Speed Management 

A Manual for Local Rural Road Owners

U.S. Department of Transportation

Federal Highway Administration

http://safety.fhwa.dot.gov

FHWA-SA-12-027
Quality Assurance Statement

The Federal Highway Administration (FHWA) provides highquality information to serve Government, industry, and the public 

in a manner that promotes public understanding. Standards and 

policies are used to ensure and maximize the quality, objectivity, 

utility, and integrity of its information. FHWA periodically reviews 

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continuous quality improvement.

Notice

This document is disseminated under the sponsorship of the 

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exchange. The United States Government assumes no liability 

for its contents or use thereof.
Technical Report Documentation Page

1. Report No.

FHWA-SA-12-027

2. Government Accession No. 3. Recipient’s Catalog No.

4. Title and Subtitle 5. Report Date

Speed Management: A Manual for Local Rural Road 

Owners

November 2012

6. Performing Organization Code

7. Author(s)

Jeffrey Bagdade, Dan Nabors, Hugh McGee, Richard 

Miller and Richard Retting

8. Performing Organization Report 

No.

9. Performing Organization Name and Address 10. Work Unit No. (TRAIS)

Vanasse Hangen Brustlin, Inc. (VHB)

8300 Boone Boulevard, Suite 700

Vienna, VA 22182

11. Contract or Grant No.

DTFH61-10-D-00022, T-10-002

12. Sponsoring Organization Name and Address

Office of Safety

Federal Highway Administration

1200 New Jersey Ave, SE

Washington, D.C. 20590-9898

13. Type of Report and Period Covered

14. Sponsoring Agency Code

HSST

15. Supplementary Notes

Task Manager for this document was Rosemarie Anderson, FHWA Office of Safety. The Technical 

Oversight Working Group included: Carla Anderson (Kansas DOT), Alberto Figueroa (University of 

Puerto Rico), Linda Guin (FHWA), Hillary Isebrands (FHWA), Tracie Leix (Michigan DOT), Albert 

Letzkus (Pima County, AZ), Kevin McCarthy (City of Farmington Hills, MI), Reza Moghissi (Sacramento County, CA), Kevin Murphy (Delaware Valley Regional Planning Commission), Wil Price (NHTSA), 

Stephen Ratke (FHWA), Keith Williams (FHWA), and Guan Xu (FHWA). Images were provided by 

Dan Nabors, Elissa Goughnour, Ted Graef, Richard Drdul, Lee Rodegerdts, Simon St.Laurent, and 

Opus International Consultants.

16. Abstract

In 2010, 35 percent of the 30,196 fatal crashes on U.S. roadways occurred on local rural roads, with 

nearly one-third (3,427) of these involving speeding. This document is intended to provide local 

road practitioners with information on how to address speeding-related crashes through the implementation of a comprehensive Speed Management Program. An effective program addresses

all factors that influence speeding through engineering, enforcement, education, and emergency 

services—known as the four E’s of safety.

17. Key Words 18. Distribution Statement

Speed, Speeding, Speed Management, Local, 

Rural, Speed Study, Low Cost Safety Countermeasures

No restrictions.

19. Security Classification (of 

this report)

20. Security Classification (of 

this page)

21. No. of 

Pages

22. Price

Unclassified Unclassified 62 NA

Speed Management Guidebook | i

Table of Contents

1 Introduction ������������������������������������������������������������������������������������������������1

1.1 Background 1

1.2 Purpose 2

1.3 Speed Management Program 3

1.4 Agency Partnerships 5

2 Identify Speeding Issues ������������������������������������������������������������������������������7

2.1 Data Sources 7

2.2 Assessing Speeding 9

3 Identifying Countermeasures��������������������������������������������������������������������� 15

3.1 Engineering 15

3.2 Enforcement 22

3.3 Education 26

4 Implementing Countermeasures���������������������������������������������������������������� 29

4.1 Preparing for Implementation 29

4.2 Evaluate Progress 31

5 Summary��������������������������������������������������������������������������������������������������� 35

Appendix: How to Conduct a Speed Study ���������������������������������������������������A-1

List of Tables

Table 1. Example Project Ranking System. 30

Table 2. Length of Measured Zone per Speed Limit. A-2

Table 3. Speed of Vehicle Over Distance for Various Times. A-3
ii | Speed Management Guidebook 

List of Figures

Figure 1. Speed Management Program Process. 4

Figure 2. Graphical Depiction of 85th Percentile Speed. 12

Figure 3. Road Diet Comparison. 18

Figure 4. Blank Speed Survey Field Sheet. A-4

Figure 5. Sample Speed Survey Field Sheet. A-5

Figure 6. Graphical depiction of 85th percentile speed. A-6
Speed Management Guidebook | 1

1 Introduction

1.1 Background 

Speeding is defined as exceeding posted speed limits or driving too fast for 

conditions. This is a behavior that some drivers engage in without recognizing 

the risks or seriously considering the consequences. According to the National 

Highway Traffic Safety Administration (NHTSA), the consequences of excessive 

speed include the following: 1

• Greater potential for loss of vehicle control, which may result in a crash.

• Reduced effectiveness of occupant protection equipment.

• Increased stopping distance after the driver perceives a danger.

• Increased degree of crash severity leading to more fatalities and 

disabling injuries.

• Unexpected economic and even psychological implications of a speedrelated crash.

• Increased fuel consumption and cost.

The most serious consequences of speeding are the fatalities and serious 

injuries that result from crashes. Over the last ten years, speeding has been 

consistently identified as a contributing factor in nearly one-third of all roadway 

fatalities nationwide. Crashes involving speeding occur on all road types but 

are particularly prevalent on the local rural road system. The local road system 

refers to locally owned and maintained roads in rural areas. Of the 30,196 fatal 

crashes occurring on all road types in 2010, 35.4 percent—or 10,689—occurred 

on local rural roads, with nearly one-third (3,427) of these involving speeding.2

As the speed increases, the likelihood of a crash resulting in a serious injury or 

fatality also increases.

