Science which deals with proper design and layout of rood and ensures easily and safe flow of traffic
Scope of Traffic Engineering
Basic objective is to achieve efficient, free and rapid flow of traffic with least no. of traffic accident.
Following are the main aspects of traffic Engineering
- Traffic Characteristics
- Traffic study and analysis
- Speed(Spot, Speed, delay)
- Origin and Destination (O and D study)
- Traffic flow characteristic
- Traffic Capacity
- Traffic Operation
- Control (Sign, signals and marking)
- Traffic Planning
- Most transit facilities
- Traffic Management through different policies including parking policies.
- Prioritization of public vehicle
- Traffic Administration and Management
- 3 E (Engineering, Enforcement, Education)
- Road user behaviour
- Eyesight, hearing power, smell defect are the physical characteristics which affect the safe driving of vehicles.
- Out of all this vision is the most important.
- Sensing and Vision
- Hearing and Smelling
- Alcohol drink effect
- Drug effect
- Mental Characteristics
- Intelligence, Knowledge, skill, experience comes under mental characteristics of road user
- Knowledge of vehicle characteristics, traffic behaviour, driving practice helps for safe traffic operation.
- Reaction to certain traffic situation becomes more spontaneous with experience.
- Psychological Factor
- Impatient, attentiveness, ability to follow regulations and maturity comes under psychological factor.
- Due to impatience some dangerous accident may take place.
- Due home worries, mind of driver may divert and accident may take place.
- Environmental Factors
- The environmental factors like fog, rain, heat, heavy sun may affect the road uses behaviour.
- Other environmental factors like locality, atmospheric condition also affects and user behaviour.
Characteristics of Vehicle
- Static Characteristics
- Width, length, weight of the vehicle, height of driver seat, clearance below chasis, wheel base are the static characteristics of vehicle.
- Width affects widening lane, width of shoulder, width of parking place.
- Length affects extra widening, road capacity, passing sight distance, parking facility etc.
- Weight affect pavement thickness, requirement of ruling and limiting gradient.
- Height of the driver’s seat affect visibility distance.
- Dynamic Characteristics
- Speed, acceleration and breaking characteristics are the main dynamic characteristics of vehicles.
- Speed of vehicle affect horizontal and vertical alignment design, super elevation, limiting radius etc.
- Vehicle power determines the acceleration produced by vehicle.
- Breaking efficiency determines the rate of retardation of vehicle.
Elements of Driver Decision
PIEV(Perception, Intellection, Emotion and Violation) Concept
Process of perceiving the sensation received through eyes, ears, nervous system and brain.
Process of identifying the stimuli.
Determination of appropriate response to the stimuli.
Physical Response resulting from decision.
Consider a driver approaching the STOP sign
- The driver first sees the stop sign(perception)
- The driver recognize that it is a STOP sign
- He decides to apply brake to stop
- Finally, he puts his foot on brake.
Driver move from one point to another through 3 tasks.
Physical Manipulation of vehicle through lateral and longitudinal control by steering, acceleration, braking
Refers driver’s decision process, a task of selecting safe speed, path on the road.
Refers driver’s ability to execute the trip from origin to destination.