Transit Information Center

Service Mileage Share by Mode 2002 vs. 2007

The clean bus share of vehicle miles increased from 8% in 2002 to 15% in 2007.

The conventional diesel/gas bus share decreased by 10% from 2002 to 2007, but is still the largest share.

Data sources: The Federal Transit Administration’s (FTA) National Transit Database (www.ntdprogram.gov)

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.