Abstract
The properties of traffic like capacity, intensity, peak hour, efficiency are given. The properties of vehicles like design, braking, acceleration, vision, glare etc. are discussed. The properties of the road like surface, alignment-longitudinal profile, junction etc. are presented. Properties of the driver like psychological aspects, intelligence, vision, attention, hearing, emotion, reaction time, disease, use of alcohol and drugs are given. Properties of traffic accidents and their prevention like safety fences, hard or soft shoulders and registration are presented.