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Section 2: Warning Sign Advance Placement

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Introduction

Warning signs are placed in advance of a potential hazard. The Texas MUTCD presents basic information in Table 2C-4 of the manual. The information in this section expands upon the information in the Texas MUTCD.

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Advance Placement Condition Descriptions

The placement of a warning sign is based on the potential hazard the sign warns of and the amount of advance warning needed by a road user. There are two placement conditions:

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  • Condition A represents a situation that involves a complex driving decision, often in heavy traffic conditions. Lane changes in heavy traffic, exiting maneuvers, and merging traffic are common examples. This condition typically applies to freeways and high volume urban arterial situations that require additional response time.
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  • Condition B represents a condition where a vehicle may have to stop or slow down as a result of the potential hazard identified by the warning sign.
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Relation Between Minimum Distances and Sign Crew Field Book Distance

The minimum advance placement distances for warning signs shown in the next subsection are intended primarily for installation of isolated warning signs. When a warning sign is installed as part of a series of signs, it may be appropriate to place a warning sign further from the potential hazard than the values indicated in the table. In particular, warning signs on the approach or departure from an intersection are placed using the distances shown in the figures in Chapters 5 and 6 to maintain the system perspective with all the signs on the approach or departure.

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Advance Placement Distance for Warning Signs

Warning signs are placed in advance of a potential hazard based on the roadway speed limit, the type of response needed (the condition), and the speed associated with the warning sign response. Table 2-1 presents the minimum advance placement distances for warning signs. This table is an expansion of the information in Table 2C-4 from the Texas MUTCD, including speed limits of 80 and 85 mph, as well as advisory speeds ending in 5 (i.e. 15). Table 2-2 provides a description of each condition and information about which warning signs are associated with each condition.

Anchor: #i1147556Table 2-1: Minimum Advance Placement Distance for Warning Signs

Minimum Advance Placement Distance1 (ft)

Posted Speed or 85th Percentile (mph)

Condition B: Deceleration to the listed advisory speed (mph) for the condition

Condition A: Speed reduction and lane changing in heavy traffic2

B: Stop3

54

104

154

204

254

304

354

404

454

504

554

604

654

704

754

804

20

225

1006

NA5

NA5

NA5

25

325

1006

NA5

NA5

NA5

NA5

30

460

1006

NA5

NA5

NA5

NA5

NA5

35

565

1006

NA5

NA5

NA5

NA5

NA5

NA5

40

670

125

1006

1006

1006

1006

NA5

NA5

NA5

45

775

175

125

125

125

1006

1006

1006

NA5

NA5

50

885

250

200

200

200

175

150

125

1006

1006

NA5

55

990

325

275

275

275

225

225

200

150

125

1006

NA5

60

1,100

400

350

350

350

325

300

275

225

200

150

1006

1006

65

1,200

475

450

450

425

400

400

350

325

275

225

200

125

1006

70

1,250

550

525

525

525

500

475

450

425

375

325

275

225

150

1006

75

1,350

650

625

625

625

600

575

550

500

475

425

375

325

250

200

1006

80

1,475

750

750

725

725

700

675

650

600

575

525

475

425

350

300

225

150

85

1,575

850

850

850

825

800

775

750

725

675

625

575

525

475

400

325

250

150

1The distances are adjusted for a sign legibility distance of 180 feet for Condition A. The distances for Condition B have been adjusted for a sign legibility distance of 250 feet, which is appropriate for an alignment warning symbol sign. For Conditions A and B, warning signs with less than 6-inch legend or more than four words, a minimum of 100 feet should be added to the advance placement distance to provide adequate legibility of the warning sign.

2Typical conditions are locations where the road user must use extra time to adjust speed and change lanes in heavy traffic because of a complex driving situation. Typical signs are Merge and Right Lane Ends. The distances are determined by providing the driver a PRT of 14.0 to 14.5 seconds for vehicle maneuvers (2004 AASHTO Policy, Exhibit 3-3, Decision Site Distance, Avoidance Maneuver E) minus the legibility distance of 180 feet for the appropriate sign.

