Attachment 1 - 101-GEN-SPACING-CHARTS.pdf
PDF 216 KB Posted
- Solicitation number
- RFP 591 260000002068 1
- Issued by
- Michigan
About this file
This is a technical spacing and work zone traffic control chart document from the Michigan Department of Transportation (MDOT) dated November 2020, establishing standardized guidelines for work zone traffic management and channelizing device placement. The document provides comprehensive tables and formulas for determining appropriate spacing distances for traffic control devices, signs, and lane tapers based on posted speed limits ranging from 25 to 70 miles per hour. It includes specifications for three primary spacing categories: Buffer Space ("B"), Distance Between Signs ("D"), and Merging Taper Length ("L"), along with guidelines for channelizing device spacing during both daytime and nighttime operations. The document also establishes maximum spacing standards for different work zone configurations, including 2-to-1 lane road tapers, shoulder tapers, and shifting tapers, with specific minimum requirements varying based on speed limits above or below 45 miles per hour.
The document further details roll-ahead distance guidelines for traffic management area (TMA) vehicles at two test levels, specifying minimum safe distances ranging from 25 to 175 feet depending on TMA vehicle weight classifications and prevailing speed conditions prior to work zones. These specifications are calculated using standardized impact vehicle weights of 4,410 pounds for Test Level 2 and 10,000 pounds for Test Level 3, ensuring protective buffers for highway workers and traffic management personnel. The chart includes a sign border key indicating whether existing signs require coverage (solid outlines) or removal (dashed outlines), providing essential visual reference standards for contractors and project managers implementing work zone traffic control on state and local transportation projects.
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Text version
NOT TO SCALE
FILE:
Michigan Department of Transportation
NOV 2020
"B", "D" AND "L" TABLES
CHANNELIZING DEVICE SPACING,
SIGN BORDER KEY, AND ROLL-AHEAD SPACING
DATE:
SHEET:
101-GEN-SPACING-CHARTS.dgn
WORK ZONE TRAFFIC CONTROL TYPICAL
SPACING-CHARTS
101-GEN-
NO:
DISTANCE BETWEEN TRAFFIC SIGNS, "D"
POSTED SPEED LIMIT, MPH (PRIOR TO WORK AREA)
D (FEET)
DISTANCES
"D"
B (FEET)
GUIDELINES FOR LENGTH OF LONGITUDINAL BUFFER SPACE, "B"
LENGTHS
"B"
30 35 40 45 50 55 60 65 70
25 30 35 40 45 50 55 60 65 70
250 300 350 400 450 500 550 600 650 700
SPEED, MPH (PRIOR TO WORK AREA)
132 181 230 279 329 411 476 542 625
OPERATING SPEED.
* POSTED SPEED, OFF-PEAK 85TH PERCENTILE SPEED PRIOR TO WORK STARTING, OR THE ANTICIPATED
POSTED SPEED LIMIT, MPH (PRIOR TO WORK AREA)
25 30 35 40 45 50 55 60 65 70
1 11
2 100 110 120 130 140
3 135 150 165 180 195 210
4 107 180 200 220 240 260 280
5 103 134 225 250 300 325 350
6 123 160 270 300 330 360 390 420
7 143 187 315 350 385 420 455 490
8 164 214 360 400 440 480 520 560
(FEET)
OFFSET
MINIMUM MERGING TAPER LENGTH, "L" (FEET)
9 184 240 405 450 495 540 585 630
10 205 267 450 500 550 600 650 700
11 225 294 495 550 605 660 715 770
12 180 245 320 540 600 660 720 780 840
13 266 347 585 650 715 780 845 910
14 286 374 630 700 770 840 910 980
15 307 400 675 750 825 900 975 1050
15 21 27 45 50 55 60 65 70 75
90544130
32 45 62 80
42 60 82
53 75 275
63 90
33 83
Michigan Department of Transportation
NOV 2020
"B", "D" AND "L" TABLES
CHANNELIZING DEVICE SPACING
SIGN BORDER KEY AND ROLL-AHEAD SPACING
SPACING-CHARTS
101-GEN-
NO:
SHOWN IN THE ABOVE TABLES ARE AS FOLLOWS:
MERGING TAPER IN DERIVING THE "L" VALUES
THE FORMULAS FOR THE MINIMUM LENGTH OF A
60 THE WORK AREA IS 40 MPH OR LESS
WHERE POSTED SPEED PRIOR TO "L" = W X S
THE WORK AREA IS 45 MPH OR GREATER
WHERE POSTED SPEED PRIOR TO "L" = W X S
W = WIDTH OF OFFSET
S = POSTED SPEED LIMIT IN MPH PRIOR TO WORK AREA
L = MINIMUM LENGTH OF MERGING TAPER
UPSTREAM TAPERS
DOWNSTREAM TAPERS
TAPER LENGTHTYPES OF TAPERS
100' - MAXIMUM2 TO 1 LANE ROAD TAPER
1/3 L - MINIMUMSHOULDER TAPER
1/2 L - MINIMUMSHIFTING TAPER
L - MINIMUMMERGING TAPER
MAXIMUM SPACING FOR CHANNELIZING DEVICES
SPEED LIMIT
WORK ZONE
TAPERTAPER TANGENT TANGENT
< 45 MPH
> 45 MPH 25 FEET100 FEET50 FEET
1 x SPEED LIMIT 2 x SPEED LIMIT
100' (PER LANE)(USE IS RECOMMENDED)
DRUM AND 42" DEVICE SPACING (FT) NIGHTTIME 42" DEVICE SPACING (FT)
25 FEET 50 FEET
50 FEET
EXITEXIT
IS TO BE PLACED ON THE PROJECT
SOLID OUTLINES INDICATE A SIGN THAT
EXISTS ON SITE, AND NEEDS TO BE COVERED.
DASHED OUTLINES INDICATE A SIGN THAT
SIGN OUTLINE KEY
Michigan Department of Transportation
NOV 2020
"B", "D" AND "L" TABLES
CHANNELIZING DEVICE SPACING
SIGN BORDER KEY AND ROLL AHEAD SPACING
SPACING-CHARTS
101-GEN-
NO:
TO WORK ZONE)
(POSTED SPEED PRIOR
PREVAILING SPEED
25 FT
GUIDELINES FOR ROLL-AHEAD DISTANCES FOR TMA VEHICLES - TEST LEVEL 2
VEHICLE
TMA
WEIGHT OF
40 MPH OR LESS
(STATIONARY)
5.5 TONS
TO WORK ZONE)
(POSTED SPEED PRIOR
PREVAILING SPEED
50-55 MPH
100 FT
150 FT
175 FT
VEHICLE
TMA
WEIGHT OF
* ROLL-AHEAD DISTANCES ARE CALCULATED USING A 4,410 POUND IMPACT VEHICLE WEIGHT.
25 FT
25 FT
50 FT
(STATIONARY)
12 TONS
(MOBILE)
5 TONS
45 MPH
60-75 MPH
45 MPH
50-55 MPH
60-75 MPH
TMA VEHICLE TO WORK AREA)
(DISTANCE FROM FRONT OF
ROLL-AHEAD DISTANCE*
TMA VEHICLE TO WORK AREA)
(DISTANCE FROM FRONT OF
ROLL-AHEAD DISTANCE*
* ROLL-AHEAD DISTANCES ARE CALCULATED USING A 10,000 POUND IMPACT VEHICLE WEIGHT.
GUIDELINES FOR ROLL-AHEAD DISTANCES FOR TMA VEHICLES - TEST LEVEL 3
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