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

Transportation’s Role in Reducing U.S. Greenhouse Gas Emissions: Volume 2
which may benefit or impact different people in different ways. The FY 2008 budget for
the Metropolitan Washington Council of Governments’ (MWCOG) regional Commuter
Connections program was approximately $5 million, of which the largest expenses were
$2.2 million for marketing and $1.0 million for employer outreach; other expenses included
ridematching coordination and technical assistance ($0.6 million), a guaranteed ride home
program ($0.5 million), a telework program, information kiosks, and evaluation. Other
major State and regional TDM programs typically employ five to 10 full-time staff
equivalents, in addition to program expenses (Cambridge Systematics for Utah DOT,
unpublished data). A 2002 review of the Federal Congestion Mitigation and Air Quality
Improvement (CMAQ) Program, which is a common source of funding for trip reduction
programs, identified annual costs ranging from $170,000 to $3.5 million per year for eight
regional TDM outreach and promotion programs. Costs ranged from $20 million to $376
million per year for regional employer trip reduction requirements such as California’s
Regulation XV, including private-sector costs (TRB, 2002).
Subsidies or incentives for alternative modes represent a transfer payment rather than a
net social cost, but nonetheless represent a public-sector expense. A regionwide program
of transit subsidies of $30 per month, reaching 10 percent of the workforce, might incur a
public-sector cost on the order of $30 million annually for a metropolitan area with a
population of two million.
Cost-effectiveness estimates for employer TDM programs have varied widely, depending
upon which costs are included and which types of programs are evaluated. Studies that
only include public-sector program costs (and not private costs or transit subsidies) have
produced the most favorable cost-effectiveness estimates. The Moving Cooler study
estimated a direct cost-effectiveness of less than $40 per ton for mandatory trip reduction
requirements coupled with regional support services, or a savings of nearly -$1,000 per
tonne when vehicle operating cost savings are considered. MWCOG, which has
sponsored some of the most rigorous evaluations of its TDM programs, has estimated the
cost-effectiveness of the Commuter Connections program to be $0.01 per VMT reduced or
$32 per ton CO2e (MWCOG, 2009). A calculation based on data in the 2002 CMAQ
evaluation report developed a median cost-effectiveness estimate for worksite-based TDM
projects of $180 per ton, considering only CMAQ program funding (i.e., public sector
costs). However, there is considerable uncertainty in this estimate because it was backcalculated
from cost-effectiveness data on criteria pollutant reductions, and also because
individual project cost-effectiveness ranged from as low as $18 per ton to over $4,300 per
ton (Cambridge Systematics, 2009).
Including private sector costs—such as costs to businesses of hiring a transportation
coordinator, preparing TDM plans, etc., to comply with a TDM requirement, or hardware
and software costs for telecommuting—produces much less favorable cost-effectiveness
estimates. A review of studies of California’s trip reduction requirements estimated a
typical cost-effectiveness of $10.30 per vehicle round-trip avoided, with the vast majority
of costs borne by the employer (Apogee, 1994). At the commute average of 24 miles per
trip, current vehicle efficiencies, and inflating to 2008 dollars, this translates into about
$1,400 per tonne of CO2e reduced ($2,000 with projected 2030 vehicle efficiencies). A
different study that reviewed 22 employer TDM programs nationwide found average costs
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