VEGETATION CONTROL 

FOR SAFETY

A Guide for Local Highway and Street 

Maintenance Personnel

Revised August 2008
Notice

This document is disseminated under the sponsorship 

of the Department of Transportation in the interest of 

information exchange. The United States Government 

assumes no liability for its content or use thereof.

The contents of this report reflect the views of the 

author, who is responsible for the facts and the 

accuracy of the data presented herein. The contents 

do not necessarily reflect the official policy of the 

Department of Transportation. 

This report does not constitute a manual, handbook, 

standard, specification, or regulation. 

The United States Government does not endorse 

products or manufacurers. Trademarks or 

manufacturers’ names appear herein only because they 

are considered considered essential to the objective of 

this document.
i

1. Report No. FHWA 

FHWA-SA-07-018

2. Government Accession 

No.

3. Recipient’s Catalog No.

 

4. Title and Subtitle

Vegetation Control for Safety, A Guide for Local Highway and Street Maintenance 

Personnel

5. Report Date

Revised August 2008

6. Performing Organization 

Code

 

7. Authors

Ronald W. Eck, Ph.D., P.E. and Hugh W. McGee, P.E.

8. Performing Organization 

Report No.

9. Performing Organization Name and Address 10. Work Unit No.

Vanasse Hangen Brustlin Inc

700 – 8300 Boone Boulevard

Vienna, VA 22182-2626

11. Contract or Grant No.

DTFH61-05-D-00024

12. Sponsoring Agency Name and Address

Office of Safety

Federal Highway Administration

U.S. Department of Transportation

1200 New Jersey Avenue, S.E.

Washington, D.C. 20590

13. Type of Report and Period 

Covered

Final Report

14. Sponsoring Agency Code

15. Supplementary Notes: The FHWA Office of Safety Contract Task Order Manager was Dr. Clayton Chen. The 

Technical Working Oversight Group included Michael Blankenship, Rick Hollatz, Mark Hood, Brandon Martin, and 

Jon Oshel.

16. Abstract

Vegetation, if not controlled, can present a safety hazard for several reasons. Trees close to the road can present 

a fixed object hazard. Tall grass, weeds brush and tree limbs obscure or limit a driver’s view of the road ahead, 

traffic control devices, approaching vehicles, wildlife and livestock, and pedestrians and bicycles. The purpose of 

this guide is to help local road agency maintenance workers identify locations where vegetation control is needed to 

improve traffic and pedestrian safety, to provide guidance for maintenance crews, and to make them aware of safe 

ways to mow, cut brush and otherwise control roadside vegetation..

17. Key Words

Vegetation control, safety, maintenance, sight 

distance

18. Distribution Statement

No restrictions. This document is available to the public through 

the National Technical Information Service, Springfield, VA 

22161.

19. Security Classif. (of this report)

Unclassified

20. Security Classif. (of this page)

Unclassified

21. 

No. of 

Pages: 

50

22. Price

Form DOT F 1700.7 (8-72) Reproduction of completed pages authorized
ii 

ACKNOWLEDGEMENTS

This guide was prepared by Vanasse Hangen Brustlin, Inc. (VHB) 

under FHWA contract DTFH61-05-D-00024. Ms. Leslie Wright, 

Federal Highway Administration Office of Safety, was the initial task 

order manager; she was replaced by Dr. Clayton Chen. The principal 

investigator and primary author was Dr. Ronald Eck of West Virginia 

University as a consultant to VHB. Technical editing was provided by 

Dr. Hugh McGee and Ms. Vicki Glenn and document preparation was 

performed by Ms. Michelle Scism, all from VHB.

A technical working oversight group was formed to guide the preparation 

of this document. The members included:

• Michael Blankenship, Consultant, Phoenix, AZ

• Rick Hollatz, Skamania County, WA Department of Public 

Works

• Mark Hood, Pennoni Associates, Inc., State College, PA

• Brandon Martin, City of Petersburg, VA

• Jon A. Oshel, Association of Oregon Counties, OR

• Dennis Trusty, Northern Plains Tribal Technical Assistance 

Program, Bismarck, ND
iii

TABLE OF CONTENTS

I. INTRODUCTION..............................................................1

Scope and Objectives.....................................................1

Goals of Vegetation Control.........................................1

Roadside Vegetation Management.............................2

II. SPECIFIC THINGS TO CHECK .....................................4

Sign Visibility.................................................................4

Clear Sight Lines ............................................................5

Drainage...........................................................................6

Side Road Visibility.......................................................7

Roadside Trees ...............................................................8

Winter Maintenance ....................................................11

Pedestrian Paths............................................................12

III. KEEPING TRAFFIC CONTROL DEVICES 

VISIBLE..........................................................................14

IV. STOPPING SIGHT DISTANCE ON CURVES ..........17

V. INTERSECTION SIGHT DISTANCE.........................20

VI. MOWING FOR SAFETY ................................................24

 Types of Mowing .........................................................24

 Mowing Operation Hints ...........................................25

 Traffic Control for Mowing 

 Operations .....................................................................27

VII. LEGAL ASPECTS.............................................................29

VIII.RESOURCES ON VEGETATION CONTROL FOR 

SAFETY...............................................................................32

 Publications ...................................................................32

 Videos/DVDs ................................................................33

 Websites..........................................................................33

IX. APPENDICES....................................................................35
iv 
1

I. INTRODUCTION

Scope and Objectives

Safety is a main concern of highway and street agencies. In fact, 

roadway safety cannot be achieved without a good maintenance 

program. Employees of local road agencies are responsible for 

reviewing their roads and rights-of-way, identifying hazards, and 

making conditions safer. 

One potential hazard is vegetation. Trees close to the road can 

present a fixed object hazard. Grass, weeds, brush and tree limbs 

can obscure or limit a driver’s view of traffic control devices, 

approaching vehicles, wildlife and livestock, and pedestrians and 

bicycles. Controlling vegetation helps reduce crashes and injuries.

The purpose of this guide is to help local road agency maintenance workers identify locations where vegetation control is 

needed to improve traffic and pedestrian safety, to provide 

guidance for maintenance crews, and to make them aware of 

safe ways to mow, cut brush and otherwise control roadside 

vegetation. This document is not intended to be a design guide; 

if further clarification is needed, maintenance personnel should 

consult an engineer.