Addressing this safety issue can be a challenge for local roadway agencies 

because of their limited resources. Nonetheless, all agencies, regardless of 

size and resources, can develop a comprehensive and coordinated program to 

address speeding.

1 Strategies for Distributing “Speed Shatters Life” Campaign Public Service Advertising 

Materials (2011). http://www.nhtsa.gov/DOT/NHTSA/Traffic%20Injury%20Control/

Articles/Associated%20Files/strateg.pdf

2 Fatality Analysis Reporting System (FARS), National Highway Traffic Safety 

Administration, 2010 Data.
2 | Speed Management Guidebook 

1.2 Purpose

This document provides 

information on how to develop 

a Speed Management Program 

that is tailored to meet the needs 

of local rural road practitioners. 

A Speed Management Program 

can be effective in lowering the 

number of speeding crashes 

and the resulting fatalities and 

serious injuries on local rural 

roads. This document describes 

the various elements of a 

Speed Management Program, 

including the principles of setting 

speed limits appropriate for 

roads within the jurisdiction 

and various countermeasures 

that are effective in mitigating 

speeding as it relates to roadway 

safety in rural areas.3

The intended audience is 

comprised of the local rural 

practitioners who have 

responsibility for the operation 

and maintenance of their road 

network and the safety of its 

users. This manual provides basic 

information to assist local road practitioners in assessing speeding problems and 

developing appropriate countermeasures. It is not, however, a comprehensive 

discussion of all aspects of speeding and speed management, and, therefore, 

local practitioners should seek technical advice from their State Department 

of Transportation (DOT), Governor’s Highway Safety Office (GHSO), or Local 

or Tribal Technical Assistance Program (LTAP or TTAP). The Federal Highway 

Administration’s (FHWA’s) Office of Safety Web site lists numerous resources 

3 Donnell, E., et al., Speed Concepts.: Informational Guide, FHWA Office of Safety (2009), 

http://safety.fhwa.dot.gov/speedmgt/ref_mats/fhwasa10001/

The following terms are commonly used 

in speed literature and discussions.3

Design Speed – the speed established as 

part of the geometric design process for 

a specific roadway.

Operating Speed – the speeds at 

which vehicles are observed operating 

during free flow conditions. Free flow 

conditions occur when vehicles are 

unimpeded by traffic control devices 

(e.g. traffic signals) or other vehicles in 

the traffic stream.

Posted Speed – the maximum lawful 

vehicle speed for a particular location as 

displayed on a regulatory sign. Posted 

speeds are displayed in speed values 

that are multiples of 5 mph.

Statutory Speed – numerical speed 

limits (e.g. 25 mph, 55 mph), established 

by state law that apply to various 

classes or categories of roads (e.g. rural 

expressways, residential streets, gravel 

roads, primary arterials, etc.) in the 

absence of posted speed limits.
Speed Management Guidebook | 3

that provide information on implementing a successful Speed Management 

Program.4

1.3 Speed Management Program

A Speed Management Program is a strategy that addresses the concern of 

unlawful and undesirable speeds at a specific location, along a corridor, or 

within a jurisdiction’s road network. The program should be comprehensive, 

addressing all factors that influence speeding: public awareness, user behavior, 

roadway design, surrounding land uses, traffic conditions, posted speed limits, 

and enforcement. Therefore, the program should encompass engineering, 

enforcement, education, and emergency services—known as the four E’s of 

safety—when appropriate.

• Engineering is used to accomplish the following:

ͧ Establish speed limits that are appropriate to the primary purpose of the 

road, provide a balance between mobility and safety for all roadway users, 

and meet all state or local legal requirements.

ͧ Design roads that produce desired speeds.

ͧ Introduce physical countermeasures to create a self-regulating roadway 

that induces drivers to travel at the desired speed.

• Enforcement encompasses the actions taken by appropriate empowered 

authorities to check that drivers of motor vehicles are complying with the legal 

posted speed limit. Various countermeasures are used by law enforcement to 

deter motorists from speeding.

• Education entails providing information to drivers about their travel speeds 

and safety issues associated with speeding and to heighten their awareness of 

enforcement countermeasures that are designed to curtail speeding.

• Emergency Services, also known as emergency medical services (EMS), 

include quick response to crash locations and attention to victims to minimize 

the severity of the crash.

A Speed Management Program will generally follow the four-step process 

illustrated in Figure 1.

4 FHWA Office of Safety Web site: http://safety.fhwa.dot.gov
4 | Speed Management Guidebook 

Figure 1. Speed Management Program Process.

• Step 1—Identify speeding issues. A review 

of crash data, coupled with site reviews 

and public input, is needed to determine 

if there is a speeding issue and, if so, 

to what extent and from what causes. 

Partner agencies will play an integral 

role in addressing speeding and should 

be identified for coordination in moving 

forward with a Speed Management 

Program. Specific goals should be set once 

the issue has been identified.

• Step 2—Select countermeasures. Identify 

engineering, enforcement, and education 

countermeasures that may address 

the problem.

• Step 3—Implement countermeasures. The 

identified countermeasures will need to be 

prioritized, funded, and implemented in a 

systematic way.

• Step 4—Evaluate progress. Individual countermeasures or projects should be 

evaluated to determine the progress being made towards achieving the goals 

that were established for the entire Speed Management Program.

Steps 1 through 4 are continuously pursued with appropriate adjustments made 

based on the progress. This four-step process is described in more detail in the 

subsequent sections of the guide.

Benefits of a Speed 

Management Program

• Reduced fatalities and 

serious injuries from 

speeding-related crashes.

• Greater potential for 

motorists to avoid a crash.

• Enhanced safety for 

pedestrians, cyclists, 

and other vulnerable 

road users.

• Driving population 

educated on the risks and 

consequences of speeding.

