Table of Contents
What is the use of PIEV theory?
1)Perception time: is time required for the sensations received by the eyes or ears of the driver to be transmitted to the brain through the nervous system & spinal cord or it is the time required to perceive an object or situation.
What is PIEV time why it is needed?
The ‘perception time’ is the time required by the driver to realize that the brakes are to be applied. It is the time from the instant the object comes on the line of sight of the driver to the instant he realizes that the vehicle needs to be stopped.
What is total reaction time?
Reaction time of a driver is the time taken from the instant the object is visible to the driver to the instant when the brakes are applied. We know, Total reaction time = Perception time + Brake reaction time.
What does PIEV mean?
Perception, Identification, Emotion, and Volition
Explanation: PIEV means Perception, Identification, Emotion, and Volition.
What is lag distance in transportation?
➢ Lag distance is the distance the vehicle traveled during the reaction time t and is given by vt, where v is the velocity in m / sec. ➢ Braking distance is the distance traveled by the vehicle during braking operation.
What is reaction time in transportation?
Reaction time of a driver is the time taken from the instant the object is visible to the driver to the instant when the brakes are applied. Many of the studies shows that drivers require about 1.5 to 2 secs under normal conditions.
What are the factors affecting reaction time?
There are a number offactors that affect reaction time in humans. These mainly include gender, age, physical and mental fitness, sleep deprivation, consumption of intoxicants, and the sensory regime the stimulus belongs to.
How do you calculate lag distance?
The lag time here is 10 hours….
| Car A | Car B |
|---|---|
| distance = 250 miles speed = 50 miles/hr. Time = Distance / Speed = 250 miles/(50 miles/hour) = 5 hours | distance = 250 miles speed = 25 miles/hr. Time = Distance / Speed 250 miles/(25 miles/hr) = 10 hours |
Which of the following is a static characteristics of vehicle?
Static characteristics of the vehicles affecting the road design are the dimensions, weight and maximum turning angle. Dynamic characteristics of vehicles affecting road design are speed, acceleration and braking characteristics and some aspects of vehicle body design.
What is sight distance explain lagging distance and braking distance?
The lagging distance is the distance that is moved by the vehicle in a time period ‘t’ at a velocity of ‘v’ in m/s. Hence lag distance is ‘vt’. The distance that is traveled by the vehicle during the operation of braking is called as the braking distance.