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Section 3: Delineators and Chevrons

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Introduction

Road delineators and chevrons are retroreflective devices mounted near the edge of a roadway to indicate the roadway alignment. They are typically used when changes in horizontal alignment or pavement width transitions exist. They are effective aids for night driving and when either rain or snow limits the effectiveness of pavement markings.

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Delineator Design (Texas MUTCD, Section 3F.02)

Delineators consist of retroreflective material with a minimum dimension of 3 inches. Figure 8-4 indicates various delineator designs.

Delineators (click in image to see full-size image) Anchor: #ITALQJCTgrtop

Figure 8-4. Delineators

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Delineator and Object Marker Application and Spacing (Texas MUTCD, Section 3F.04)

Table 8-1 indicates the various uses for delineators for different types of roadways and roadway situations.

Anchor: #i1035998Table 8-1: Uses of Delineators and Object Markers

DELINEATOR AND OBJECT MARKER APPLICATION AND SPACING

Condition

Required Treatment

Minimum Spacing

Frwy./Exp. Tangent

RPMs

See PM-series and FPM-series standard sheets

Frwy./Exp. Curve1

Single delineators on right side

See Tables 8-3 and 8-4

Frwy./Exp. Ramp

Single delineators on at least one side of ramp (should be on outside of curves) (see Fig.8-22)

100 feet on ramp tangents. Use Tables 8-3 and 8-4 for ramp curves (“straightaway spacing” does not apply to ramp curves)

Acceleration/Deceleration Lane

Double delineators (see Fig. 8-22)

100 feet (see Fig. 8-22)

Truck Escape Ramp

Single red delineators on both sides

50 feet

Bridge Rail (steel or concrete) and Metal Beam Guard Fence

Bi-directional delineators when undivided with one lane each direction

Single delineators when multiple lanes each direction

Equal spacing (100’ max) but not less than 3 delineators

Guard Rail Terminus/Impact Head

Divided highway-Object marker on approach end

Undivided 2-lane highways - Object Marker on approach and departure end

Requires Type 3 Object Marker or reflective sheeting provided by manufacturer

Bridges with no Approach Rail

Type 3 Object Marker at end of rail and 3 single delineators approaching rail

See Fig. 8-18

Reduced Width Approaches to Bridge Rail

Type 2 Object Markers and 3 single delineators approaching bridge

See Fig. 8-17

Culverts without MBGF

Type 2 Object Markers

See Fig. 8-21

Crossovers

Double yellow delineators or RPMs

See Figures 8-11 and 8-12

Pavement Narrowing (lane merge) on Freeways/Expressway

Single delineators adjacent to affected lane for full length of transition

100 feet



1Delineators are not required in urban areas with continuous lighting.

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Use of Delineators and Chevrons in Curves

When determining if or whether delineators or chevrons are needed in curves, the posted speed limit and advisory speed limit for the curve are used. Table 8-2 shows the recommended devices to be used based upon the difference between the posted speed and advisory speed.

Anchor: #i1038785Table 8-2: Warning Devices on Curves

USE OF WARNING DEVICES AT CURVES WITH ADVISORY SPEED LIMITS

Amount by Which Advisory Speed is Less Than Posted Speed

Warning Devices Needed

5 MPH & 10 MPH

RPMs

15 MPH & 20 MPH

RPMs, Delineators and Large Arrow (W1-6) or RPMs and Chevrons

25 MPH & Greater

RPMs and Chevrons



Figures 8-6 through 8-8 illustrate the three scenarios shown in Table 8-2 for two-lane two-way roadways. In each figure, all required markings and signing are shown, as well as any optional signing. A W1-1 right angle curve or W1-2 curve warning sign is placed on the approach with the appropriate advisory speed plaque in each scenario. A supplementary W1-1a or W1-2a sign may also be installed at the beginning of the curve, but may not be used in place of the approach W1-1 or W1-2 sign. Any curve with an advisory speed of 30 mph or less requires the use of the W1-1 sign instead of the W1-2 sign. Other curve signs may be used depending on roadway geometries.

Curve Signs and Chevrons (click in image to see full-size image) Anchor: #OYBPHHQYgrtop

Figure 8-5. Curve Signs and Chevrons

Curve Treatments when Advisory
Speed is 5-10 mph Below Posted Speed (click in image to see full-size image) Anchor: #QRXJVRBHgrtop

Figure 8-6. Curve Treatments when Advisory Speed is 5-10 mph Below Posted Speed

Curve Treatments when Advisory Speed is
15-20 mph Below Posted Speed (click in image to see full-size image) Anchor: #HKBKTBXEgrtop

Figure 8-7. Curve Treatments when Advisory Speed is 15-20 mph Below Posted Speed

Curve Treatments when Advisory
Speed is 25 mph or More Below Posted Speed (click in image to see full-size image) Anchor: #GGBBAQKUgrtop

Figure 8-8. Curve Treatments when Advisory Speed is 25 mph or More Below Posted Speed

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Delineator Placement

Typically, the height of delineators is approximately 4 ft above the near edge of the pavement to the bottom of the lowest retroreflective device. Delineators are located 2-8 ft from the edge of the pavement. All delineators on a stretch of highway should be the same distance from the edge of the pavement, except where a restriction exists (such as guardrail, culvert headway, or other obstruction). Where a restriction exists, the delineators should be in line with the inner most edge of the obstruction. Figure 8-9 depicts typical delineator placement.

