

$514

$171

$63

 

 

Vanpooling is one of the most resource efficient and cost effective motorized modes, and so can provide significant net benefits (Evans and Pratt, 2005). Wambalaba, Concas and Chavarria (2004) summarize average operating costs, revenues, subsidies and ridership for various transit agencies, indicating that a typical vanpool van costs $1,000 to $1,250 per month to operate.

 

Rideshare program costs consist primarily of administration expenses. One ridematch system pilot project was estimated to incur $150,000 in setup and marketing expenses, and an average about $3 per user (i.e., per phone call received) in operating costs (Guiliano, Hall and Golob, 1995, U.S. dollars). Costs to participants may include additional travel and time needed to meet rideshare partners, schedule constraints needed to match commuting times, loss of privacy, and restrictions on stops for errands.

 

Ridesharing may encourage urban sprawl by making longer-distance commutes more Affordable. Transit agencies sometimes consider rideshare as competition that reduces transit ridership. For this reason it is important to track the travel alternative that rideshare passengers would otherwise use.

 

Table 4            Benefit Summary

Objective

Rating

Comments

Congestion Reduction

3

Reduces peak-period automobile travel.

Road & Parking Savings

3

Reduces peak-period automobile travel.

Consumer Savings

3

Provides consumer savings.

Transport Choice

3

Increases travel choice.

Road Safety

2

Reduces vehicle mileage, but increases vehicle occupancy, so crashes that do occur may have more casualties.

Environmental Protection

2

Reduces automobile travel.

Efficient Land Use

-1

May encourage longer-distance commutes and urban sprawl.

Community Livability

2

Reduces automobile trips.

Rating from 3 (very beneficial) to –3 (very harmful). A 0 indicates no impact or mixed impacts.

 

 

Equity Impacts

Rideshare matching services are usually open to anyone in a particular geographic area. Ridesharing services are mostly self-supporting or receive a small subsidy, usually for administrative and marketing activities. Most rideshare program subsidies are modest, usually smaller than the social cost of accommodating automobile travel. For example, if a ridematching service is effective at reducing just a few percent of automobile trips, its expenses can be paid through reduced road and parking facility costs. Rideshare programs generally increase vertical equity by improving Transportation Options for non-drivers and making commuting more Affordable.

 

Table 5            Equity Summary

Criteria

Rating

Comments

Treats everybody equally.

3

Rideshare services are generally available to anybody.

Individuals bear the costs they impose.

2

Most rideshare travel is self-supporting. Although ridematching services require subsides, these are usually less than the social costs of automobile travel.

Progressive with respect to income.

3

Improves travel options for lower-income people.

Benefits transportation disadvantaged.

3

Improves travel options for non-drivers.

Improves basic mobility.

2

Improves access to education and employment.

Rating from 3 (very beneficial) to –3 (very harmful). A 0 indicates no impact or mixed impacts.

 

 

Applications

Rideshare programs can be appropriate in most geographic areas, and tend to be particularly effective at serving relatively dispersed, suburban destinations. They can be implemented by businesses, Transportation Management Associations and other business organizations, local and regional governments. Regional programs are best, because they create a larger pool of potential users than ridematching at a worksite or local level.

 

Table 6            Application Summary

Geographic

Rating

Organization

Rating

Large urban region.

3

Federal government.

1

High-density, urban.

2

State/provincial government.

2

Medium-density, urban/suburban.

3

Regional government.

3

Town.

3

Municipal/local government.

3

Low-density, rural.

3

Business Associations/TMA.

3

Commercial center.

3

Individual business.

2

Residential neighborhood.

2

Developer.

1

Resort/recreation area.

3

Neighborhood association.

1

 

 

Campus.

3

Ratings range from 0 (not appropriate) to 3 (very appropriate).

 

 

Category

Improved Transport Options.

 

 

Relationships With Other TDM Strategies

Ridesharing supports and is supported by many other TDM programs, including HOV Priority, Commute Trip Reduction, Parking Management, Commute Financial Incentives, Flextime (which makes it easier for employees to match schedules), Guaranteed Ride Home services, and Pedestrian Improvements at worksites. In some cases ridesharing competes with transit or non-motorized commute modes.

 

 

Stakeholders

Rideshare programs require support by transportation and sometimes transit agencies, by Transportation Management Associations, or by individual employers. It may involve adoptions of special policies by employees and labor organizations to accommodate and support ridesharing and flextime.

 

 

Barriers To Implementation

Rideshare programs require sufficient funding to provide efficient matching services. Effectiveness depends on appropriate incentives: HOV facilities, financial subsidies, parking management, and ma