Goals of Vegetation Control

The main goals of vegetation control include:

h Keeping signs visible to drivers.

h Keeping road users (vehicles, bicycles and pedestrians) 

visible to drivers.

h Improving visibility of livestock and wildlife near the 

road.

h Helping pedestrians and bicyclists see motor vehicles.

h Keeping sidewalks and pedestrian paths clear and free 

from overhanging vegetation.

h Removing trees close to the roadway which could result 

in a severe crash if hit.

h Improving winter road maintenance in snow and ice 

areas.
2 

h Helping drainage systems function as designed.

h Preserving pavements through daylighting and root 

system control.

h Controlling noxious weeds in accordance with local laws 

and ordinances.

This publication describes conditions commonly found on local 

highways and streets and how road workers can identify potential 

hazards caused by vegetation. Detailed information is presented 

about sight distances, worker safety, and setting up temporary 

traffic control. 

Roadside Vegetation Management

Roadway agencies are encouraged to develop roadside vegetation 

management programs to define the best maintenance practices 

for each location. An integrated roadside vegetation management 

program consists of eliminating or controlling vegetation 

through a variety of strategies including mowing, brush cutting 

(mechanical and hand), use of herbicides, grazing of livestock, 

cultivating desirable vegetation, and re-vegetation. 

Be sure you know your state’s laws and regulations dealing with 

vegetation control, including any record-keeping and reporting 

requirements. Consult with your local weed control specialist to 

determine the type of vegetation and the best way to control it. 

If noxious weeds are present, mowing, for example, will spread 

the seeds and spread the infestation so you have more work to 

do next year. Use of herbicides may not be permitted by local 

ordinance or a plant on the Threatened and Endangered Species 

list may be present. Different species require different treatments. 

One useful way to look at how and why vegetation control is 

needed for safety is to think in terms of Roadside Management 

Zones. The figure on the next page shows the zones and the 

objectives of each zone, as developed by the Washington State 

Department of Transportation. 
3

Roadside Management Zones and Objectives

Source: Washington State Department of Transportation
4 

II. SPECIFIC THINGS TO CHECK

Sign Visibility

Signs should be visible to drivers at all times. Maintenance patrols 

should be on the lookout for trees and brush that block the view 

of signs and other traffic control devices. Tree branches or brush 

in front of a sign can hide it from view of motorists. Right-of-way 

control signs (STOP and YIELD signs) are most critical; brush and 

tree branches in front of them should be cut immediately. It is 

important that motorist see warning and guide signs as well, so 

blocking vegetation in front of these signs should be trimmed as 

soon as possible. Suggested maintenance steps for keeping traffic 

control devices visible are presented in Section III.

 (a) (b) 

The STOP sign is not visible at all from mid-block (a) and barely visible on 

immediate approach (b).

This warning sign (circled) is only partially visible 

in the spring. By mid-summer, it will be completely 

hidden by vegetation.
5

Clear Sight Lines

Tall grass, weeds and brush 

in the shoulder, ditch and 

backslope areas of a roadside 

can create problems. Low fixed 

object hazards such as culvert 

headwalls, drainage inlets, 

guardrail ends and any object 

markers in front of them can 

be hidden by tall grass, as can 

wildlife and livestock. High 

grass can also obscure the 

shoulder. Shoulder and roadside 

maintenance such as grading 

or mowing should be done to 

define the edge of shoulder and 

ditch so that motorists can see the 

shape, condition, and limits of the 

roadside.

Well-defined shoulder and ditch allow drivers to see the shape, 

condition, and limits of the roadside. 

This object marker and culvert 

headwall are almost completely 

obscured by dense vegetation.
6 

On the inside of horizontal curves, vegetation growth close to 

the edge of pavement can block a driver’s view of motor vehicles 

(in the same or opposite direction), bicycles and pedestrians. 

Maintaining roadsides so headlights and taillights can be 

seen around the inside of horizontal curves can increase the 

horizontal sight distance available. More detailed information 

on determining how far back to trim vegetation on the insides of 

curves is presented in Section IV. 

Drainage 

Weeds, turf and sod can interfere with roadside drainage. A high 

shoulder creates a secondary ditch and damages the pavement. 

Water on the pavement due to high shoulders creates safety 

problems, including hydroplaning and isolated icy conditions 

during the winter. Grading may be necessary to make sure the 

shoulder continues the road crown smoothly. 

High shoulder due to vegetation growth on the shoulder prevents 

water from running off of the pavement, saturating the road 

base and causing safety problems such as ponded water (and ice 

in the winter).
7

Side Road Visibility

Roadway intersections increase the chances of vehicle crashes. 

Safe and efficient vehicle movement through an intersection 

requires good visibility. As drivers approach an intersection, they 

need to check each quadrant of the intersection for the presence 

of entering vehicles. Similarly, drivers pulling out from a STOP 

sign need a clear view of oncoming traffic. A clear vision triangle 

at each corner of an intersection helps drivers avoid problems. 

Factors in determining required sight triangles are discussed in 

Section V. 

Due to excessive vegetation in the corner sight triangle, drivers 

are not able to see traffic approaching from the left in time to 

enter or cross the intersection safely. 

Visibility is a particular concern at rail-highway grade crossings 

due to the severe crashes that can occur. Brush and trees should 

not be allowed to obscure the railroad tracks and any approaching 

trains. A cooperative effort of the railroad and roadway agency 

is needed. Municipalities are responsible for controlling the 

vegetation on their right-of-way and railroads are responsible for 

controlling the vegetation on their right-of-way. Due to the size 
8 

of the sight triangles at grade crossings, private property owners 

may also need to participate in vegetation control. 

Roadside Trees

One of the most common causes of fatal and serious injury crashes 

on rural roads involves vehicles leaving the road and striking a 

tree. The concept of a clear zone, an area adjacent to the traveled 

way in which slope, surface and an absence of fixed objects can 

permit recovery of a vehicle that leaves the roadway, is important 

to providing a safe roadside. The clear zone is more fully 

described in the Appendix A. 

Trees are potential hazards because of their size and location with 

respect to vehicle traffic. Trees larger than 4 inches in diameter 

can be a hazard to a vehicle. The closer trees are to the travel lane, 

the more likely a vehicle is to strike them. Isolated trees provide 

a better opportunity for removal compared to forest conditions 

where removal involves significant cost. Recognize the sensitivity 

of removing individual trees. Removal should be based on 

potential crash frequency and severity. First priority should be on 

removing trees closest to the road. Trees in critical locations such 

as curves and intersections should be considered for removal. 

Trees that have been struck deserve additional attention. 

