Comparative analysis of urban transit modes using service-specification envelopes. Paper presented at the 52nd Annual Meeting of the Highway Research Board, Washington, D.C., January 1973.

The development of supply functions for 7 urban transit technologies is described. A supply function is a schedule of service quality that an operator is willing and able to supply for a corresponding schedule of passenger volumes. Comparisons of supply functions among the various modes are made to provide a means of assessing relative qualities of service.