Desired speed:

A driver's desired speed is randomly assigned when a vehicle enters the network and updated whenever the driver views a different speed limit sign or moves into a segment with a different design speed. The desired speed is calculated as follows:

where:

desired speed of driver n;

speed limit of the segment (or the value the driver viewed on a VSLS);

driver behavior parameters randomly assigned based on the desired speed distribution; and

maximum speed the vehicle can achieve in the segment [FHWA(1980)], a function of vehicle class and grade of the segment (see Table C.5).