ATSSA Traffic Control Supervisor Re-certification
(missing some basics) Q&A
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Terms in this set (53)
L=(WS²)/60 for 40MPH or Formula for Min. taper length
less,
L=WS for 45MPH or more
The off peak 85th speed used in formulas should be
percentile. Which is the
speed at or below which
85% of vehicles travel
operating speed in free
flow conditions
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 One-Lane, Two-Way Taper (Flagger taper) Length and
speed number of devices
6 devices 10'-20' apart
, 50'-100' per lane Downstream taper Length
2L Tangent distance (between tapers)
1/2L Tangent distance before shifting taper
Buffer Space Activity Area Sub-components (3)
Work Space
Traffic Space
Recovery Area for errant Longitudinal Buffer Space
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
Where road users are Termination Area is:
returned to their normal
path can contain: (2)
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
(missing some basics) Q&A
Save
Terms in this set (53)
L=(WS²)/60 for 40MPH or Formula for Min. taper length
less,
L=WS for 45MPH or more
The off peak 85th speed used in formulas should be
percentile. Which is the
speed at or below which
85% of vehicles travel
operating speed in free
flow conditions
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 One-Lane, Two-Way Taper (Flagger taper) Length and
speed number of devices
6 devices 10'-20' apart
, 50'-100' per lane Downstream taper Length
2L Tangent distance (between tapers)
1/2L Tangent distance before shifting taper
Buffer Space Activity Area Sub-components (3)
Work Space
Traffic Space
Recovery Area for errant Longitudinal Buffer Space
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
Where road users are Termination Area is:
returned to their normal
path can contain: (2)
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
