Transportation's Role in Reducing U.S. Greenhouse Gas Emissions ...

Ridematching, Carpool, Vanpool
Definition
Ridematching, carpooling, and
vanpooling—which may collectively be
termed “ridesharing”—are typically
commuter-oriented strategies that seek
to reduce VMT by increasing vehicle
occupancies for work trips. Carpooling
involves formal or informal
arrangements between two or more
people to share a ride in a private
vehicle. Vanpools generally consist of 5
to 15 people, including a volunteer
driver-member, that elect to commute
together in a van. Ridematching
involves assisting travelers with finding
suitable partners for carpooling or
vanpooling through on-line databases or
other mechanisms. New technologies
utilizing the Internet and mobile phones
Transportation’s Role in Reducing U.S. Greenhouse Gas Emissions: Volume 2
Ridematching, Carpool, Vanpool
Benefits: Low: 1-5 mmt CO2e in 2030
Direct Costs: Moderate: $80 per tonne (areawide
rideshare matching)
• Higher for vanpools
Net Included Costs: Not estimated
Confidence in Estimates: Low-Moderate
Key Cobenefits and Impacts: Positive
• Mobility benefits through expanded commute
options for workers
Feasibility: High
• Primary ridesharing barrier is providing
adequate incentives (financial or otherwise)
for commuters to participate
• Vanpooling market is limited
Key Policy Options:
• Funding for program support
are facilitating the expansion of ridesharing to nonwork trips, by allowing people to find
suitable ride-sharing partners for trips that do not follow regular patterns. The concept of
forming carpools on very short notice is known as “dynamic ridesharing.” Guaranteed
ride home (GRH) programs, which reimburse employees for the cost of a taxi ride or rental
car if they need to stay late or leave early in an emergency, are an important strategy to
support ridesharing.
Carpooling represents the second most common commuting mode in the U.S., with a
mode share of 12.2 percent according to the 2000 Census. However, the majority of
carpooling is informal—over 60 percent is in two-person carpools with family members
(Pisarski, 2006). Vanpooling has a much lower mode share, at 0.3 percent, and is primary
done only in niche markets serving relatively long-distance commuters to large employers
(the average vanpool trip length according to the 2001 National Household Travel Survey
was 20.4 miles, compared to 12.2 miles for all work trips). Carpooling and vanpooling
both reached a peak in the late 1970s with the oil crisis, then declined after 1980 as gasoline
once again became cheap and less emphasis was placed on ridesharing programs (Evans
and Pratt, 2005). The 2000 carpool commute mode share represents a decline from
13.6 percent in 1990 and 19.8 percent in 1980.
Formal carpool and vanpool programs with the objective of increasing carpooling and
vanpooling were implemented in the 1970s and widely studied in the 1970s and 1980s.
Public sector support for these programs has varied, with more aggressive programs
typically implemented in larger metropolitan areas with significant congestion problems.
Regional vanpooling and ridematching programs are sometimes operated by MPOs, State
DOTs, or transit agencies. Local programs may be operated by municipalities,
5-87