chapter  5
32 Pages

Design Controls

The design process must therefore consider three variables – the driver, the vehicle and the road – as well as the interaction between them and the limitations of each. The main feature of all these characteristics is that the designer has no control over them. They are thus inputs to the model, the output of which is the design of all the elements of the road, from the horizontal and vertical alignment to the cross-section and the intersections which are the nodes in the links that form the road network.