Roadside trees are fixed object hazards for vehicles leaving the 

traveled way.
9

Trees near the road that have been struck before deserve special 

attention.

Cut trees close enough to the ground so that no stump remains 

to be a fixed object or snagging hazard. Small diameter trees 

should be cut off no more than 4 inches from the ground. Large 

diameter trees should be cut flush with the ground. Trees of any 

size growing on a slope should be cut flush with the ground. 

Snagging occurs when a vehicle undercarriage catches on a stump 

or other object. Generally, any stump higher than 4 inches above 

the surrounding ground can cause snagging. 

All trees within the clear zone should be cut while they are still 

small saplings rather than small trees. At that time, they are easy 

to cut off at ground level and cause no stump problems. Also, no 

one will be tempted to try to save a beautiful, but hazardous, tree 

in the roadway clear zone. Note that while trees close to the road 

should be removed for safety, those that also provide shade for 

waterways should be mitigated to a safer location because water 

temperature is crucial to fish habitat. Your agency should have 

a policy on planting trees within the right-of-way; for example, 

do not allow trees within the clear zone or types of roadside trees 

allowed. 
10 

Dead and leaning trees within the roadway right-of-way that 

endanger the traveling public (including those over sidewalks 

and multi-use trails) should be felled and disposed of by an 

approved method. Potentially hazardous trees outside the rightof-way should be referred to property owners for removal unless 

an emergency situation exists. Documentation is especially 

important in this regard. Be sure to keep records of when notice 

was received, the date the situation was reviewed, the date a 

letter was sent to the property owner, the date the problem was 

resolved, who resolved it and other facts of this nature. 

An opening completely through the 

tree is an indication that it has 

serious health problems. This tree 

near the road should be felled as 

soon as possible. 

The general lack of leaves 

and branches on the tree in 

the background indicates that 

this tree is diseased. The fact 

that one part of the tree is 

leaning over the sidewalk and 

road means that it should be 

felled as soon as possible. 
11

Winter Maintenance

When trees and shrubs (particularly evergreens) in the rightof-way cast shadows on the pavement, freeze-thaw cycles may 

create isolated ice patches on the pavement. Since the rest of the 

road is dry, these ice patches are not expected by drivers and can 

easily cause loss-of-control crashes. Work on the south and west 

sides of the roads first if you have limited time and money for 

brushing. “Daylighting” by cutting taller vegetation lets the sun 

help with thawing and ice control (and generally helps to preserve 

pavements). In areas receiving heavy snow, it is important to 

provide vegetation clear zones for snow storage such as illustrated 

below. 

Providing vegetation clear zones for snow storage is important in highsnowfall areas.

Another problem is dead branches overhanging roadways. As 

crews do their winter maintenance dry runs in the fall, dead limbs 

overhanging the road should be identified. These should be 

removed in the fall. When winter snow and ice accumulate on the 

dead branches, the extra weight often causes them to fall on the 

roadway/traffic. 
12 

Pedestrian Paths

Today, there is 

increased emphasis on 

walking for exercise 

and transportation. It 

is important to pay 

attention to the effects 

of vegetation on 

pedestrian safety and 

walkway accessibility. 

Just like a roadway 

corridor, a sidewalk 

corridor is made up 

of different zones as 

shown on the figure to 

the right. 

The pedestrian zone 

is specifically reserved 

for walking. The zone 

must be completely 

free of overhanging 

and protruding 

obstacles, including 

vegetation. According 

to the Americans 

with Disabilities Act 

Accessibility Guidelines

(ADAAG), objects must 

not protrude: (1) lower 

than a height of 80 

inches, (2) higher than 

27 inches from the ground, and (3) outward more than 4 inches 

from posts, buildings or free-standing fixtures. Tree branches or 

shrubs that protrude into the sidewalk corridor must be cut or 

trimmed. This means that branches between the heights of 27 to 

80 inches must be cut regularly. For people who are blind or with 

severe vision impairment and using a “white” cane, the maximum 

27-inch lower height is important. The sweep motion of the cane 

will catch the presence of the protruding object. If the object is 

Zones making up a sidewalk corridor.

Tree branches that protrude into the 

sidewalk corridor must be cut or trimmed.
13

higher than 27 inches from the ground, then the person might run 

into it and injure him/herself. 

Another sidewalk safety concern that can be caused by vegetation 

is “changes in level”. A change in level is a vertical elevation 

difference between adjacent surfaces. They can be tripping 

hazards for pedestrians and can make a walkway inaccessible to 

wheelchair users. One of the most common causes of a change 

in level in sidewalks are concrete slabs heaved up by tree roots. 

While street trees have a number of advantages, the type of tree 

should be selected carefully to minimize the root problem. Use of 

root guards should be considered in some cases. 

This change in level in the sidewalk due to tree roots creates a 

pedestrian tripping hazard and makes the sidewalk inaccessible 

to wheelchair users. 
14 

III. KEEPING TRAFFIC CONTROL DEVICES 

VISIBLE

Drivers need an unobstructed line of sight to any roadside signs or 

roadway hazards far enough ahead to allow them to react safely 

to each situation. The suggested maintenance steps are:

1. When on routine maintenance patrol, look for signs and 

other traffic control devices (including chevron signs in 

curves) blocked by brush, trees, grass, or weeds. 

Often, a small branch from an overhanging tree or bush 

near the sign is all that needs to be trimmed. If vegetation 

along the ditch or shoulder blocks a driver’s view of a 

sign, then cut enough to allow a driver sufficient time to 

see the sign and respond to its message. If your agency 

has a policy on how far from a sign vegetation has to be 

cleared for a safe view, follow that policy. If you do not 

have such a policy, Table 1 provides a suggested guideline 

that considers two groups of signs: critical signs, such 

as STOP, YIELD, ONE WAY, DO NOT ENTER, WRONG 

WAY or any sign that might require a motorist to stop, 

and all other signs. The distances for the critical signs 

are based on stopping sight distance (see table 2); the 

distances for the other signs are based on allowing 4 

seconds to detect, read, and respond to the sign. These are 

to be considered minimum distances; longer distances are 

preferable. 

Table 1. Clear Distance to See Sign

Speed Limit 

(mph)

Critical Signs 

(feet) 

Noncritical Signs 

(feet)

30 250 150

40 350 200

 50 450 250

60 600 300

2. Pull maintenance vehicle off of the traveled way and place 

temporary traffic control devices. (See Appendix F.)
15

3. Cut or trim trees, brush, weeds or grass to clear a driver’s 

line of sight to the sign or traffic control device. Always 

wear appropriate personal protective equipment as noted 

below. 