• Enhanced communitywide safety culture, where 

safety is a top priority.
Speed Management Guidebook | 5

1.4 Agency Partnerships

Collaboration and coordination between agencies are essential in addressing 

speeding and speed-related crashes at any level of government and even more 

so at the local community level. With limited resources, pooling resources 

will benefit the Speed Management Program in addressing the speed-related 

crashes. Among the agencies to engage at this stage of the process in order 

to develop partnerships are law enforcement and/or public safety, local and 

county engineering department, public works department, and State DOT. The 

level of involvement in the process will depend on the nature of the speeding 

issue(s) identified. In many instances it may be beneficial to convene a Speed 

Management working group. Bringing the right agencies or individuals together 

to be part of a working group will help foster a long-term commitment and build 

momentum to implement the plan. A successful Speed Management Program 

will typically have different roles shared by different agencies.

Local rural practitioners may also decide to notify relevant elected officials 

of the speeding issues and the steps being taken to address them. Elected 

officials can encourage partner agencies to participate in the process, assist 

with policy requirements, and obtain funds for the implementation of identified 

countermeasures. For example, if a village in a rural area identifies a speeding 

issue on a county road within the village, it should consider partnering with 

the county highway department and the local police or sheriff’s department to 

address the issue.

Speed Management Guidebook | 7

2 Identify Speeding Issues 

The greater tendency to speed in rural areas may be due to the typically lower 

traffic volumes there. In some locations, the geometry of the roadway may selfregulate motor vehicle speeds. On the other hand, the geometric and roadside 

characteristics of a roadway may encourage higher speeds, such as on flat, open 

areas. Because speed enforcement activities may be sporadic in rural areas, 

speeding may go undetected or underreported until a severe crash occurs, at 

which time an immediate reaction may be to reduce the posted speed limit. 

Studies have shown that lowering the speed limit without justification does not 

effectively lead to reduced vehicle speeds. Therefore, a systematic process must 

be employed in addressing speeding.

The first step in such a process is to identify if there is a speeding issue and, if so, 

determine its magnitude and contributing factors. This entails data collection, 

an assessment of the posted speed limit, and a determination of whether 

speeds are excessive. It also involves the review of available crash and roadway 

data to isolate the factors contributing to the problem. If there is a documented 

speeding issue, then countermeasures are selected and coordinated with 

partner agencies and other stakeholders.

2.1 Data Sources

Road owners can become aware of locations with speeding issues through a 

number of sources:

• Crash records.

• Road conditions.

• Citation history.

• Partner agencies.

• Citizen concerns.

An analysis of crash records provides a solid foundation for identifying speeding 

problems. In some States, there is a specific data element on the crash report for 

the police to code the crash as speed-related. As a result, speed-related crashes 

in those States can be more-readily identified from the crash data. Typically, at 

least three years of crash data are necessary to be able to identify trends.

Some local agencies may maintain a crash records database. The agency that 

collects and maintains crash data varies by State and may include the State’s DOT, 
8 | Speed Management Guidebook 

Department of Motor Vehicles, State Police or Highway Patrol, or Department 

of Public Safety. The appropriate agency can assist a local agency with obtaining 

crash data. A local practitioner can also contact the local law enforcement agency 

or the LTAP/TTAP representative to determine the availability of crash data. The 

Strategic Highway Safety Plans (SHSPs) in some States may include speeding 

as an emphasis area, so an SHSP may provide background information on the 

source of the data or identify opportunities to coordinate with other agencies.

The crash analysis can range from creating a simple “push pin” map (on which 

clusters of crashes attributed to speeding are located) to conducting a more 

detailed review of crash reports that can be used to identify other speedrelated crash issues (e.g., crash type, time of day, weather conditions, and crash 

severity). For example, a high incidence of run-off-road crashes may be an 

indicator of speeding as a contributing factor.

In addition, exposure should be considered when analyzing crash data. 

Considering exposure allows for the more appropriate comparison of roadway 

segments or intersections. Two common types of exposure elements include 

crashes by roadway miles and crashes by traffic volume. More information on 

analyzing crash data is provided in Roadway Safety Information Analysis: A 

Manual for Local Rural Road Owners.

There may be evidence on the roadway that indicates there is a speeding 

problem. This evidence will not establish whether drivers were exceeding 

the speed limit or driving too fast for conditions but may provide information 

on locations where speed is a concern. This can be verified through agency 

staff actively observing conditions along the roadways that they routinely 

travel. Physical conditions that may indicate a speeding problem include the 

following examples:

• Skid marks are the result of rapid braking. One set of skid marks is not likely 

to indicate a chronic problem. However, multiple sets of skid marks could 

indicate a condition where motorists are choosing an inappropriate speed and 

are braking suddenly to correct their speed.

• Rutting on the outside of curves can indicate that motorists are choosing 

speeds too fast for the curve design. The ruts indicate a loss of control through 

the curve.

• Worn centerline markings on the inside of curves can indicate that motorists 

are choosing speeds too fast for the curve design.
Speed Management Guidebook | 9

• Sign knockdowns or guardrail/fencing strikes may indicate speeds too fast 

for roadway conditions. Evidence of sign knockdowns or guardrail strikes may 

be coupled with rutting.

Citations for speeding are another source of information about a speeding 

problem. Law enforcement often collects and maintains citation data that 

can be used to identify patterns in speeding. Linking these data to crash data 

provides a good understanding of the extent of the problem.

Concerns raised by a citizen or elected official are often based on personal 

observations and perceptions and should, therefore, be verified with field 

evidence. A concern expressed by an employee of a governing agency or 

law enforcement group is often based on evidence that can be found in the 

field or in the citation records. Regardless, the Speed Management Program 

should have a procedure for processing information brought forth by citizens 

and partner agencies. This information should be verified with crash data and 

citation records.

2.2 Assessing Speeding

Once an area of concern has been identified, and it has been determined that 

speeding is occurring, the next step is to determine any site-specific factors in 

speeding. As a starting point, the agency should address the following questions:

• Has the posted speed limit been set in accordance with accepted procedures 

for the location?

