Acronyms
SSD
What is stopping sight distance?
Horizontal distance measurement units
What are stations?
The primary color of a yield road sign
What is red?
Number of vehicles divided by the length of road
What is Density?
Process for determining if a traffic signal is necessary at an intersection?
What are traffic signal warrants?
PVI
What is point of vertical intersection?
The horizontal distance between a vertical curve PVC and PVT.
What is the length of the curve?
Number of feet in a mile.
What is 5280?
The two types of traffic speed
What is time mean speed & space mean speed?
The technical name for the yellow light duration
What is the change interval.
LOS
What is Level of Service?
The point with zero slope along a vertical curve
What is the high/low point?
The time it takes for a driver to detect and obstruction in the road and begin to press the brake to stop (generally assumed to be 2.5 seconds)
What is perception-reaction time?
The base free flow speed for a Multilane highway with a 55mph speed limit
What is 60mph?
The alternate name for the all-red time during a traffic signal phase?
What is all-red time?
AADT
What is Annual Average Daily Traffic?
Metric that defines the characteristics of horizontal and vertical curves
What is the design speed?
The name of the town where Dr. Barlow lives.
What is Show Low?
The theoretical speed of traffic when density is zero
What is free-flow speed?
The total time for a traffic signal to complete all of the phases
What is cycle length?
TSI
What is Terminal Serviceability Index?
The angle subtended by a 100-ft arc along a horizontal curve.
What is the degree of curvature?
The name of the group that sets most geometric design standards for roadways in the United States.
What is AASHTO?
The time between the passage of the front bumpers of successive vehicles at some designated highway point.
What is headway?
The time deducted from the green time resulting from drivers responding to the light turning green and beginning to accelerate
What is start up lost time?