4. Watch for overhead power lines and electrified farm 

fences when cutting brush. Notify your utility company 

when crews come upon trees that are in conflict with 

power/phone lines, preventing crews from trimming. 

This way they can add it to their work list.

5. Paint the stubs of brush or small trees with a weed killer 

solution to keep it from growing back. 

6. Collect limbs and large brush to haul away for disposal or 

run them through a chipper, if available. Reclaim trees as 

mulch or bark rather than burning. 

7. Watch for moving traffic when removing the temporary 

traffic control and leaving the site. Drivers may not 

realize that you are through working and probably will 

not expect you to pull into the traffic lane. 

Take along the suggested equipment (see list on next page) when 

cutting brush or other vegetation to clear the line of sight to signs 

or other traffic control devices. Note that this list does not apply 

to spraying. 

Appendices F, G, and H of this guide contains three suggested 

temporary traffic control plans to help guide traffic around your 

work: 

h One applies (F) when all vehicles and equipment are 

off the shoulder or completely over the street curb. The 

intent in this situation is to warn drivers that you are 

working off the edge of the road. You do not want them 

to drift off the road into your work area.

h Another (G) applies to two-lane, two-way roads where a 

shoulder has to be closed for a short duration. 

h The third (H) applies when a lane may have to be 

closed when the shoulder or foreslope beyond the 

shoulder is too narrow to permit loading of trimmings or 

maneuvering equipment completely off the traveled lane. 
16 

Note that these suggested plans are not comprehensive and that 

other typical applications shown in the Manual on Uniform Traffic 

Control Devices may also be useful. 

Field Equipment List

1. Leather gloves to protect your hands from cuts and nicks and lessen 

vibration when working with power tools.

2. Safety glasses or goggles to protect your eyes from flying chips 

or particles anytime you are using brush cutters, chain saws, brush 

chippers and string trimmers.

3. Hard hat to protect your head from a falling limb or flying debris during 

cutting and clearing.

4. Safety apparel (meeting the requirements of ANSI 107 for Class 

2 risk exposure) to make you more visible to motorists.

5. Proper footwear (usually a good sturdy boot with ankle support) 

is important to protect your feet. A hardened toe cap reduces the 

chances of crushed toes.

6. Safety chaps if chain saws will be used. 

7. Chain saw, fuel and bar oil to cut large brush and small trees.

8. Gasoline-powered string trimmers to cut grass and small weeds 

away from sign supports and similar areas.

9. Brush knife or machete to cut small brush.

10. Loppers (long-handled side cutters) to cut small, low-hanging 

branches that are blocking the view of signs.

11. Tree-trimming saw with small branch lopper (on a telescoping 

pole handle) to cut higher branches from overhanging trees that are 

blocking the view of a sign.

12. Tall step ladder to help cut branches near the tree trunk to limit regrowth.

13. Axe to chop down small saplings. 
17

IV. STOPPING SIGHT DISTANCE ON CURVES

On horizontal curves, vegetation on the inside of the curve may 

restrict the driver’s line of sight. However, drivers need to be able 

to see ahead around the curve for the same stopping sight distance 

as they do at intersections. Weeds, brush or trees growing on the 

roadside on the inside of curves need to be cut so that drivers have 

adequate stopping sight distance. 

Roads are safer when drivers can see as far ahead as it takes to 

stop their vehicles. The distance it takes to notice a problem, 

realize a stop is necessary and come to a complete stop is called 

stopping sight distance. Required stopping sight distances for 

different speeds are shown in Table 2.

Table 2. Required stopping sight distances

Speed Limit 

(MPH) (or 

Design Speed)

Stopping sight distance (ft)

0% Grade Downgrades Upgrades

3% 6% 9% 3% 6% 9%

15 80 80 82 85 75 74 73

20 115 116 120 126 109 107 104

25 155 158 165 173 147 143 140

30 200 205 215 227 200 184 179

35 250 257 271 287 237 229 222

40 305 315 333 354 289 278 269

45 360 378 400 427 344 331 320

50 425 446 474 507 405 388 375

55 495 520 553 593 469 450 433

60 570 598 638 686 538 515 495

65 645 682 728 785 612 584 561

70 730 771 825 891 690 658 631

75 820 866 927 1003 772 737 704

80 910 965 1035 1121 859 817 782

Source: American Association of State Highway and Transportation Officials, A 

Policy on Geometric Design of Highways and Streets, 2004

Stopping sight distance is important along all roadways. Where 

vegetation is close to the road, special attention needs to be given 

to stopping sight distance on the inside of curves. These areas 

should be checked when vegetation growth is at its peak to make 

sure stopping sight distances are adequate. 
18 

The conventional procedure used in measuring stopping sight 

distance assumes that a driver’s eye is 42 inches above the road 

surface. The procedure also assumes that a driver must be able to 

detect an object that reaches 24 inches above the road surface on 

the road ahead. 

Sight distance is measured along the travel path of vehicles. 

Therefore, measuring for stopping sight distance will require you 

to be in the travel lane with your back to traffic. Since you and an 

assistant will stand in the travel lane, extra people will be needed 

to watch for traffic. Establishing a short-term work zone with 

flaggers will be safer. Remember, you will be measuring a section 

of road that you suspect may not offer drivers adequate sight 

distance. Be sure to wear a hard hat and safety apparel meeting 

the requirements of ANSI 107 for Class 2 risk exposure. You and 

your assistant will also need:

h Sight distance measuring sticks (described below)

h Measuring wheel and long steel tape. 

To measure sight distance, kneel in the travel lane and use a 42-

inch sighting stick to get your eyes at the proper height. Have 

your assistant move the target stick (a 42-inch long stick with the 

lower 24 inches painted a bright color to make it easier to see) in 

the travel lane until you cannot see the brightly painted section of 

the target stick or until the assistant reaches the distance shown 

in Table 2. Remember, on curves, stopping sight distance should 

be measured along the travel path of the vehicle. As shown in the 

illustration on the next page, the line of sight is shorter than the 

sight distance. You should sight along a straight line between the 

two sticks but measure the distance between the two sticks in the 

curving travel lane. 

If you can still see the bright paint on the target stick when your 

assistant reaches the stopping sight distance needed, then there is 

adequate stopping sight distance. If you lose sight of the brightly 

painted section of the target stick before your assistant reaches 

the stopping sight distance listed in Table 2, then at least some 

trimming and brush cutting is called for. 
19

Measuring for stopping sight distance.
20 

V. INTERSECTION SIGHT DISTANCE

Another important sight distance requirement that can be affected 

by vegetation is intersection sight distance. Drivers approaching 

an intersection need a clear line of sight to the intersection and 

along the crossroads early enough to see any conflicting vehicles, 

bicyclists and pedestrians to avoid a collision. Together these 

sight lines provide a sight triangle. These sight triangles can 

be limited by the presence of horizontal and/or vertical curves, 

buildings and other physical objects, and vegetation. Providing 

adequate clear sight triangles is critical for safety of all road users, 

so you want to make sure that vegetation overgrowth is not 

limiting the sight distance at intersections.

Satisfactory and hazardous sight lines at an intersection.

There are several sight distance requirements for driver 

approaching and entering an intersection which are dependent 

upon the type of intersection control—uncontrolled, yield sign, 

stop sign, or a traffic signal—and the desired maneuver—turn 

left or right or proceed straight through. Of these combinations, 

frequently found on local roads is the uncontrolled intersection, 

meaning there is no yield or stop sign or traffic signal for 

any of the legs of the intersection. For this situation, a driver 

approaching an intersection should be able to see potentially 

conflicting vehicles in sufficient time to slow down, and if 

necessary, stop before reaching the intersection; this applies 
21

for both roads. The corner sight triangle for this situation is 

determined by the length of the two legs, A and B, in the figure 

that follows. These distances are based on the vehicle speed as 

shown in Table 3. So, if road A has a speed limit of 35 mph and 

road B has a speed limit of 45 mph, the length of leg A would be 

165 feet and for leg B 220 feet. If you know that the actual speeds 

are higher, use that speed in place of the speed limit to determine 

the corner sight triangle legs.

Defining clear sight triangle at intersections.

Table 3. Required Length of Leg for No Traffic Control

Speed Limit (MPH) Length of Leg (Feet)

25 115

30 140

35 165

40 195

45 220

50 245

55 285

60 325

65 365

Source: American Association of State Highway and 

Transportation Officials, A Policy on Geometric Design of 

Highways and Streets, 2004
22 

If a driver is stopped at the intersection, then there is also a need 

for sight distance to vehicles approaching from either direction 

of the opposing road so that the stopped driver can safely turn 

left, turn right or proceed across the intersection. Of the three 

options, the sight distance needed to turn left is the longest and 

can be used to establish the required corner sight triangle for 

both legs of the minor road. These distances are shown in Table 

4 for automobiles turning left onto a two-lane, two-way roadway 

and level grades. Get the assistance of a traffic engineer if: the 

intersection approaches are on steep grades; the approaches are 

skewed; the major road has more than two lanes; or there are 

many trucks entering from the minor road. When checking the 

available sight triangle, you should position yourself about 15 feet 

back from the edge of the major-road travelway. 

Table 4. Intersection Sight Distance for Left Turn from Stop*

Speed Limit (MPH) Intersection Sight 

Distance(Feet)

25 280

30 335

35 390

40 445

45 500

50 555

55 610

60 665

65 720

Source: American Association of State Highway and Transportation 

Officials, A Policy on Geometric Design of Highways and Streets, 2004

* For passenger cars turning left onto two-lane, two-way 

roadway and level grades. 

If you find that vegetation is limiting the corner sight distance, 

then you should cut it back if it is within the public right-of-way 

lines. Usually, you are not permitted to work outside of right-ofway lines. Some municipalities have an ordinance giving them 

a sight distance easement. Such an ordinance gives maintenance 

workers the authority to ask the property owner to trim back any 

trees or shrubs blocking the corner sight triangle or to cut them. 

However, check with your supervisor before working outside 
23

of the right-of-way. No shrubs or plants within the corner sight 

triangle should be allowed to grow more than 3 feet high. 

Most private property owners are willing to cooperate in 

improving traffic safety. They should be required to keep all 

bushes and shrubs at a height of 3 feet or lower and to trim all 

trees and hanging branches to a minimum height of 7 feet. The 

Appendix includes a sample letter and attachments that could 

be used as a way of contacting property owners to ask them to 

remove vegetation blocking corner sight triangles. If notice is 

provided and homeowners do not respond in a reasonable time, 

most public agencies have the power to remove the designated 

vegetation at property owner’s expense. Check with your 

supervisor. 

For more detailed information on intersection sight distance for 

other types of intersection control (signal, stop or yield) and for 

vehicle types other than passenger vehicles consult A Policy on 

Geopmetric Design of Highways and Streets.
24 

VI. MOWING FOR SAFETY

Types of Mowing

Road and street maintenance workers do three general types 

of mowing. In order of importance, these are: safety mowing, 

transition mowing and selective mowing.

Safety Mowing:

1. Makes sure signs and other traffic control devices, 

guardrails, and other safety features can be seen.

2. Provides good intersection sight distance for drivers 

approaching intersections and driving around curves.

Transition Mowing:

1. Makes a smooth change from a narrow mowed width to a 

wide mowed width when different widths of right-of-way 

are mowed.

Contour or Selective Mowing:

1. Makes a natural blending on the maintained roadside 

with native or planted growth.

2. Shows off landscaping or wildflower areas or dresses up 

an interchange entrance to an urban area. 

The three classes of mowing are illustrated on the next page.
25

Three classes of mowing.

Mowing Operations Hints

Don’t

1. Mow too often. This wastes money, exposes mowing 

crews to traffic hazards more than needed, and can 

damage the vegetation.

2. Mow at the wrong time. Good timing reduces the 

frequency of mowing required by cutting the vegetation 

in the right stage of growth.

3. Mow too short. Leaving the proper height helps maintain 

the stand of vegetation and keeps small litter objects 

hidden.

4. Mow steep slopes if you don’t need to. Steep slopes 

increase the risk of mower accidents.

5. Mow when wet. This is hard on equipment.
26 

6. Operate equipment carelessly and scar trees and shrubs. 

Mowing is tedious but care must be taken to avoid 

accidents and preserve valuable plantings. 

Do

1. Read the operator’s manual thoroughly.

2. Protect yourself from the sun. Use the canopy on the 

mower. Wear sun screen and a hat and shirt. 

3. Strip grass from around the tree, in a circle, to help avoid 

mower wounds that can kill trees. The radius of the circle 

should be 1 to 3 feet depending on the size of the tree. 

