Road user Characteristics (Traffic Characteristics)
According to S.K.Khanna and S.E.G.Justo from book Highway Engineering, Traffic Engineering is the branch of engineering which deals with the improvement of the traffic performance of road networks and terminals. For achieving that we have to perform systematic traffic studies, analysis and then its engineering application.
|Road users (Google images)|
First of the most important scientific study is the study of the traffic characteristics. Traffic can be classified into two classes:
- Road Users.
- Vehicular traffic.
- Road user characteristics
The various factors which affect road user characteristics may broadly be classified under four heads:
- Physical characteristics: The permanent physical characteristics of the driver are vision, hearing, strength and the general reaction to the traffic situations.
- Vision include the acuity of vision, peripheral vision and eye movement; glare vision, glare recovery and depth judgement. Field of accurate, clear vision is about a 3 degrees cone however the vision is fairly satisfactory up to 10 degrees in general and 20 degrees in horizontal plane.In vertical plane the vision may be limited to 2/3 of that in horizontal plane.
- Hearing is helpful for drivers but of more important for the pedestrians and cyclists.
- Strength is not an important factor in general , lack of strength may make parking maneuvers difficult, particularly for heavy vehicles.
- Mental Characteristics: Knowledge, skill, intelligence, experience and literacy can affect the road user characteristics. Knowledge of vehicle characteristics, traffic behavior, driving practice, rules of roads and psychology of road users will be quite useful for safe traffic operations.
- Psychological factors: These effect reaction to traffic situations of road users to a great extent. Attentiveness, anger, fear, anxiety, phobias, superstition, and impatience may effect the traffic performance to great extent.
- Environment factors: The various environmental conditions affecting the behavior of road user are traffic stream characteristics, facilities to the traffic, atmospheric conditions and locality. The traffic stream may consist of mixed traffic or heavy traffic whereas facilities to overtake to the faster vehicles may be limited. The behavior of the driver varies from one traffic stream to another.