ATSSA Traffic Control Supervisor Re-cer fica on (With
some basics) Complete Ques ons and answers Newest
RATED A+ 2025/2026 NEW! UPDATED
L=(WS²)/60 for 40MPH or less,
L=WS for 45MPH or more - Ans Formula for Min. taper length
The off peak 85th percen*le. Which is the speed at or below which 85% of vehicles travel
opera*ng speed in free flow condi*ons - Ans speed used in formulas should be
125' - Ans Distance of L for 25 MPH with 12' Lane width
245' - Ans Distance of L for 35 MPH with 12' Lane width
540' - Ans Distance of L for 45 MPH with 12' Lane width
660' - Ans Distance of L for 55 MPH with 12' Lane width
780' - Ans Distance of L for 65 MPH 12' Lane width
L Minimum - Ans Merging Taper Length
1/2 L Minimum - Ans Shi7ing Taper Length
1/3 L Minimum - Ans Shoulder Taper Length
, 50'-100' regardless of speed
6 devices 10'-20' apart - Ans One-Lane, Two-Way Taper (Flagger taper) Length and number of
devices
50'-100' per lane - Ans Downstream taper Length
2L - Ans Tangent distance (between tapers)
1/2L - Ans Tangent distance before shi7ing taper
Buffer Space
Work Space
Traffic Space - Ans Ac*vity Area Sub-components (3)
Recovery Area for errant vehicles: Forgiving design
Protects workers and Motorists
Always completely empty or clear
No vehicles, truck-mounted a?enuator, equipment, or materials
STRONGLY RECOMMENDED: unless there is a documented reason not to - Ans Longitudinal
Buffer Space
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
some basics) Complete Ques ons and answers Newest
RATED A+ 2025/2026 NEW! UPDATED
L=(WS²)/60 for 40MPH or less,
L=WS for 45MPH or more - Ans Formula for Min. taper length
The off peak 85th percen*le. Which is the speed at or below which 85% of vehicles travel
opera*ng speed in free flow condi*ons - Ans speed used in formulas should be
125' - Ans Distance of L for 25 MPH with 12' Lane width
245' - Ans Distance of L for 35 MPH with 12' Lane width
540' - Ans Distance of L for 45 MPH with 12' Lane width
660' - Ans Distance of L for 55 MPH with 12' Lane width
780' - Ans Distance of L for 65 MPH 12' Lane width
L Minimum - Ans Merging Taper Length
1/2 L Minimum - Ans Shi7ing Taper Length
1/3 L Minimum - Ans Shoulder Taper Length
, 50'-100' regardless of speed
6 devices 10'-20' apart - Ans One-Lane, Two-Way Taper (Flagger taper) Length and number of
devices
50'-100' per lane - Ans Downstream taper Length
2L - Ans Tangent distance (between tapers)
1/2L - Ans Tangent distance before shi7ing taper
Buffer Space
Work Space
Traffic Space - Ans Ac*vity Area Sub-components (3)
Recovery Area for errant vehicles: Forgiving design
Protects workers and Motorists
Always completely empty or clear
No vehicles, truck-mounted a?enuator, equipment, or materials
STRONGLY RECOMMENDED: unless there is a documented reason not to - Ans Longitudinal
Buffer Space
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