Remove low tree branches that can click an eye or throw 

the operator off balance. 

4. Mow in the direction of oncoming traffic. This results in 

less impact if a missile is thrown out and also provides 

better visibility.

5. Ballast or weight the tractor properly.

6. Mow slopes steeper than 1:2.5 (Vertical:Horizontal) with 

a side-mounted mower on a boom if the tractor unit 

remains on flatter surfaces while mowing.

7. Operate side-mounted or boom mower units on the uphill 

side of the tractor to limit the possibility of overturning 

the tractor.

8. Be sure the mower has a roll-over protection structure 

(ROPS). Use the seat belt at all times. 

9. Replace broken or lost chain guards to deflect debris 

immediately. Using flail type mowers reduces the amount 

of debris thrown. 

10. Cover all V-belts, drive chains and power takeoff shafts.

11. Raise mowers when crossing driveways or roadways.

12. Shut off power before checking any mower unit. 

13. Block a mower before changing, sharpening or replacing a 

blade. Any blade being re-installed should be checked for 

cracks or damage that will lead to failure.

14. Check for leaks before leaving the shop.

15. Refuel away from waterways.
27

16. Keep spill kits/materials on hand in case of oil or fuel 

leaks in field.

17. Use flashing lights and Slow-Moving-Vehicle emblems 

and road signal to alert traffic. 

18. Use MOWING AHEAD or MOWING AREA signs or 

signs with similar legends to warn traffic. Signs should 

not be more than one to two miles ahead of the mowing. 

Traffic Control for Mowing Operations

Mowing is a moving operation taking place off the roadway. 

Therefore, it requires different traffic control from other 

maintenance operations. 

The most important thing to remember is to make the mower unit 

highly visible to drivers. That way, drivers will be alert to the 

mower unit and be able to avoid any potential collisions. Some 

tips include:

1. Operate rotating yellow lights on mower tractors.

2. Install Slow-Moving-Vehicle emblems on all mower 

tractors.

3. Install yellow flasher lights on roll bars on the top of 

tractor cabs and operate these at all times. 

4. Install an orange flag or pennant on a whip to show the 

location of the tractor in high grass or over the edge of 

slopes.

5. Operate the tractor with headlights on at all times. 

Warning signs such as MOWING AHEAD, ROAD WORK 

AHEAD and similar signs may be placed along the road. The 

MOWING AHEAD sign is preferred. The sign is to be used in 

advance of mowing operations on the right-of-way. Place it on the 

shoulder so that approaching drivers can read the message easily 

(2 feet off of traveled roadway).

As work progresses, move the signs so there are one to two miles 

between signs and the actual mowing work. Mount the signs on 

a breakaway portable support that will not be knocked over or 
28 

blown down easily. Cover or remove the sign during lunch break 

or any other times when work is not in progress. Do not cover or 

remove the signs if you have stopped mowing to repair or adjust 

equipment because the warning to drivers is important to safety 

operations. 
29

VII. LEGAL ASPECTS

Tort Liability—tort law applies to lawsuits in which the plaintiff 

seeks to recover money to compensate for personal injuries or 

property damage that they claim was caused by the defendant. 

In order to recover money damages from a roadway agency in a 

negligence case, the plaintiff must prove the following four things:

1. that the roadway agency owed them a duty;

2. that the roadway agency breached that duty;

3. that the roadway agency’s conduct was the proximate 

cause of the harm; and

4. and that the plaintiff was actually injured or damaged. 

In general, the law imposes on anyone carrying out an activity 

that may cause harm to others the duty to exercise ordinary care 

to avoid that harm. The law requires that we act reasonably under 

the circumstances. Failure to do so is negligence.

In most states, as part of their duty, roadway agencies must keep 

streets open for travel and free from obstructions. The failure 

to do so is negligent road/street maintenance. So for example, 

shrubbery obstructing an intersection or tree limbs blocking 

a STOP sign in the street right-of-way can be considered to be 

negligence in failing to maintain the streets in reasonably safe 

condition. 

Roadway agencies should have a risk management program with 

goals of reducing accidental injuries on streets and sidewalks 

and to increase their ability to produce evidence that they acted 

reasonably. Good records, such as when brush was trimmed, can 

be very helpful in defending against a lawsuit. The maintenance 

department should create a system that will document (1) the 

information coming into the department regarding street and 

sidewalk conditions; (2) the procedure used to prioritize the repair 

work according to the risk presented and (3) the action taken in 

making the repairs. 

Liability for failure to correct a dangerous condition may be 

imposed even if the road agency did not have actual notice of the 
30 

condition if they reasonably should have known about it. This is 

called “constructive notice.” The better and more complete the 

information regarding road and street condition, the less likely 

the issue of constructive notice is to arise. Routine inspection for 

the purpose of gathering information and identifying dangerous 

conditions can complement the records system mentioned 

earlier. A program of regular inspections should be designed 

and implemented; the inspections should be done as often as is 

reasonable under the circumstances. Maintenance crews should 

be trained to do a general inspection of the area, including 

vegetation, whenever they are sent out on a job. For example, it 

is good practice to identify and remove dead limbs, hanging over 

the road, in the fall before snow/ice or wind brings them down 

onto traffic. 

Americans with Disabilities Act (ADA)—the Americans with 

Disabilities Act is a civil rights law that prohibits discrimination 

against people with disabilities in all aspects of life. One of 

the five titles of ADA is Title II--“State and Local Government 

Services.” Government agencies must ensure that individuals 

with disabilities are not excluded from programs, services, and 

activities (pedestrian facilities). While a significant part of the 

ADA Accessibility Guidelines deals with designing facilities to 

eliminate architectural barriers such as narrow sidewalks, lack 

of curb ramps and the like, Title II also addresses maintaining

accessibility. State and local governments must maintain the 

accessible features of facilities in operable working condition. It is 

recognized that poorly maintained facilities are neither accessible 

nor safe. Examples of vegetation-related maintenance include 

correcting sidewalk slabs heaved up by tree roots and trimming 

trees/landscaping so they do not protrude into the walkway. 

