ATSSA Traffic Control Supervisor
Re-certification Questions and
Answers | 2026 Ultimate Final Review
| Grade A+
• L=(WS²)/60 for 40MPH or less,
L=WS for 45MPH or more -✓✓Formula for Min. taper length
• The off peak 85th percentile. Which is the speed at or below which 85% of vehicles
travel operating speed in free flow conditions -✓✓speed used in formulas should be
• 125' -✓✓Distance of L for 25 MPH with 12' Lane width
• 245' -✓✓Distance of L for 35 MPH with 12' Lane width
• 540' -✓✓Distance of L for 45 MPH with 12' Lane width
• 660' -✓✓Distance of L for 55 MPH with 12' Lane width
• 780' -✓✓Distance of L for 65 MPH 12' Lane width
• L Minimum -✓✓Merging Taper Length
• 1/2 L Minimum -✓✓Shifting Taper Length
• 1/3 L Minimum -✓✓Shoulder Taper Length
• 50'-100' regardless of speed
6 devices 10'-20' apart -✓✓One-Lane, Two-Way Taper (Flagger taper) Length and
number of devices
• 50'-100' per lane -✓✓Downstream taper Length
• 2L -✓✓Tangent distance (between tapers)
• 1/2L -✓✓Tangent distance before shifting taper
• Buffer Space
Work Space
Traffic Space -✓✓Activity Area Sub-components (3)
, • 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 -
✓✓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
downstream taper = 50'-100' per lane -✓✓Termination Area is:
can contain: (2)
• 100' -✓✓Recommended Advanced Warning Sign Spaceing: Urban (low speed)
• 350' -✓✓Recommended Advanced Warning Sign Spaceing: urban (high speed)
• 500' -✓✓Recommended Advanced Warning Sign Spaceing: Rural
• 1000', 1500', and 2640' -✓✓Recommended Advanced Warning Sign Spaceing:
freeways and expressways (3)
• 1 Mile
50%
shoulder at beginning of taper if possible, if not, as close to beginning as possible inside
taper. -✓✓Arrow board visibility distance by design:
night time dimming:
location:
• taper: not to exceed distance in feet = to posted speed limit
tangent: distance = double posted speed limit -✓✓device spacing taper:
tangent:
• A: Low intensity flashing
B: High-intensity flashing
C: Steady Burn
D: 360° steady burn -✓✓Warning lights types:
Type A:
Type B:
Type C:
Type D:
Re-certification Questions and
Answers | 2026 Ultimate Final Review
| Grade A+
• L=(WS²)/60 for 40MPH or less,
L=WS for 45MPH or more -✓✓Formula for Min. taper length
• The off peak 85th percentile. Which is the speed at or below which 85% of vehicles
travel operating speed in free flow conditions -✓✓speed used in formulas should be
• 125' -✓✓Distance of L for 25 MPH with 12' Lane width
• 245' -✓✓Distance of L for 35 MPH with 12' Lane width
• 540' -✓✓Distance of L for 45 MPH with 12' Lane width
• 660' -✓✓Distance of L for 55 MPH with 12' Lane width
• 780' -✓✓Distance of L for 65 MPH 12' Lane width
• L Minimum -✓✓Merging Taper Length
• 1/2 L Minimum -✓✓Shifting Taper Length
• 1/3 L Minimum -✓✓Shoulder Taper Length
• 50'-100' regardless of speed
6 devices 10'-20' apart -✓✓One-Lane, Two-Way Taper (Flagger taper) Length and
number of devices
• 50'-100' per lane -✓✓Downstream taper Length
• 2L -✓✓Tangent distance (between tapers)
• 1/2L -✓✓Tangent distance before shifting taper
• Buffer Space
Work Space
Traffic Space -✓✓Activity Area Sub-components (3)
, • 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 -
✓✓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
downstream taper = 50'-100' per lane -✓✓Termination Area is:
can contain: (2)
• 100' -✓✓Recommended Advanced Warning Sign Spaceing: Urban (low speed)
• 350' -✓✓Recommended Advanced Warning Sign Spaceing: urban (high speed)
• 500' -✓✓Recommended Advanced Warning Sign Spaceing: Rural
• 1000', 1500', and 2640' -✓✓Recommended Advanced Warning Sign Spaceing:
freeways and expressways (3)
• 1 Mile
50%
shoulder at beginning of taper if possible, if not, as close to beginning as possible inside
taper. -✓✓Arrow board visibility distance by design:
night time dimming:
location:
• taper: not to exceed distance in feet = to posted speed limit
tangent: distance = double posted speed limit -✓✓device spacing taper:
tangent:
• A: Low intensity flashing
B: High-intensity flashing
C: Steady Burn
D: 360° steady burn -✓✓Warning lights types:
Type A:
Type B:
Type C:
Type D:
