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

Transportation’s Role in Reducing U.S. Greenhouse Gas Emissions: Volume 2
Table 5.5 Average Annual Capital Requirement, 2006-2026
Billions of Dollars
Needs Component
5-40
Replacement/
Rehabilitation of
Existing Assets
Maintain Physical Conditions, Improve Service Performance
Total Including Expansion and Modernization of Assets
to Accommodate Annual Ridership Growth at:
2.4% 3.5% 4.6%
Urbanized Area Total $13.9 $40.8 $53.9 $69.9
Rural/Small Urban $0.8 $1.5 $1.5 $1.5
Total Needs $14.7 $42.4 $55.4 $71.4
Source: AASHTO, 2009.
The Moving Cooler study used these estimates of capital investment needs, in conjunction
with estimates of future annual operating costs, to estimate total cost-effectiveness in terms
of GHG reduced for transit system expansion. 21 Considering direct implementation
(capital and operating) costs only, cost-effectiveness to meet the three ridership growth
rates is estimated to be about $1,800 to $2,000 per tonne for urban transit expansion and
$1,200 to $3,000 per tonne for level of service increases. Including vehicle operating cost
savings to private vehicle owners as a result of a reduction in VMT, cost-effectiveness
ranges from $800 to $1,000 per tonne for system expansion and -$260 to +$130 per tonne
for service improvements. Direct cost-effectiveness is not estimated for transit fare
reductions, as the change in fare is simply a revenue transfer from the public sector to the
transit rider; vehicle operating cost savings would provide a net savings of about -$900 per
tonne (Cambridge Systematics, 2009).
Cobenefits
A significant co-benefit associated with transit is its ability to reduce the relative degree
that those who choose not to drive, or who do not own vehicles, are disadvantaged
compared with drivers (VTPI, 2008d). Transit increases accessibility to economic and
social opportunities, and helps achieve equity objectives, such as helping physically and
economically disadvantaged people access public services, education, and employment.
Transit will result in reductions of some criteria pollutant emissions, but may cause
increases in others. The relative emissions impacts will depend upon the vehicle type
(small bus, 40-foot bus, light rail, locomotive, etc.); fuel source (diesel, natural gas, electric);
electricity generation source (for electric rail or trolley bus systems); vehicle emissions
control technology; and operating characteristics of the vehicle (e.g., average speed, time
21 Excluding paratransit services, the estimate for operating costs per unlinked transit trip in 2007 is
$2.61 (FTA, 2008). The cost per unlinked trip is assumed to increase with inflation through 2050.