Supervisor Re-certification
The off peak 85th percentile. Which is the speed at or below
which 85% of vehicles travel operating speed in free flow
conditions - CORRECT ANSWER speed used in formulas should
be
125' - CORRECT ANSWER Distance of L for 25 MPH with 12'
Lane width
245' - CORRECT ANSWER Distance of L for 35 MPH with 12'
Lane width
540' - CORRECT ANSWER Distance of L for 45 MPH with 12'
Lane width
660' - CORRECT ANSWER Distance of L for 55 MPH with 12'
Lane width
,780' - CORRECT ANSWER Distance of L for 65 MPH 12' Lane
width
L Minimum - CORRECT ANSWER Merging Taper Length
1/2 L Minimum - CORRECT ANSWER Shifting Taper Length
1/3 L Minimum - CORRECT ANSWER Shoulder Taper Length
50'-100' regardless of speed
6 devices 10'-20' apart - CORRECT ANSWER One-Lane, Two-
Way Taper (Flagger taper) Length and number of devices
50'-100' per lane - CORRECT ANSWER Downstream taper
Length
2L - CORRECT ANSWER Tangent distance (between tapers)
1/2L - CORRECT ANSWER Tangent distance before shifting
taper
, Buffer Space
Work Space
Traffic Space - CORRECT ANSWER 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 - CORRECT ANSWER 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 - CORRECT ANSWER
Termination Area is:
can contain: (2)