Environmental Regulations—the herbicides, pesticides 

and fertilizers used in roadside vegetation management are 

substances of concern due to their potentially harmful effect 

on people, animals and the environment. There are a large 

number of regulations that govern the use, transport, storage 

and disposal of these materials. Violations of these regulations

may lead to federal, state or citizen enforcement actions that 

can result in significant penalties. It is important that roadway 

agencies be familiar with the requirements, particularly in 
31

terms of needed permits or licenses, training requirements and 

recordkeeping. Note that in addition to civil enforcement actions, 

federal and state agencies may criminally prosecute any person 

who knowingly violates certain provisions of the regulations. 

Knowledge of the requirements and good recordkeeping are the 

best defenses. 

Records should be accurate and contain the following data:

1. Date and time of application.

2. Type of equipment used (including spray curtains and 

spray shields).

3. Herbicide(s) used, including MSDS.

4. Formulation.

5. Mixing information etc.

6. Rate of application. 

7. Total area treated.

8. Location (route number, mile post or distance from 

nearest intersection, distance treated).

9. Target vegetation.

10. Weather conditions at time of application (temperature, 

humidity, wind speed and wind direction).

11. Name of applicator.

12. Miscellaneous comments (including spray pressure, 

nozzle type, nozzle size, speed at which spraying and 

distance from spray nozzle to target).
32 

VIII. RESOURCES ON VEGETATION CONTROL 

FOR SAFETY

Publications

American Association of State Highway and Transportation 

Officials, Roadside Design Guide, Washington, DC, 2006.

American Association of State Highway and Transportation 

Officials, A Policy on Geometric Design of Highways and Streets, 

Washington, DC, 2004 (contains information on determining 

required intersection sight distances).

Berger, R.L, “Integrated Roadside Vegetation Management,” 

National Cooperative Highway Research Program Synthesis 341, 

Transportation Research Board, Washington, DC, 2005. 

Clark, J.R. and Matheny, N.P., “A Handbook of Hazard Tree 

Evaluation for Utility Arborists,” International Society of 

Arboriculture, Savoy, IL, June 1993.

Federal Highway Administration, “Common Roadside 

Invasives,” brochure produced by Office of Natural and Human 

Environment, FHWA-EP-02-003, Washington, DC, 2002. 

Federal Highway Administration, Manual on Uniform Traffic 

Control Devices for Streets and Highways, Washington, DC, www.

mutcd.fhwa.dot.gov (contains current information on temporary 

traffic control, including typical applications).

Matheny, N.P. and Clark, J.R., “A Photographic Guide to the 

Evaluation of Hazard Trees in Urban Areas,” Second Edition, 

International Society of Arboriculture, Urbana, IL, 1994. 

Merullo, V.D. and Valentine, M.J., Arboriculture & the Law, 

International Society of Arboriculture, Savoy, IL, 1992.

Neuman, T.R., Pfefer, R., Slack, K.L., Hardy, K.K., Lacy, K. and 

Zegeer, C., “Guidance for Implementation of the AASHTO 

Strategic Highway Safety Plan—Volume 3: A Guide for 
33

Addressing Collisions with Trees in Hazardous Locations,” 

NCHRP Report 500, Transportation Research Board, Washington, 

DC, 2003 (electronic version available at http://transportation1.

org/safetyplan) 

Venner, M., “Control of Invasive Species,” National Cooperative 

Highway Research Program Synthesis 363, Transportation Research 

Board, Washington, DC, 2006. 

Videos/DVD’s

“Dangerous Travelers – Controlling Invasive Plants Along 

America’s Roadways,” 26-minute DVD, USDA Forest Service, 

San Dimas Technology and Development Center, San Dimas, CA, 

2006. 

“Highway Safety and Trees: the Delicate Balance,” 12-minute 

DVD, Federal Highway Administration, Washington, DC, 2006. 

“Managing Trees for Public Safety: An Arborist’s Guide,” 36-

minute videotape, International Society of Arboriculture, Savoy, 

IL, 1996.

“Managing Trees for Public Safety: The Role of Landscape 

Maintenance Personnel,” 17-minute videotape, International 

Society of Arboriculture, Savoy, IL, 1996.

“Some Mistakes Last Forever—West Virginia Logger’s Safety 

Video,” 13-minute videotape, WV Fatality Assessment and 

Control Evaluation, West Virginia University, Center for Rural 

Emergency Medicine, Morgantown, WV, February 2002. 

Websites

Federal Highway Administration, Roadside Vegetation 

Management

http://www.fhwa.dot.gov/environment/vegmgt/index.htm

International Society of Arboriculture

www.isa-arbor.com
34 

National Roadside Vegetation Management Association

www.nrvma.org

North Carolina Department of Transportation, Vegetation 

Management

http://www.ncdot.org/doh/operations/dp_chief_eng/roadside/

vegetation/maintenance/

Washington State Department of Transportation, Integrated 

Vegetation Management 

http://www.wsdot.wa.gov/maintenance/vegetation/default.htm
35

IX. APPENDICES

A. Clear Zone Description

The concept of clear zone is an approach to minimize the number 

and severity of crashes involving vehicles running off the road. 

Simply stated, it is a traversable area that starts at the edge of the 

traffic lane and extends laterally a sufficient distance to allow a 

driver to stop or return to the road before encountering a hazard 

or overturning. The traversable area would be considered safe, 

if there were no fixed objects, unless they are breakaway, and 

if the roadside geometry (either the fore slope, back slope, or 

ditch) was flat enough that a vehicle could safely traverse the 

area without tipping and rolling over. Roadside safety features 

include breakaway sign and light posts, and traversable drainage 

structures. Curbs are not considered a roadside safety feature 

since they can be easily mounted by errant vehicles; hence, their 

presence does not alter how clear zone is measured. 

A safe traversable slope can be either a recoverable slope or a 

non-recoverable slope with a clear run-out area at the bottom. A 

recoverable slope is a slope on which a motorist may, to a greater 

or lesser extent, retain or regain control of a vehicle and recover 

or stop. Slopes 1:4 (Vertical:Horizontal) or flatter are generally 
36 

considered recoverable. A non-recoverable, traversable slope is 

a slope which is considered traversable but on which an errant 

vehicle will continue to the bottom. Embankment slopes from 1:3 

and 1:4 may be considered traversable but non-recoverable if they 

are smooth and free of fixed objects. A clear run-out area is the 

flatter area at the toe of a non-recoverable slope available for safe 

use by an errant vehicle. Slopes steeper than 1:3 are not considered 

traversable and should not be found in the clear zone. 

The objective of roadside safety is to provide and maintain 

as much clear zone as practical. The design clear zone is the 

minimum width to be provided on a project and is dependent 

upon speeds, the roadside geometry, and traffic volumes. Further 

details on clear zone can be found in the Roadside Design Guide.

