Citation

Stock WA, May AD. Transp. Res. Rec. 1976; 615: 20-27.

Copyright

(Copyright © 1976, Transportation Research Board, National Research Council, National Academy of Sciences USA, Publisher SAGE Publishing)

DOI

unavailable

PMID

unavailable

Abstract

A tool developed during the last four years, a microscopic Monte Carlo simulation model of a two-lane, two-way highway, was used to evaluate capacity more accurately. The model operates by processing individual vehicles traveling along a two-lane road where grades and no-passing zones can be specified. The performance of passenger vehicles and trucks is modeled in detail. The validity of the model is demonstrated by comparing specific simulated output to published data obtained under similar conditions. The model is applied in a comparison with the analysis procedures given in the Highway Capacity Manual for two-lane, two-way roads. Satisfactory agreement is obtained between the manual operating speed-volume to capacity ratio curve and a similar relation obtained from model runs. Poorer agreement is obtained between the manual truck equivalency factors for two-lane, two-way roads and similar factors derived from model runs. The conclusion is that the manual may overestimate the adverse effects of trucks on steeper grades. This paper should be of interest to practicing engineers because it introduces an important new tool for detailed evaluation of traffic operations on two-lane highways, and it provides evidence that revision is needed in two-lane highway analysis procedure in the Highway Capacity Manual.