A Microsimulation Model of Truck Speeds on Grades

Abstract

A microsimulation model of acceleration and speed for five vehicle classes on upgrades and downgrades is presented in this paper. Special emphasis is placed upon the interaction of b-double trucks with other vehicles in the traffic stream. A review of existing literature reveals several common findings in previous research, which are used as the basis of the model. The details of necessary calculations involved in the modeling process are shown along with the required background constants. A speed profile of b-doubles on upgrades up to ten per cent is shown. Finally a preliminary study of the effect of replacing semi-trailers with b-doubles in the traffic stream is presented. It is concluded that changing the ratio of b-doubles to semi-trailers under isolated gradient effects does not significantly alter the mean travel times of the entire traffic stream.