Types of Taper
Taper length
Downstream taper
Downstream taper
Buffer space
Buffer space
Buffer space
Buffer space
Taper length
Taper length
Taper length
Taper length
Merge Taper: When a lane is
closed and vehicles in that lane
must merge with traffic in an
adjacent lane. The number of
lanes is reduced.
Shift Taper: There is a shift in
the path of the lanes, but the
normal number of lanes is not
reduced.
Shoulder Taper: Work is
done on the shoulder with no
or minimal encroachment
into the lane of traffic. The
shoulder is closed.
Flagger Taper: Opposing
directions of traffic share
one lane.
Table 1. Taper Lengths
Merge Taper
SPEED
MPH
20
25
30
35
40
45
50
Shift Taper
WIDTH OF LANE OFFSET
From Original Lane Width
(in feet)
8’
53’
3 (cones) 83’
10’
67’
3 (cones) 104’
12’
80’
4 (cones) 125’
3 120’
4 150’
5 180’
4 165’
5 205’
6 245’
5 215’
6 270’
7 320’
6 360’
7 450’
8 540’
10 400’
8 10 500’
10 12 600’
12 SPEED
MPH
20
25
30
35
40
45
50
Shoulder Taper
WIDTH OF LANE OFFSET
From Original Lane Width
(in feet)
8’
27’
10’
34’
12’
40’
2 (cones) 42’
2 (cones) 52’
2 (cones) 63’
2 60’
2 75’
3 90’
2 85’
3 105’
3 125’
3 110’
3 135’
4 160’
3 180’
4 225’
4 270’
4 200’
4 5 250’
5 6 300’
6 SPEED
MPH
20
25
30
35
40
45
50
WIDTH OF LANE OFFSET
From Original Lane Width
(in feet)
Minimum
taper length
in feet
2(cones) 35’
12’
27’
2 (cones) 42’
2 40’
2 50’
2 60’
Minimum #
of cones
required
2 55’
2 70’
2 85’
2 75’
2 90’
3 110’
2 120’
3 150’
3 180’
3 135’
4 170’
4 200’
3 4 4 8’
18’
2 (cones) 28’
Flagger Taper
All Speed
Minimum taper length
50 ft
Maximum taper length
100 ft
Maximum spacing
between cones
20 ft
Set Up
Pick Up
Termination
Termination
Start
Start
Advance warning
* Maximum spacing between cones is equal to speed limit (example: 35 mph = 35 feet)
Advance warning
10’
22’
Table 2. Length for Downstream Taper, Longitudinal
Buffer Space and Flagger Station Distance
SPEED
MPH
20
25
30
35
40
45
50
Downstream
Taper
Longitudinal
Buffer Space
Flagger
Stations
(in feet)
(in feet)
(in feet)
50’
2 (cones) 50’
115’
6 (cones) 155’
115’
6 (cones) 155’
2 50’
6 200’
6 200’
2 50’
7 250’
7 250’
2 50’
7 305’
7 305’
2 50’
8 360’
8 360’
2 50’
8 425’
8 425’
2 9 9 * Maximum length for downstream taper is 100 feet
* Maximum spacing for all speed on downstream taper is 20 ft
Table 3. Advance Warning Sign Spacing
ROAD TYPE
DISTANCE BETWEEN
SIGNS (in feet)
A
B
C
Urban (Low Speed)-25 mph or less
100
100
100
Urban (High Speed)-more than 25 mph
250
250
250
Urban (High Speed)-more than 40 mph
350
350
350
* Distance “A” is the distance from the transition point to
the first sign.
* Sign “A” is the first sign or sign closest to the work zone.