1 ASSESSMENT OF TRAFFIC FLOW BENEFITS OF FLYOVERS:

This paper describes the results of a pilot study of the benefits of a flyover bridge which was constructed over an existing at-grade intersection to increase capacity of traffic flow in two directions on one of the main highway. Under the flyover, the existing traffic signalization for the intersection still uses the same fixed time control plans. This is a main reason why traffic flows underneath the flyover still experience long delays and queue length similar to the situation ‘before’. The purpose of this research is to evaluate the benefits of the flyover. The paper presents the performance of the flyover upgraded intersection and points out the remaining problems including long delays under the flyover. It was found that about 35-40 % of the total traffic volume diverted to the flyover, and despite an increase in traffic volume of +29.46%, at the intersection, the vehicle delays were reduced by 30.41 % over the same period; the saving in travel time and vehicle operating costs amounted t