Description, Validation and Use of a Model to Estimate Speed Profile of Heavy Vehicles in Grades

This paper describes a model for calculating speed profile for a heavy vehicle uphill in a grade. Weight/power ratio and gradient are the most important input parameters. Calibration and validation of the model is reported. Several heavy vehicles are equipped with a GPS logger, and logged speed profiles from a large number of actual trips are compared with corresponding calculated speed profiles. The results indicate a good accordance between calculated and measured speed. The paper includes a description of the use of the model to calculate delay in grades for different categories of vehicles, as well as some considerations about passing lanes and other use of the model.