The Association of American State Highway and Transportation Officials (AASHTO) assumes that the height of a driver's eye and the height of an object above pavement are which of the following (in inches) when developing recommendations for minimum stopping sight distances?
A)60, 24
B)42, 24
C)42, 42
D)24, 42

Question

Quizplus · Accepted Answer

AASHTO assumes that the height of a driver's eye and the height of an object above pavement are 42 inches and 24 inches (respectively) when developing recommendations for minimum stopping sight distances. AASHTO's recommended distances are a conservative estimate of how long it will take a driver to perceive a situation exists that will require them to stop, apply the brakes, and come to a complete stop. The stopping site distance is an important safety consideration to assure that drivers have a continuous length of visible roadway.