B. Summary of Safety Tips for Vegetation Control (Does 

Not Apply to Spraying)

1. Wear the proper Personal Protective Equipment (PPE) 

when conducting vegetation control:

h A hard hat and safety goggles to protect your 

head and eyes from injury by twigs, flying 

chips, or debris that may be kicked up.

h Leather gloves and shoes and boots with hard 

toes and hard soles.

h Safety apparel meeting the requirements of 

ANSI 107 for Class 2 risk exposure. 

2. Turn on rotating yellow lights when operating mower 

units.

3. Display a slow-moving vehicle symbol (reflective triangle) 

on the rear of a mower unit traveling on the roadway. If 

the tractor has flashing lights, turn them on to warn traffic 

that the unit is moving slowly.

4. Be alert for signs marking areas requiring limited mowing 

and vegetation control because of wildlife habitat. If these 

“no mow” areas appear to be creating a safety problem, 

report it to your supervisor for review. 

5. Face oncoming traffic as much as possible when cutting 

vegetation around object marker panels and other signs or 

safety hardware near the edge of the roadway. Stay alert 
37

at all times for out-of-control vehicles or one being driven 

too close to you.

6. Check the chain guard or other mower covers intended 

to keep debris from being thrown out of a mower before 

starting up any mower unit. Never operate a mower with 

a defective debris guard. A small rock, a piece of can or 

broken bottle thrown out from under a mower can be a 

lethal projectile.

7. Wear ear plugs, “muffs,” or other protective devices when 

operating a chain saw for any extended period of time 

and when operating a mower tractor. 

8. Wear chain-saw resistant chaps or pants when using a 

chainsaw.

C. Chain Saw Operation Checklist

h Do you inspect your saw at the beginning of each shift?

h Is your saw adjusted and used according to the 

manufacturer?

h Do you fuel your saw at least 10 feet from ignition 

sources?

h Do you start your saw at least 10 feet from the fuel 

sources?

h Do you start your saw with the chain brake on and firmly 

supported or on the ground?

h Do you keep both hands on the saw and your footing 

secure? 

h Do you clear the area of things that get in the way of 

cutting and retreating? 

h Do you avoid cutting overhead?

h Do you shut off or throttle release before you retreat?

h If the terrain is hazardous or if you are going more than 

50 feet, do you shut off or engage the chain brake?

Source: “West Virginia Logger’s Safety Field Guide,” West 

Virginia Fatality Assessment and Control Evaluation Program, 

WVU Center for Rural Emergency Medicine, Morgantown, WV, 

February 2002. 
38 

D. Mixing, Storing, Transporting and Disposing of 

Herbicides Safely

h Read the label and follow instructions exactly. Always 

use the safety equipment specified on the label.

h All measuring or mixing equipment should be thoroughly 

washed after each use and stored with the herbicides in a 

locked and secure area. 

h Carry spill kits/containment materials in spray vehicle.

h Do not load or mix herbicides near waterways. 

h Completely clean up any spills using an absorbent 

material, if needed.

h Always store herbicides in their original containers. Do 

not transfer or store herbicides in unmarked containers 

not intended for herbicide, such as soft drink bottles, jars 

or milk cartons.

h Keep herbicides in a locked, secure facility set aside and 

conspicuously posted for that purpose. 

h Do not store safety equipment with herbicides.

h Check containers frequently for leaks. Should a leak 

occur, transfer the herbicide to a marked container meant 

to hold that herbicide. Completely clean up the leak.

h Keep an inventory of all stored herbicides. 

h The name and phone number of the nearest hospital and 

poison control center should be posted in a prominent 

location in the storage facility. 

h When transporting herbicides, do not place them in the 

cab or passenger compartment. 

h Never leave a vehicle unattended with herbicide 

containers exposed.

h Always have the labels and MSDS (Material Safety Data 

Sheets) in the vehicle for the herbicides being used or 

transported. 

h Use appropriate gloves, boots, clothing and respirators as 

required by the chemical being used.

h Never use leather gloves or shoes when spraying. 

h When disposing of herbicide containers, follow the 

instructions on the label, including proper safety 

equipment and clothing. 

h Learn, keep current with and strictly adhere to laws and 

regulations regarding use and disposal of all herbicides. 
39

E. Corner Sight Distance—Sample Letter to Property 

Owner

 (Month/Day/Year)

(Property Owner)

(Address)

(City/State/Zip)

In a recent survey of your area, street maintenance crews observed 

the following problems that exist on your property.

____ Your shrubs and bushes on the corner are obstructing 

driver sight lines and must be cut down to not more than 

3 feet high (see attached drawing).

____ A tree branch hanging over the street or sidewalk limits 

view or access and must be cut to ____ feet above the 

surface of the street or sidewalk (see attached drawing).

____ A bush is obstructing the sidewalk or street and must be 

cut back to 12 inches from the edge of the sidewalk or 

curb (see attached drawing).

If you have questions, please call __________________. If you 

need help correcting the problem, the City will do the work and 

bill you for the cost. To obtain a cost estimate and authorize the 

City to do the work, call ________________ during business hours.

Thank you for your attention to this matter. We will inspect your 

property again in ____ days to check on the work unless you have 

arranged for the City to do the work before then.

Sincerely,

 _____________
40 

SIGHT OBSTRUCTION CORRECTION REPORTING

REFERENCE #: ____________________________

OBSTRUCTION ADDRESS: ____________________________

____________________________

OWNER NAME AND ADDRESS:____________________________

 ____________________________

 ____________________________

FIRST LETTER SENT DATE: ____________________________

PROBLEM: _____________________________________________

__________________________________________________________

DATE CORRECTED: ____________________________

COMMENTS OR PROBLEMS: ______________________________

__________________________________________________________

NAME: ____________________________

ADDRESS: ____________________________

____________________________

THANK YOU
41
42 
43

F. Typical Traffic Control Layout for Equipment Placed 

Off the Shoulder or Over the Street Curb

Source: MUTCD
44 

G. Typical Traffic Control Layout for Short-Duration or 

Mobile Operation on Shoulder

 

Source: MUTCD
45

H. Typical Traffic Control Layout for Lane Closure 

Source: MUTCD




Publication No. FHWA-SA-07-018

US Department of Transportation

Federal Highway Administration (FHWA)

Office of Safety

1200 New Jersey Avenue, SE 

Washington, DC 20590