ATSSA TRAFFIC CONTROL SUPERVISOR RE-
CERTIFICATION QUESTIONS WITH CORRECT
ANSWERS 2025
Formula for Min. taper length - CORRECT ANSWER -L=(WS²)/60 for 40MPH or less,
L=WS for 45MPH or more
speed used in formulas should be - CORRECT ANSWER -
The off peak 85th percentile. Which is the speed at or below which 85% of vehicles travel operating s
peed in free flow conditions
Distance of L for 25 MPH with 12' Lane width - CORRECT ANSWER -125'
Distance of L for 35 MPH with 12' Lane width - CORRECT ANSWER -245'
Distance of L for 45 MPH with 12' Lane width - CORRECT ANSWER -540'
Distance of L for 55 MPH with 12' Lane width - CORRECT ANSWER -660'
Distance of L for 65 MPH 12' Lane width - CORRECT ANSWER -780'
Merging Taper Length - CORRECT ANSWER -L Minimum
Shifting Taper Length - CORRECT ANSWER -1/2 L Minimum
Shoulder Taper Length - CORRECT ANSWER -1/3 L Minimum
One-Lane, Two-Way Taper (Flagger taper) Length and number of devices - CORRECT ANSWER -50'-
100' regardless of speed
6 devices 10'-20' apart
, Downstream taper Length - CORRECT ANSWER -50'-100' per lane
Tangent distance (between tapers) - CORRECT ANSWER -2L
Tangent distance before shifting taper - CORRECT ANSWER -1/2L
Activity Area Sub-components (3) - CORRECT ANSWER -Buffer Space
Work Space
Traffic Space
Longitudinal Buffer Space - CORRECT ANSWER -Recovery Area for errant vehicles: Forgiving design
Protects workers and Motorists
Always completely empty or clear
No vehicles, truck-mounted attenuator, equipment, or materials
STRONGLY RECOMMENDED: unless there is a documented reason not to
Termination Area is:
can contain: (2) - CORRECT ANSWER -Where road users are returned to their normal path
extends from the downstream end of the work area to the last device such as end work zone sign
May contain:
end work zone sign: usually 500' past last device
downstream taper = 50'-100' per lane
Recommended Advanced Warning Sign Spaceing: Urban (low speed) - CORRECT ANSWER -100'
Recommended Advanced Warning Sign Spaceing: urban (high speed) - CORRECT ANSWER -350'
Recommended Advanced Warning Sign Spaceing: Rural - CORRECT ANSWER -500'
CERTIFICATION QUESTIONS WITH CORRECT
ANSWERS 2025
Formula for Min. taper length - CORRECT ANSWER -L=(WS²)/60 for 40MPH or less,
L=WS for 45MPH or more
speed used in formulas should be - CORRECT ANSWER -
The off peak 85th percentile. Which is the speed at or below which 85% of vehicles travel operating s
peed in free flow conditions
Distance of L for 25 MPH with 12' Lane width - CORRECT ANSWER -125'
Distance of L for 35 MPH with 12' Lane width - CORRECT ANSWER -245'
Distance of L for 45 MPH with 12' Lane width - CORRECT ANSWER -540'
Distance of L for 55 MPH with 12' Lane width - CORRECT ANSWER -660'
Distance of L for 65 MPH 12' Lane width - CORRECT ANSWER -780'
Merging Taper Length - CORRECT ANSWER -L Minimum
Shifting Taper Length - CORRECT ANSWER -1/2 L Minimum
Shoulder Taper Length - CORRECT ANSWER -1/3 L Minimum
One-Lane, Two-Way Taper (Flagger taper) Length and number of devices - CORRECT ANSWER -50'-
100' regardless of speed
6 devices 10'-20' apart
, Downstream taper Length - CORRECT ANSWER -50'-100' per lane
Tangent distance (between tapers) - CORRECT ANSWER -2L
Tangent distance before shifting taper - CORRECT ANSWER -1/2L
Activity Area Sub-components (3) - CORRECT ANSWER -Buffer Space
Work Space
Traffic Space
Longitudinal Buffer Space - CORRECT ANSWER -Recovery Area for errant vehicles: Forgiving design
Protects workers and Motorists
Always completely empty or clear
No vehicles, truck-mounted attenuator, equipment, or materials
STRONGLY RECOMMENDED: unless there is a documented reason not to
Termination Area is:
can contain: (2) - CORRECT ANSWER -Where road users are returned to their normal path
extends from the downstream end of the work area to the last device such as end work zone sign
May contain:
end work zone sign: usually 500' past last device
downstream taper = 50'-100' per lane
Recommended Advanced Warning Sign Spaceing: Urban (low speed) - CORRECT ANSWER -100'
Recommended Advanced Warning Sign Spaceing: urban (high speed) - CORRECT ANSWER -350'
Recommended Advanced Warning Sign Spaceing: Rural - CORRECT ANSWER -500'
