Perceptionreaction time 15 pts Describe the difference betwe

Perception-reaction time (15 pts) Describe the difference between perception-reaction time for safe stopping distance calculations and those used for determining the length of a signal timing change/clearance interval. 3.

Solution

Difference:-

Perception reaction time for stopping sight distance:-

Stopping Sight distance is a types of sight distance used in road design. It is a near worst-case distance a vehicle driver needs to be able to see in order have room to stop before colliding with something in the roadway, such as a pedestrian in a crosswalk, a stopped vehicle. Insufficient sight distance can adversely affect the safety or operations of a roadway or intersection.

Reaction time for determining the length of signal timing change:-

It indicates the time during which the intersection is not effectively utilized for any movement. When the signal for an approach turns from red to green, the driver of the vehicle which is in the front of the queue, will take some time to perceive the signal (usually called as reaction time) and some time will be lost before vehicle actually moves and gains speed.