Transit Vehicle Reliability

Transit Vehicle Reliability

Transit service1 interruptions due to mechanical failures remained relatively level from 1995 through 2000,2 averaging between 18 and 19 mechanical problems per 100,000 revenue vehicle-miles [1, 2] (figure 57).

Among transit vehicles, buses and light rail had the highest rates of mechanical failure in 2000. Buses broke down an average of 28 times per 100,000 revenue vehicle-miles, while light-rail vehicles broke down 15 times per 100,000 revenue vehicle-miles. Light-rail vehicle breakdowns have changed the most since 1995. In that year, there were 32 mechanical failures per 100,000 revenue vehicle-miles. However, between 1995 and 2000, the number of light-rail authorities rose to 25, up from 22 in 1995 [1, 2].


1. U.S. Department of Transportation, Federal Transit Administration, National Summaries and Trends (Washington, DC: Annual issues), also available at, as of April 2003.

2. U.S. Department of Transportation, Bureau of Transportation Statistics, National Transportation Statistics 2002 (Washington, DC: 2002), table 1-32 and Transit Profile, also available at, as of April 2003.

1 Here transit service includes:
Light rail—streetcar-type vehicles operated on city streets, semi-exclusive rights-of-way, or exclusive rights-of-way. Service may be provided by step-entry vehicles or by level boarding.
Commuter rail—urban passenger train service for short-distance travel between a central city and adjacent suburb.
Heavy rail—electric railways with the capacity to transport a heavy volume of passenger traffic and characterized by exclusive rights-of-way, multicar trains, high speed, rapid acceleration, sophisticated signaling, and high-platform loading. Also known as “subway,” “elevated (railway),” or “metropolitan railway (metro).”
Demand responsive—nonfixed-route, nonfixed-schedule vehicles that operate in response to calls from passengers or their agents to the transit operator or dispatcher.

2 Data prior to 1995 and later than 2000 were collected using different definitions of what constitutes an interruption of service and are not comparable.