Estimating Vehicle-miles Traveled In North Carolina

The Vehicle-Miles Traveled (VMT) data is one of the most important measures to evaluate the performance of road systems and extensively used in vehicle emission estimate, air quality analysis, energy consumption calculating, traffic impact assessing etc. Estimation methods of AADT and VMT can be classified into two broad divisions: traffic-count-based and non-traffic-count-based. Typically the traffic-count-based VMT estimation has better accuracy than the latter one; however, it requires a large number of actual data from roads. Because of the limitation of labor and facility, it's impossible to cover all the roads. In order to estimate VMT of uncovered roads, every state is using different methodology by considering the pattern of their road network. However, it is well recognized nationwide that to estimate the accurate VMT of uncovered roads is a tough issue. North Carolina Department of Transportation (NCDOT) is using traffic-count-based VMT estimation method. The purpose of this research is to improve the accuracy of VMT estimation North Carolina by following the requirement of NCDOT. The research results of this thesis are presented as following:First, a survey is done to understand the methodology of VMT estimation using by NCDOT. By comparing with other states'methodology, an assessment is done to evaluate the methodology using by NCDOT.Secondly, by consider that community road is the majority of the uncovered roads in North Carolina, this paper presents 3 kinds of community model in order to estimate the VMT of community based on road topology and household data. Those models can be classified into microscopic traffic model. The first one is community model based on shortest path, the second one is based on least cost by introducing a turn penalty, the last one is community model based on probability and turn penalty.