• Do the accepted procedures consider the types if users, such as vulnerable 

users like pedestrian and cyclists, and slower vehicles, such as farm equipment? 

Are other environmental characteristics considered?

• Are unexpected conditions being encountered, such as a transition into a 

developed area or a change in the geometry of the roadway?

• Are motorists provided with sufficient information regarding an unexpected 

condition (e.g., a gateway treatment or signage noting a change)?

• Are there any engineering deficiencies in the roadway or roadside, such as 

inadequate pavement markings or signing, that may be contributing to the 

observed speeding? For example, in a rural village, speeds may be higher 

than expected if the travel lanes and parking spaces are not properly marked, 

creating extremely wide lanes.

Although, a thorough review of police crash reports for an area of concern can 

provide insights, an agency should conduct a field review of the identified sites 

under free flow traffic conditions, which are usually observed outside of peak 
10 | Speed Management Guidebook 

periods. Free flow traffic conditions are essential when studying a location to 

capture the natural tendencies of motorists unencumbered by traffic. Peak traffic 

conditions typically occur during the morning commute to work, lunchtime, 

the evening commute from work, and some special occasions (such as certain 

holidays). Field reviews can be either informal (e.g., using only an agency’s own 

personnel) or formal (e.g., a road safety audit using an independent multidisciplinary team).5

Understanding the factors in speeding will help identify effective speed 

management strategies.

2.2.1 Assessing the Speed Limit 

Speed limits are only meaningful if the majority of motorists comply voluntarily, 

and that occurs only if a speed limit is reasonable for the conditions and meets 

drivers’ expectations. There are two methods for establishing speed limits: 

the first involves applying the statutory speed limit, while the second involves 

establishing a speed limit through an engineering study.

Statutory speed limits are established by the authority of law in each State. Some 

State laws provide speed limits for all roads on the basis of functional class (i.e., 

arterial, collector, or local road) but are not limited to these speed limits if there 

is an overriding concern. 6 In many cases, these speed limits typically apply in the 

absence of a posted speed limit and usually do not preclude the establishment 

of a speed limit based on an engineering analysis of site-specific conditions.

On the other hand, some States may provide reduced prima facie speeds under 

certain conditions. For example, speed reductions may be warranted based 

on access point/driveway density (i.e., an indication of how many driveways 

are located in a specific section of roadway). Local rural practitioners should 

understand the laws that govern speed limits in their State. If the speed limit is 

not mandated by State law, then an evaluation of a speeding concern provides an 

excellent opportunity to review the appropriateness of the posted speed limit.

Research has shown that setting speed limits based on driver behavior and the 

adjoining land use can reduce the number of speeding citations, speed variance, 

5 FHWA Road Safety Audit Web site: http://safety.fhwa.dot.gov/rsa

6 Strategies for Distributing “Speed Shatters Life” Campaign Public Service Advertising 

Materials (2011). http://www.nhtsa.gov/DOT/NHTSA/Traffic%20Injury%20Control/

Articles/Associated%20Files/strateg.pdf
Speed Management Guidebook | 11

and, most importantly, speeding-related crashes.7 The establishment of a speed 

limit based on an engineering study allows for consideration of local conditions, 

such as geometry and crash history. FHWA provides an easy to use tool—

USLIMITS, a Web-based expert advisor—for determining speed limits.8 The 

following information is needed to conduct a typical speed limit determination 

using USLIMITS:

• Land use type (e.g., high density, low density, hamlet, or rural).

• Frequency of roadside access (e.g., number of residential and commercial 

driveways, intersecting roads, etc.).

• Road function (e.g., traffic movement versus access to abutting properties).

• Facility characteristics (e.g., paved width, divided or undivided, lane width and 

number of lanes, sight restrictions, etc.).

• Current vehicle speed data (e.g., data from a speed study).

• Existing speed limits.

• Special conditions that may exist (e.g., adverse alignment, the presence of 

pedestrians and cyclists, roadside design, high crash rates, etc.).

Other information on establishing speed limits can be found in Methods and 

Practices for Setting Speed Limits: An Informational Report.

9

2.2.2 Determining if Speeds are Excessive

A speed study should be conducted in order to assess whether vehicle speeds 

are in excess of the posted speed limit and/or compatible with conditions. 

Appendix A (How to Conduct a Speed Study) provides guidance for conducting a 

speed study. Speed limits are often set by the 85th percentile speed, which is the 

point in the speed distribution at which 85 percent of vehicles travel at or below.

Use of the 85th percentile speed concept is based on the theory that the vast 

majority of drivers can be characterized by the following:

• They are reasonable and prudent.

• They do not want to be involved in a crash.

• They desire to reach their destination in the shortest possible time.

7 NCHRP Report 622 Effectiveness of Behavioral Highway Safety Countermeasures 

(2008) http://onlinepubs.trb.org/onlinepubs/nchrp/nchrp_rpt_622.pdf

8 USLIMITS Web site: http://safety.fhwa.dot.gov/uslimits

9 Forbes, G, et al., Methods and Practices for Setting Speed Limits: An Informational 

Report (2012), http://safety.fhwa.dot.gov/speedmgt/ref_mats/
12 | Speed Management Guidebook 

A speed at or below which 85 percent of people drive at any given location under 

good weather and visibility conditions may be considered as the maximum safe 

speed for that location.

The results of numerous and extensive “before-and-after” studies substantiates 

the general value of the 85th percentile criterion. Experience has also proved 

these findings valid and shows that the 85th percentile speed is the one 

characteristic of traffic speeds that most closely conforms to a speed limit that 

is considered safe and reasonable.

The data collected during the speed study is typically plotted on a graph as 

depicted in Figure 2. The graph plots the cumulative percentage for increases 

in speed. From this plot, the 85th percentile can be determined, which in this 

example is 33.2 mph. The curved line depicts the actual speed measurements on 

the road in question and the horizontal line depicts the 85th percentile speed. 

