Abstract
In many theoritical and empirical researchs, a modified BPR type link performance function which was developed in Holland is used in traffic assignment procedures. As this kind of function appears a relation between average travel time and traffic volume per hour, it is not available to use it directly in assignning an entire day's traffic volume to road network.
In this paper, we theoritically introduce a BPR type link performance function for use in traffic assignment for an entire day and suggest some methods to estimate its functional form on the assumption that travel time of each car running per hour is stochastic variable. Next, we propose a method to practically establish it to each link of real road network. Finally, we verify the applicability of this link performance function by accuracy analysis of network flows and trip time using traffic equilibrium assignment versus servay data.
