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

Transportation’s Role in Reducing U.S. Greenhouse Gas Emissions: Volume 2
consequent fuel savings could be achieved on all switchyard locomotives, GHG emissions
could potentially be reduced by up to 680,000 metric tonnes CO2e annually. 33
A study examining rail gateway chokepoint improvements in New Orleans estimated that
the improvements would eliminate 91 hours per week of rail idling (Brown Cunningham
Gannuch, 2007). This translates into a reduction of 215 metric tonnes of CO2e per year.
No data have been developed to extrapolate similar estimates to chokepoint
improvements at a national level.
Rail-highway grade separation projects also should have a GHG benefit by reducing
vehicle delay. A study in Riverside County, California estimate that 20 proposed grade
separation projects in the county would eliminate 2,700 daily vehicle hours of delay in
2030, reducing annual GHG emissions by 544 tonnes (Riverside County Transportation
Commission, 2008). Assuming that similar benefits per crossing could be achieved
elsewhere, closing 10 percent of the 225,000 grade crossings in the U.S. would reduce
GHG emissions by 611,000 tonnes annually. 34
Efficiency improvements to rail operations such as switch yard idle reduction can be
implemented relatively quickly—within a few years—compared to major capital
investments such as chokepoint relief. Idle reduction technologies can be applied to
existing locomotives.
The evolution of rail vehicle technology has the potential to affect the future benefits of
operational strategies. In particular, the use of hybrid-electric locomotives would likely
reduce the GHG emissions associated with idling and other inefficient movements,
thereby also reducing the emissions benefits of strategies to reduce these movements.
(Hybrid-electric locomotives are discussed in more detail in Section 3.0, Energy
Efficiency.) However, locomotives tend to have a useful life of 40 years or more, so this
effect will occur slowly as the fleet turns over.
Cost-Effectiveness
Comprehensive cost-effectiveness estimates for the operations benefits of rail
improvements have not been developed. Idle reduction technologies for locomotives can
cost as little as $4,000 to $7,000 for electrification or automatic engine shut-down/start-up,
or up to $35,000 for a diesel-driven heating system; these costs can be offset through fuel
savings. In a test in a Chicago rail yard, the combined savings from locomotive idle
reduction technology was estimated to have a payback period of about 2.5 years at $1.00
per gallon of diesel fuel (EPA, 2004).
33 This calculation assumes total annual switchyard fuel consumption of 311 million gallons (DOT
R-1 forms 2009), 27 percent consumed in idling (Argonne), an 80 percent reduction in idling, and
0.0101 metric tonnes CO2 per gallon of diesel fuel. It does not account for the offsetting fuel use
from the idle reduction technologies.
34 Grade crossing data from FRA (2009).
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