Vehicles Characteristics:

The physical characteristics of vehicles and the proportions of various vehicles sizes are important control factors in highway design. To obtain such control factors, all vehicles are grouped in general classes and representative types within each class are selected as the “design vehicle”.

Design vehicle: is a selected motor vehicle which is used for the determination of design controls. The most importantvehicle features for highwaydesign are:

1. Weight and axle loading as a controlfor pavement structural design and maximumgrade determination.

2. Dimension and minimum turning radius as a control for highway geometric design which includes lane width, shoulder width, length and width of parking pays…etc.