1 ENERGY AND ENVIRONMENTAL IMPACTS OF ROADWAY GRADES

Although roadway grades are known to affect vehicle fuel consumption and emission rates, there do not appear to be any systematic evaluations of these impacts in the literature. Consequently, this paper addresses this void by offering a systematic analysis of the impact of roadway grades on vehicle fuel consumption and emission rates using the INTEGRATION microscopic traffic simulation software. The energy and emission impacts are quantified for various cruising speeds, under stop and go conditions, and for various traffic signal control scenarios. The study demonstrates that the impact of roadway grade is significant with increases in vehicle fuel consumption and emission rates in excess of 9 % for a 1 % increase in roadway grade. Consequently, a reduction in roadway grades in the range of 1 % can offer savings that are equivalent to various forms of advanced traffic management systems