3Typical condition is the warning of a potential stop situation. Typical signs are Stop Ahead, Yield Ahead, Signal Ahead, and Intersection Warning signs. The distances are based on the 2004 AASHTO Policy, Exhibit 3-1, Stopping Site Distance, providing a PRT of 2.5 seconds, a deceleration rate of 11.2 feet/second2 minus the sign legibility distance of 250 feet.

4Typical conditions are locations where the road user must decrease speed to maneuver through the warned condition. Typical signs are Turn, Curve, Reverse Turn, or Reverse Curve. The distance is determined by providing a 2.5 second PRT, a vehicle deceleration rate of 10 feet/second2 minus the sign legibility distance of 250 feet.

5No suggested distances are provided for these speeds, as the placement locations are dependent on site conditions and other signing. An alignment warning sign may be placed anywhere from the point of curvature up to 100 feet in advance of the curve. However, the alignment warning sign should be installed in advance of the curve and at least 100 feet from any other signs.

6The minimum advance placement distance is listed as 100 feet to provide adequate spacing between signs.



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Conditions Associated with Specific Warning Signs

Table 2-2 lists the signs that are associated with the two conditions (A and B) used in Table 2-1. Condition B is separated into warning signs that require a stop, and warning signs that require a speed reduction. Two other conditions are included that do not pertain to Table 2-1: warning signs that do not require a speed reduction, and warning signs that are placed at the road hazard.

Anchor: #i1169576Table 2-2: Warning Sign Placement Conditions

Condition

Applicable Warning Signs

A: Complex Maneuver

W4-1, Merging Traffic

W4-1aT, Thru Traffic Merge Right (Left)

W4-2, Lane Ends

W4-5, Entering Roadway Merge

W9-1, Right (Left) Lane Ends

W9-2T, Lane Ends Merge Left (Right)

B: Stop

W2-1, Cross Road

W2-1aT, Highway Intersection Ahead

W2-2, Side Road (perpendicular)

W2-3, Side Road (oblique)

W2-4, T-intersection symbol

W2-5, Y-intersection symbol

W2-6, Circular intersection

W2-6aT, Traffic Islands Ahead

W2-7, Offset Side Road

W2-8, Double Side Road

W3-1, Stop Ahead

W3-2, Yield Ahead

W3-3, Signal Ahead

W3-4, Be Prepared to Stop

W3-6, Draw Bridge

W3-7, Ramp Meter Ahead

W3-7aT, Ramp Signal Ahead

W3-8, Ramp Metered When Flashing

W5-3, One Lane Bridge

W8-6, Truck Crossing

W8-13aT, Bridge May Ice in Cold Weather

W8-14, Fallen Rocks

W8-18, Road May Flood

W8-18aT, Water Crossing

W8-18bT, When Flooded Turn Around Don’t Drown

W10-1, Grade Crossing Advance Warning

W10-2, Parallel Railroad Crossing (cross road)

W10-3, Parallel Railroad Crossing (side road)

W10-4, Parallel Railroad Crossing (T road)

