Trust is a program to analyze and evaluate a given set of bus transit routes and associated frequencies, in terms of several descriptors, including measures of user costs, service quality, and operator resources. The procedure assigns a known demand matrix to the transit network according to a path choice logic that explicitly considers transfers. As such, it calculates the percentages of the total demand trips that are able to reach their destination with no transfer, via one transfer, via two tansfers, or simply cannot be satisfied(with two or fewer transfers). Also computed are several node-leveland route-level descriptors for use in the route network planning and design process. After the assignment is executed, the program determines the service frequency necessary on each route to maintain the passenger load factor below a specified maximum. The procedure canbe used iteratively until the calculated frequencies are consistentwith the input frequencies. Trust is written in the lisp language because the latter's "list" data structure representation is particularly well suited to support the path search and enumeration activities inherent in the assignment logic and path choice rules appropriate in a transit network. The application of the program to the transit network of the austin, texas, urban area (with some simplifying assumptions) is presented, illustrating the program's capabilities andcomputational performance. This paper appears in transportation research record no. 1283, Transportation systems planning and applications 1990.
Abstract