More information on how to conduct a speed study is provided in Appendix A or 

can be found in the Handbook of Simplified Practice for Traffic Studies.

10

Figure 2. Graphical Depiction of 85th Percentile Speed.

10 Center for Transportation Research and Education (CTRE). Iowa State University. 

Handbook of Simplified Practice for Traffic Studies. Iowa DOT project TR-455. 

CTRE project 01-08. November 2002. Available: www.ctre.iastate.edu/pubs/

traffichandbook/index.htm.

0

20

40

60

80

85

5 10 15 20 25 30 35 40

100

Speed (���)

85th Percentile 

is 33.2 ���
Speed Management Guidebook | 13

2.2.3 Unpaved Roads

There are over 1.4 million miles of 

unpaved roads in the United States. 

In many rural areas of the country, 

local road agencies do not have any 

paved roads under their jurisdiction. 

Unpaved roads (e.g., limestone, 

natural aggregate, dirt, and sand) 

require special consideration when 

determining appropriate speed limits.

Although usually low-volume 

facilities, unpaved roads typically lack 

adequate delineation, runoff areas, 

clear zones, and guardrails, making 

them more prone to injury and fatality-producing crashes. Hence, this type of 

road may require special consideration if a speed issue is identified.

A 2007 study conducted in Kansas supports the notion that gravel roads are 

fairly self-regulating with regard to speeds because of physical conditions, such 

as geometry, road width, and surface. 11 Speeding issues on gravel roads will be 

best addressed through the use of a combination of engineering, enforcement, 

and education countermeasures.

11 Liu, Dissanayake, Speed Limit-Related Issues on Gravel Roads (2007)

http://www.intrans.iastate.edu/pubs/midcon2007/LiuLimit.pdf

Unpaved roads frequently do not have posted 

speed limits.

Speed Management Guidebook | 15

3 Identifying Countermeasures

A coordinated approach to managing speeding and reducing speed-related 

crashes based on engineering, enforcement, and education countermeasures 

is desirable. When identifying countermeasures, practitioners should consider 

strategies that will minimize the severity of speed-related crashes. This will 

depend on location characteristics and the contributing factors of crashes 

identified from crash data and field reviews. One method to evaluate potential 

engineering countermeasures, and their ability to reduce crashes, is using 

Crash Modification Factors (CMF’s). A CMF is a multiplicative factor used to 

determine the expected change in the number of crashes after implementing a 

specific countermeasure at a specific site.12 This section provides information on 

engineering, enforcement, and education countermeasures that can be used to 

address a speeding issue.

3.1 Engineering 

Reducing the speed limit alone generally does not result in lower speeds. Several 

engineering countermeasures have been identified that can be used to influence 

driver speed choice, and the following sub-sections describe engineering 

countermeasures that address speeding. They have been grouped into three 

categories: traffic control devices, road and street design, and traffic calming on 

lower-speed roadways. Since design details are not presented, the road owner 

should seek engineering expertise when selecting countermeasures.

3.1.1 Traffic Control Devices to Reduce Speed

Installing or upgrading signs and pavement 

markings on an affected roadway can be a costeffective measure to reduce speeding. Such 

improvements include advisory speed signs and 

pavement markings, speed activated signs, and 

optical speed bars.

Advisory speeds are installed with curve warning 

signs (either on the same sign or as a supplemental 

plaque) to recommend a safe speed for traversing 

a horizontal curve. The warrant for when they 

12 Unless otherwise noted, CMFs in this document were obtained from the CMF 

Clearinghouse and are assumed to apply to all crash types. Available at: http://www.

cmfclearinghouse.org/index.cfm

Advisory speed displayed with 

curve warning sign.
16 | Speed Management Guidebook 

should be used are prescribed in the Manual on Uniform Traffic Control Devices

(MUTCD) (see Section 2C.07)13 and the procedure for setting advisory speeds on 

curves can be found in Procedures for Setting Advisory Speed Limits on Curves.

14

Advisory speed signs have been found to reduce speeds by two to three mph15

(CMF = 0.71-0.87).16

A pavement speed limit marking displays the 

posted speed limit on the pavement. It is used to 

emphasize the speed limit. A SLOW curve ahead 

pavement marking warns the driver of a potentially 

hazardous curve. This pavement marking is meant 

to supplement advsiory signs. Because they are 

exposed to traffic wear, both types of pavement 

markings require regular maintenance to ensure 

their continued visibility.

A speed activated sign is an electronic sign that is 

connected to a device that measures the speed of 

approaching vehicles. If the vehicle is exceeding 

the legal speed limit, then the electronic sign 

is activated to display the legal speed limit. This 

may also be accompanied by the word “SLOW” 

or other appropriate message. A similar device 

is a speed feedback sign. When connected to a 

speed-measuring device, a speed feedback sign displays the speed at which a 

vehicle is traveling. The speed-activated sign and the speed feedback sign can 

be effective in speed transition areas (e.g., entering a school zone or other area 

characterized by high volumes of non-motorized traffic). If used too frequently, 

the effectiveness of these signs is diminished. Speed feedback signs were found 

to reduce speeds between two and 10 mph17 (CMF = 0.54).16

13 MUTCD 2009 http://mutcd.fhwa.dot.gov/pdfs/2009/pdf_index.htm

14 Milstead, R., et al., Procedures for Setting Advisory Speed Limits on Curves (2011), 

http://safety.fhwa.dot.gov/speedmgt/ref_mats/fhwasa1122/

15 Vest, A., et al., Effect of Warning Signs on Curve Operating Speeds. Kentucky 

Transportation Center (2005), http://www.ktc.uky.edu/Reports/KTC_05_20_

SPR_259_03_1F.pdf

16 Elvik, R. and Vaa, T., “Handbook of Road Safety Measures.” Oxford, United Kingdom, 

Elsevier, (2004).