W10-4a & W10-4b, Train When Flashing

W10-5, Low Ground Clearance

W10-11, Railroad T Crossing

W10-12, Railroad Skewed Crossing

W11-1, Bicycle Crossing

W11-2, Pedestrian Crossing

W11-3, Deer Crossing

W11-4, Cow Crossing

W11-5 & W11-5a, Farm Vehicle

W11-6, Snowmobile Crossing

W11-7, Equestrian Crossing

W11-8, Fire Station

W11-9, Handicapped Crossing

W11-10, Truck Crossing

W11-11, Golf Cart Crossing

W11-12T, Watch for Emergency Vehicles

W11-12aT, Emergency Vehicles Entering Intersection When Flashing

W11-14, Horse Drawn Vehicle Crossing

W11-15, Bicycle-Pedestrian Crossing

W11-15a & W11-15b, Trail Crossing

W11-16, Bear Crossing

W11-17, Sheep Crossing

W11-18, Bighorn Sheep Crossing

W11-19, Donkey Crossing

W11-20, Elk Crossing

W11-21, Moose Crossing

W11-22, Wild horse Crossing

W11-25T, Ducks Crossing

W11-26aT, Watch for Pelicans

W11-26T, Pelicans

W12-2, Low Clearance

W12-5T, Load Zoned Bridge

W14-1T, Road Ends

W15-1, Playground

W17-3T, Loose Livestock

W17-5T, Hospital

W17-6T, Military Entrance

W17-7T, Military Area

W17-11T, Rock Slides

W17-12T, Earth Slides

W17-14T, Watch for Smoke on Road

W17-15T, Watch for Mud on Road

W20-3TD, Inspection Station Ahead

S3-1, School Bus Stop Ahead

S3-2, School Bus Turn Ahead

B: Decelerate to Indicated Advisory Speed

All warning signs with an advisory speed plaque

W1-11T, Curve Blocks View

W1-13, Truck Rollover

W3-5, S4-5, & S4-5a, Speed Reduction (use speed shown in sign as advisory speed)

W7-6, Hill Blocks View

W13-2, Exit Speed

W13-3, Ramp Speed

W13-5T, Curve Speed

W13-6, Exit Curve 25MPH

W13-7, Ramp Curve 25MPH

W13-8T, XXMPH When Flashing

W17-1, Speed Hump

N/A: No Speed Reduction

W1-1, Turn

W1-2, Curve

W1-3, Reverse Turn

W1-4, Reverse Curve

W1-5, Winding Road

W1-10 Series, Curve-Intersection

W1-11, Hairpin Curve

W4-3, Added Lane

W4-6, Entering Roadway Added Lane

W5-1, Road Narrows

W5-2, Narrow Bridge

W6-1 & W6-1aT, Divided Highway

W6-1bT, Divided Road

W6-2 & W6-2aT, Divided Highway Ends

W6-2bT, Divided Road Ends

W6-3, Two-Way Traffic

W6-3aT, Two-Way Traffic on a Three-Lane Road

W7-1, Hill

W7-1a, Hill with Grade

W8-1, Bump

W8-2, Dip

W8-3, Pavement Ends

W8-4, Soft Shoulder

W8-5aT, Slow Down on Wet Road

W8-7, Loose Gravel

W8-7aT, Loose Sand

W8-8, Rough Road

W8-9, Low Shoulder

W8-9aT, Shoulder Drop Off

W8-11, Uneven Lanes

W8-12, No Center Line

W8-15, Grooved Pavement

W8-16, Metal Bridge Deck

W8-17, Shoulder Drop Off

W8-21, Gusty Winds Area

W8-23, No Shoulder

W8-25, Shoulder Ends

W10-6, Uneven Tracks

W10-8, Trains May Exceed 80MPH

W10-9, No Train Horn

W11-15cT, Watch for Slow Moving Vehicles

W17-2T, Rumble Strips

W17-4T, Cattle Guard

W17-9T, Hitchhikers May Be Escaping Inmates

W17-10T, Watch for Low Flying Aircraft

W18-1, No Traffic Signs

W19-3, Freeway Ends

W19-5, All Traffic Must Exit

W23-2, New Traffic Pattern Ahead

N/A: Sign at Hazard

W1-1a & W1-2a, Combination Horizontal Alignment/Advisory Speed

W1-6, One Direction Large Arrow

W1-7 & W1-7T, Two Direction Large Arrow

W1-8, Chevron Alignment

W1-9T, One Direction Large Arrow

W8-19, Flood Gauge

W12-1, Double Arrow

W12-2a, Low Clearance

W14-1 & W14-1a, Dead End

W14-2 & W14-2a, No Outlet

W14-3, No Passing Zone



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