Typical Delineator Installation (click in image to see full-size image) Anchor: #PUISHOTNgrtop

Figure 8-9. Typical Delineator Installation

When delineators are installed further than 8 ft from the edge of the pavement, it may not be practical to provide a height of 4 ft. In this case, the delineator is installed so the reflective unit is as close to 4 ft above the surface of the pavement edge as practical.

Delineators may be attached to a vertical support. An example includes along guardrail posts or cable barrier. Figure 8-10 illustrates examples of delineators attached to guardrail posts.

Delineator Installation on Guardrail Post (click in image to see full-size image) Anchor: #RYNBWRKVgrtop

Figure 8-10. Delineator Installation on Guardrail Post

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Chevron Placement

Chevrons are placed the same distance from the edge of the traveled lane and pavement as other signs as shown in Chapter 4. They may be placed at a height of either 7.0 - 7.5 ft (with triangular slip base) or 4.0 - 4.5 ft (with wedge anchor and when size of chevron is 24" x 30" or smaller, such that height from ground to top of chevron does not exceed 6'6") measured from the edge of traveled lane to bottom of the chevron as shown in Figure 4-22.

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Delineator and Chevron Spacing

Spacing for delineators and chevrons depends on the application. However, when a driveway or intersection interrupts the selected spacing interval, the delineator or chevron should be located as close to its correct position without interfering with the driveway or intersection.

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  • Horizontal Curves - On horizontal curves, spacing should be adjusted so that several delineators or chevrons are always visible to the driver. Tables 8-3 and 8-4 illustrate spacing for delineators and chevrons on horizontal curves as well as on approaches and departures from horizontal curves.
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  • Roadside Barriers - When delineators are used in conjunction with roadside barriers (i.e., guardrail or bridge rail) on straight sections of roadway, the spacing should be adjusted to ensure a minimum of three delineators are used, with a maximum spacing of 100 ft between any two delineators. When the roadside barrier is located along a curved section, Table 8-3 or 8-4 should be used to determine the appropriate delineator spacing up to a maximum of 100 ft. Section 4 should be used for applications concerning concrete median barriers.

Other types of retroreflective devices may be used on sections of roadways with guardrail, bridge rail, or concrete barrier. See Section 4 for more information.

Anchor: #i1045450Table 8-3: Suggested Spacing for Highway Delineators and Chevrons on Horizontal Curves Based on Degree of Curve

DEGREE OF CURVE

RADIUS OF CURVE, FT

DELINEATOR SPACING IN CURVE (A), FT

DELINEATOR SPACING IN STRAIGHTAWAY (2A), FT

CHEVRON SPACING IN CURVE (B), FT

1

5730

225

450

=

2

2865

160

320

=

3

1910

130

260

200

4

1433

110

220

160

5

1146

100

200

160

6

955

90

180

160

7

819

85

170

160

8

716

75

150

160

9

637

75

150

120

10

573

70

140

120

11

521

65

130

120

12

478

60

120

120

13

441

60

120

120

14

409

55

110

80

15

382

55

110

80

16

358

55

110

80

19

302

50

100

80

23

249

40

80

80

29

198

35

70

40

38

151

30

60

30

57

101

20

40

20



Anchor: #i1046166Table 8-4: Suggested Spacing for Highway Delineators and Chevrons on Horizontal Curves Based on Advisory Speed

ADVISORY SPEED (MPH)

DELINEATOR SPACING IN CURVE (A), FT

DELINEATOR SPACING IN STRAIGHTAWAY (2A), FT

CHEVRON SPACING IN CURVE (B), FT

65

130

260

200

60

110

220

160

55

100

200

160

50

85

170

160

45

75

150

120

40

70

140

120

35

60

120

120

30

55

110

80

25

50

100

80

20

40

80

80

15

35

70

40



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Delineation for Divided Highway Intersections and Crossovers

The following delineation is typically used for divided highway intersections and crossovers:

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  • With left turn bay on approach: Use raised pavement markers (RPMs) to supplement the solid left turn lane line or a double yellow delineator on the opposite median. Figure 8-11 illustrates this application. The RPMs are placed 1 inch inside the left turn lane line and at 10 ft spacing. Use a Type II-C-R RPM. If desired, both the RPMs and double yellow delineator may be used.
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  • With no left turn bay on approach: Use double yellow delineator on far side of median opening or 4 Type I-A RPMs to supplement lane line on the approach at 20’ spacing. Figure 8-12 illustrates this application. If desired, both the double yellow delineator and RPMs may be used.

Delineation for Median Opening with Left
Turn Lane on Approach (click in image to see full-size image) Anchor: #RJLLAYHIgrtop

Figure 8-11. Delineation for Median Opening with Left Turn Lane on Approach

Delineation for Median Opening with No
Left Turn on Approach (click in image to see full-size image) Anchor: #UJBACTASgrtop

Figure 8-12. Delineation for Median Opening with No Left Turn on Approach

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