17 Hallmark, S., et al., Evaluation of Gateway and Low Cost Traffic-Calming Treatments 

for Major Routes in Small, Rural Communities (2007), http://www.intrans.iastate.edu/

reports/traffic-calming-rural.pdf

Special pavement marking to 

encourage speed reduction for 

impending curve.

A solar-powered speed 

feedback sign.
Speed Management Guidebook | 17

Optical speed bars are used at spot locations or 

along a corridor to reduce speeding. These are 

transverse pavement markings across the travel 

lane or along its edges placed with decreasing 

spacing in the direction of travel, which makes 

it appear to drivers that they are traveling faster 

than their true speed. They are placed in advance 

of a speed transition zone or other critical location. 

This treatment should be used sparingly, else it will 

lose its novelty effect, and should be maintained 

to ensure its usefulness. Optical speed bars have 

been found to reduce speeds by an average of two 

mph. More details can be found in Section 3B.22 

of the MUTCD.

3.1.2 Road and Street Designs 

There are several modifications to the design of a road or street that can induce 

speed reductions and have other safety and operational benefits for all road 

users. These include reduced lane widths, road diet, center island or median, 

and roundabout. Several of these countermeasures can be implemented on 

higher-speed roadways.

Reducing lane width to as narrow as 10 feet 

can reduce speeds. This can be accomplished 

by restriping narrower lanes without reducing 

pavement width. The remaining space can then 

be used for non-motorized uses, buffer areas 

between travel lanes and non-motorized uses,or 

space for on-street parking. In rural areas, 

reducing lane width on roadway segments should 

only be considered on lower-speed roadways 

in towns or villages. A nationwide study found 

no increase in crashes or injuries when lanes were narrowed on urban and 

suburban roadways.18 Speeds may also decrease by one to three mph for each 

foot that the roadway is narrowed down to 10 feet.19 At two way stop controlled, 

18 Potts, I., et al., Relationship of Lane Width to Safety for Urban and Suburban 

Roadways, (2007),

19 http://safety.fhwa.dot.gov/geometric/pubs/mitigationstrategies/chapter3/3_

lanewidth.htm

The lane width for motor vehicle 

travel in this community was 

reduced to provide exclusive 

space for cyclists.

Optical speed bars on a rural 

roadway placed in advance of a 

horizontal curve.
18 | Speed Management Guidebook 

rural intersections on high-speed two-lane, two-way roadways lane narrowing 

through the application of rumble strips on outside shoulders and in a painted 

yellow median island on major road approaches has been found to significantly 

reduce speeds and resulted in improved safety performance20 (CMF= 0.69).21

A road diet is a conversion of an existing street cross section to create space for 

other uses (e.g., bicycle lanes, sidewalks, turn lanes, or on-street parking). Figure 

3 is a before-and-after drawing of a typical road diet. The original road was four 

lanes with two lanes in each direction.

Figure 3. Road Diet Comparison.22

The same road width remains after the road diet, but the number of travel lanes 

for motor vehicles is reduced providing space for bicycle lanes in each direction. 

Road diets have the potential to reduce speeds due to the percieved narrowing 

of the roadway, with the extra pavement used for center turn lanes, parking, 

bicycle lanes, or other uses. Road diets have also been found to reduce crashes 

20 Bared, J., Hughes, W., Jagannathan, R., and Gross, F. “Two Low Cost Safety Concepts. 

for Two Way Stop Controlled, Rural Intersections on High Speed Two Lane, Two 

Way Roadways.” Report No. FHWA-HRT-08-063, Federal Highway Administration, 

Washington, DC. (2008)

21 Hauer, E., “Lane Width and Safety.” (2000)

22 Huang, H., et al., Summary Report: Evaluation of Lane Reduction “Road Diet” 

Measures and their Effects on Crashes and Injuries (2004), http://www.fhwa.dot.gov/

publications/research/safety/humanfac/04082/index.cfm
Speed Management Guidebook | 19

(CMF = 0.47-0.71).23, 24 More detailed information can be found in the Road Diet 

Handbook: Setting Trends for Livable Streets.

25

A center island or raised median can 

be used to create a shift in the travel 

path. Shifting traffic is an effective 

way to reduce speeds. A center 

island or raised median may also be 

used to narrow the “optical width” 

of the roadway, which will make the 

roadway appear narrower, thereby 

reducing speeds. Medians have been 

shown to be effective in lowering operating speeds, especially when they create a 

deflection in the vehicle path at the beginning of the median. However, attention 

must be given to the design of the deflection to achieve a speed reduction 

without compromising safety. For this reason center islands and raised medians 

are typically applied to developed areas- that is in towns or villages- within the 

rural context. Another positive aspect of installing medians is that pedestrians’ 

safety is improved by providing a refuge when crossing the street. According 

to trafficcalming.org installing medians as a measure for narrowing, results in 

an average speed reduction of 7 percent of the 85th percentile travel speed26

(CMF 0.29).27

A roundabout is an intersection with a raised island in the middle that vehicles must 

travel around in a counterclockwise direction. In order to enter the roundabout, 

a driver must yield to vehicles traveling in the circulatory roadway. Roundabouts 

have become popular for intersection traffic control due to documented safety 

23 Harkey, D.L., R. Srinivasan, J. Baek, B. Persaud, C. Lyon, F.M. Council, K. Eccles, N. Lefler, 

F. Gross, E. Hauer, J. Bonneson, “Crash Reduction Factors for Traffic Engineering and 

ITS Improvements”, NCHRP Project 17-25 Final Report, Washington, D.C., National 

Cooperative Highway Research Program, Transportation Research Board, (2008)

24 Persaud, B. N., Retting, R. A., Garder, P. E., and Lord, D., “Observational Before-After 

Study of the Safety Effect of U.S. Roundabout Conversions Using the Empirical Bayes 

Method.” Transportation Research Record, No. 1751, Washington, D.C., Transportation 

Research Board, National Research Council, (2001)

25 Gates, T., et al., The Safety and Operational Effects of Road Diet Conversions in 

Minnesota, 2007 TRB 86th Annual Meeting: Compendium of Papers CD-ROM, Vol. 

