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

Transportation’s Role in Reducing U.S. Greenhouse Gas Emissions: Volume 2
subscription fees (Winters and Cleland, no date). Some State and regional agencies have
subsidized vanpools to increase viability and ridership. For example, the Denver Regional
Council of Governments’ FY 2009 budget includes about $500,000 for vanpool subsidies,
and the Washington State DOT allocated $8.6 million to vanpool programs in the 2005-
2007 biennium. A review of vanpool programs found a median operating cost of about
$10 per vehicle-mile in 1995 (Winters and Cleland, no date), which translate into a costeffectiveness
of over $20,000 per tonne CO2e reduced; including vehicle operating cost
savings to former drivers would reduce this figure somewhat but not entirely. 40
Cobenefits
Ridesharing and vanpooling can constrain schedules and lengthen commutes, which may
be considered a reduction in mobility. As long as participation is voluntary, however,
travelers will not be made worse off by the program (i.e., the benefit of reduced costs more
than offsets the additional travel time). The typical vanpooler sacrifices 10 to 12 minutes of
travel time compared to driving alone, trading time off against other attributes such as
reduced travel cost and stress (Evans and Pratt, 2005).
Feasibility
One significant barrier to ridesharing and vanpooling is the inconvenience to travelers
associated with identifying appropriate travel partners and undergoing longer commutes.
The popularity of ridesharing and vanpooling over time has been directly related to
energy prices. As gasoline becomes more expensive, travelers are more willing to trade
commuting time for reduced vehicle operation. The need for flexibility in work schedules,
as well as to travel to other activities outside of work, also limits the potential for
ridesharing; many ridesharers only do so a limited number of days per week when they
are traveling from home to work and back.
The market for vanpooling is limited to longer-distance commuters at large employers or
in large employment centers; as of the early 1990s less than 8 percent of the U.S. workforce
both worked for a company with at least 100 employees and lived at least 15 miles from
work (COMSIS and ITE, 1993). Employer vanpools would in most cases be operated by
employers with hundreds or thousands of employees at a single location.
Another barrier involves ensuring that information about programs make it to the level of
the individual traveler. An aggressive, regionally coordinated marketing and outreach
program is generally required in order to ensure that information and programs are
40 The cost-effectiveness calculation assumes 2.8 billion new vanpool vehicle-miles per year
(1.22 million new vanpoolers * 80 percent utilization (4 days/week) * 250 days/year operation/
6 persons/vanpool), or $28 billion in total new vanpool operating costs. Assuming 7.3 billion
annual displaced VMT by auto drivers (1.22 million new vanpoolers * 75 percent former SOV *
(250 * 0.8) days/year * 40 miles/round-trip), the vehicle operating cost savings would be $4.4 billion
at an average cost of $0.55 per mile, for a net cost-effectiveness of $18,800 per tonne.
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