Transit Information Center
Percent Share of Clean and Conventional Diesel / Gas Vehicle Mileage 2002 - 2007
The clean vehicle mileage share increased significantly from 28% in 2002 to 35% in 2007, or 368 million miles.
Rapid rail and clean bus accounted for most of this increase.
Conventional diesel / gas bus decreased by 212.8 million miles but the expansion of demand response and vanpool services added 124 and 57.4 million respectively.
Data sources: The Federal Transit Administration’s (FTA) National Transit Database (www.ntdprogram.gov)
Rapid rail and clean bus generated 36.4 and 298 million miles respectively during the period.
Altogether, all clean modes combined generated 368 million miles during the period.
General notes concerning the methodology used to derive service mileage of alternative fuel vehicles:
- The breakdown of service miles by fuel type (clean or conventional diesel/gas) is made through the reported mileage during period for each fleet group in the revenue vehicle inventory form used by the NTD. This mileage is used to derive a proration factor by fuel type which is used to prorate the service mileage (vehicle or passenger car miles).
- Unlinked trips by fuel type are estimated assuming that the service effectiveness (trips per mile) of conventional diesel/gas and clean service is the same. This may not always be accurate at the agency level, but is reasonable at national aggregate level.
- Because the data available does not allow the determination of proration factors because passenger cars (which do not require fuel) cannot be tied to diesel/electric locomotives when both types are used in the provision of service commuter rail was not included in this analysis.