TRB#07-1918, Washington, DC, (2007),

26 http://trafficcalming.org/measures/center-island-narrowings/

27 Schultz, G.G., K.T. Braley, and T. Boschert, “Correlating Access Management to Crash 

Rate, Severity, and Collision Type.” TRB 87th Annual Meeting Compendium of Papers 

CD-ROM. Washington, D.C., (2008).

A center island raised median.
20 | Speed Management Guidebook 

(CMF 0.213-0.58)28, 29 and operational benefits. 

Roundabouts can be extremely effective at 

improving safety by managing speeds. According 

to the FHWA’s Proven Safety Countermeasures 

website, converting a two-way stop controlled 

intersection to a roundabout can reduce severe 

crashes by 82 percent and overall crashes by 

44 percent. Similarly, converting a signalized 

intersection to roundabout conversion can reduce 

severe crashes by 78 percent and overall crashes by 48 percent. For more 

information concerning roundabouts, refer to FHWA’s Web site on roundabouts 

at: http://safety.fhwa.dot.gov/provencountermeasures/fhwa_sa_12_005.htm.

3.1.3 Traffic Calming 

Traffic calming is the design or retrofit of a roadway to encourage uniform 

vehicle speeds and improve conditions for non-motorized users. Traffic calming 

tends to be applied to roads with operating speeds of 30 mph or less, as these 

roads are typically developed zones along rural roadways. There are numerous 

traffic calming countermeasures that can be applied on different types of roads 

and streets, and these are identified in ITE’s Traffic Calming: State of the Practice30

and the FHWA’s Engineering Countermeasures to Reduce Speeds.

31 Some of the 

measures that can be applied in rural villages are described in this section.

A speed hump is a raised section of 

asphalt approximately 10 to 14 feet 

long and 3 to 4 inches high. Speed 

humps are typically used on lowerspeed residential streets in rural 

areas that are experiencing a high 

incidence of speeding and/or cutthrough traffic.32 Speed humps are 

28 Fortuijn, L. “Turbo Roundabouts: Design Principles and Safety Performance.” TRB 88th 

Annual Meeting Compendium of Papers CD-ROM. Washington, D.C., 2009.

29 Schoon, C. and van Minnen, J., “The Safety of Roundabouts in The Netherlands.” Traffic 

Engineering & Control, Vol. 35, No. 3, London, United Kingdom, Hemming Information 

Services, (1994) pp. 142-148.

30 ITE Web site: http://www.ite.org/traffic/tcdevices.asp

31 FHWA Web site: http://safety.fhwa.dot.gov/speedmgt/ref_mats/eng_count/

32 Traffic Calming: Speed Control. Available: http://trafficcalming.org/.

A speed hump delineated to notify motor 

vehicles of its presence.

A rural roundabout.
Speed Management Guidebook | 21

not to be confused with speed bumps, which are much shorter and usually 

found in parking lots. Speed humps have been found to reduce injury crashes by 

40 to 50 percent and speeds by nine mph33 (CMF = 0.5-0.6).

Speed tables are similar to speed humps but have an 

extended flat section that can accommodate an 

entire car. This design allows for speeds of 25 to 30 

mph, which are typical for local and collector streets. 

Speed tables are generally placed on roadways 

where there is minimal heavy truck and farm vehicle 

traffic.34 Information on the design of speed humps 

and speed tables are available in ITE’s Guidelines for 

the Design and Application of Speed Humps and 

Speed Tables (see www.ite.org). According to trafficcalming.org, speed tables 

have been found to reduce speed by an average of 7.5 mph.35

A mini-roundabout is smaller than a conventional 

roundabout and has a mountable center island that is 

either flush with the pavement or slightly mounded. 

It is typically installed on roadways with speed limits 

of 35 mph or lower. This measure can reduce speeds 

by an average of 10 mph, since traffic is required to 

yield to road users in the mini-roundabout.35

A traffic circle is intended for lowvolume and low-speed roads, such 

as those in residential areas. A raised 

center island is constructed in the 

intersection. Landscaping can be 

added to the island for aesthetic value 

but should not obstruct the view 

of the intersection. A traffic circle is 

quite different from a roundabout or 

33 Elvik, R. and Vaa, T., “Handbook of Road Safety Measures.” Oxford, United Kingdom, 

Elsevier, (2004),

http://www.ite.org/safety/issuebriefs/Intersection%20Issue%20Brief.pdf

34 Evaluation of Gateway and Low Cost Traffic-Calming Treatments for Major Routes in 

Small, Rural Communities 2007, 

http://www.intrans.iastate.edu/reports/traffic-calming-rural.pdf

35 Traffic Calming: Speed Control. Available: http://trafficcalming.org/.

A speed table at a pedestrian 

crossing on a rural road.

A mini roundabout.

A traffic circle.
22 | Speed Management Guidebook 

mini-roundabout, as a yield sign is not mandatory for this intersection. Also, 

it is permissible to turn left in front of the center island, a maneuver that is 

prohibited at a conventional roundabout. Traffic circles have been found to 

reduce speeds by up to 15 mph.36

For more information on traffic circles and mini-roundabouts, FHWA has 

published an informative technical summary on mini-roundabouts that can 

be found in FHWA’s Technical Summary: Mini-Roundabouts or NCHRP 672, 

Roundabouts: An Informational Guide.

37

3.1.4 Gateway Treatments

A common speeding-related problem occurs when 

a driver approaches a rural town or village from 

a higher-speed rural road. Gateway treatments 

(also called gateways) can be used in rural areas to 

capture the attention of drivers and inform them 

that the nature of the roadway is changing, and, as a 

result, they should reduce their speed.36 A gateway 

is a “combination of traditional and nontraditional 

traffic control treatments, such as enhanced 

signing, lane reduction, colored pavements, pavement markings, experimental 

striping, gateway structures, and traditional traffic calming techniques or other 

identifiable features.”38 A key consideration is the proper use of transitional 

speed limits and the Reduced Speed Limit Ahead warning signs as prescribed in 

the MUTCD (see section 2C.38).

