Network Assignment Calibration of BPR Function: A Case Study of Metro Manila, the Philippines

Abstract

The widely used BPR (Bureau of Public Roads) function or volume-delay function (VDF) have some inherent drawbacks where the function should satisfy the representation of the model to the reality. This paper discusses how the calibrated parameters in the BPR function bring improved results of the network assignment by taking an example on the network assignment model in a central business district (CBD) area called Bonifacio Global City (BGC) in Manila, the Philippines. The study area is a newly developed business area where both vehicular traffic and transit are to be well considered in the BGC model. Final recommendation suggested by the paper is to decrease the values of the existing parameters following the Federal Highway Association guideline that sets smaller parameters values. It is proved that the difference of delay between the assignment result and the observation is significantly reduced as the process of calibration is executed.