UC Irvine Institute of Transportation Studies

The literature of transit research contains few studies which have examined the effects of environmental and operational factors on the performance of public transit. The existence and strength of these effects, however, are often the basis for argument against quantitative evaluation of performance. Environmental conditions such as the location and character of the population being served, the geographic nature of the transit service area, prevailing wage rates in an area, and operational characteristics such as organizational structure, vehicle age, and vehicle passenger capacities certainly affect quantitative performance indicators and their interpretation. 

At the same time, little effort has been made toward applying evaluative techniques proven in other fields to the evaluation of transit performance. Procedures do exist--in agriculture, for example--for the aggregation of operational statistics into single indices of technical efficiency. 

Extensive collection of operating and financial data from 47 public transit operators in California for UMTA Research and Training Grant CA-11-0014, "Development of Performance Indicators For Transit," facilitated initial analysis efforts in each of these areas.1 Data was obtained primarily from public documents, with missing, and additional data elements supplied by representatives of each transit property. Even with the high commitment of time and resources made by this project to assembling and verifying this data, its reliability and uniformity were found to be inadequate for statistical analysis. 

The following two sections describe the application of the collected operating and financial data to two multivariate statistical techniques. The first technique, production function analysis, examines the use of a unified efficiency measure on public transit. The second technique, multiple regression analysis, investigates the effects of particular operational characteristics on indicators of transit performance.