ABSTRACT
Basic parameters for a traf c stream of vehicles traveling along a roadway are
q: traf c ow (vehicles per unit time) k: concentration (vehicles per unit distance of roadway) v: speed (distance per unit time)
Traf c ow, q, is the number of vehicles passing a point per unit time, typically measured in vehicles per hour. Concentration (or density), k, is the number of vehicles per unit length of roadway, typically measured in vehicles per kilometer or vehicles per mile. Speed, v, denotes the instantaneous speed of a given vehicle (also known as spot speed), typically measured in kilometers per hour or miles per hour.