The gateway needs to be conspicuous to be effective. It is also important to 

ensure that devices used as part of a gateway treatment (1) are crashworthy if 

placed within the clear zone and (2) do not obstruct sight distance, as gateways 

placed in the roadway may become fixed object hazards. Gateways have been 

found to reduce speeds by an average of five mph.

36 Traffic Calming: Speed Control. Available: http://trafficcalming.org/.

37 Technical Summary: Mini-Roundabouts (February 2010) http://safety.fhwa.dot.gov/

intersection/roundabouts/fhwasa10007/fhwasa10007.pdf

38 Evaluation of Gateway and Low-Cost Traffic-Calming Treatments for Major Routes in 

Small, Rural Communities (2007), http://www.ctre.iastate.edu/reports/traffic-calmingrural.pdf

A gateway treatment entering a 

rural community. 
Speed Management Guidebook | 23

Additional information on the effectiveness of engineering countermeasures is 

available in the FHWA publication Engineering Countermeasures for Reducing 

Speeds.

39

3.2 Enforcement 

Enforcement is critical in some locations to achieve compliance with posted 

speed limits. According to the Uniform Guidelines for State Highway Safety 

Programs, more than half of all traffic stops result from speeding violations, and 

public support for speed enforcement activities depends on the confidence of 

the public that the speed enforcement is fair, rational, and motivated by safety 

concerns.40

Speed enforcement that is perceived predominantly as a means to generate 

revenue will be met with indifference, at a minimum, and active resistance, at 

worst, from the motoring public. Speed enforcement countermeasures should 

primarily be at times and locations that can be directly tied to speeding-related 

crashes and areas of excessive speeding.

Traffic enforcement seeks to generate deterrent effects on speeding that are both 

specific and general. The specific deterrence is based on the idea that individual 

drivers who are caught and punished for speeding will be dissuaded from 

committing further speeding violations in the future. The general deterrence is 

based on the assumption that the process of apprehending individual violators 

can influence the behavior of a larger segment of the driving population.

There is an established linkage between speed education efforts and speed 

enforcement initiatives. Working together, these strategies amplify the impact 

of each element’s contribution to traffic safety. NHTSA’s high-visibility model 

recommends using a strategic combination of public information, education, and 

targeted speed enforcement at times and locations where excessive speeding 

and speeding-related crashes have been documented.41 These efforts are often 

conducted periodically and last from one to several weeks so that coordinated 

39 Engineering Countermeasures for Reducing Speeds: A Desktop Reference of Potential 

Effectiveness (2009), http://safety.fhwa.dot.gov/speedmgt/ref_mats/eng_count/

40 Highway Safety Program Guideline No. 19, Uniform Guidelines for State Highway 

Safety Programs, NHTSA (2006), http://www.nhtsa.gov/nhtsa/whatsup/tea21/

tea21programs/pages/SpeedManagementPDF.pdf.

41 NHTSA’S High-Visibility Model, http://www.nhtsa.gov/DOT/NHTSA/Traffic%20

Injury%20Control/Articles/Associated%20Files/HS810851.pdf
24 | Speed Management Guidebook 

speed enforcement can take place among multiple law enforcement agencies 

on a consistent basis.

In many rural areas, individual traffic officers may be responsible for patrolling 

large areas. Rural law enforcement agencies often do not have resources available 

to respond to each traffic safety issue identified within their jurisdiction.

It is important that the engineering and law enforcement disciplines form a 

partnership to address speeding. Regular meetings between engineers and law 

enforcement officers responsible for traffic enforcement should be scheduled 

to discuss speeding concerns. Traffic engineers and law enforcement agencies 

must work closely together to identify roadway locations where engineering 

countermeasures alone will not address speeding, financial resources are not 

available to implement robust engineering measures, and speed enforcement 

strategies are needed.

The relationship between the engineering and enforcement communities 

will be beneficial to the Speed Management Program through the sharing of 

knowledge. For example, the engineering community can explain the process of 

setting speed limits to the police officers charged with enforcing them, and the 

enforcement community can discuss the need for and the optimal configuration 

of emergency pull-off areas to the individuals who are responsible for designing 

the roadway environment. Other community stakeholders (e.g., from schools, 

emergency services, hospitals, etc.) may also be invited to participate on a 

regular or as-needed basis. The Mississippi Demonstration Project, detailed in 

the box on the following page, is an example of a successful partnership between 

engineers and local law enforcement personnel that was effective in educating 

the driving population.42

3.2.1 Traditional Enforcement

The primary speed enforcement tools used by law enforcement patrol officers 

include RADAR (RAdio Detection And Ranging), LIDAR (LIght Detection And 

Ranging), and vehicle pacing. With proper training, these tools constitute 

effective means to identify and cite speeding violators. Due to the ease of use, 

accuracy, and steadily decreasing costs, RADAR and LIDAR (or laser) instruments 

have become the preferred method of speed detection by law enforcement. In 

some States, grants are available from organizations such as the Govenor’s 

42 Freedman, M., et al., Field Test of the Impact of Setting and Enforcing Rational Speed 

Limits in Gulfport, Mississippi, National Highway Transportation Safety Administration, 

Washington, DC. (2007).
Speed Management Guidebook | 25

Highway Safety Office (GHSO) to purchase or upgrade RADAR and/or LIDAR 

equipment.

For speed enforcement deployments, 

rural law enforcement agencies often 

make greater use of “moving” RADAR 

equipment (RADAR that can capture 

the speed of traffic when the patrol 

vehicle is moving). The size of a 

typical rural patrol area often requires 

officers to patrol for speeders in 

moving mode to allow them to canvas 

the large geographic areas assigned 

to them over the course of a work 

shift. In general, rural and suburban 

patrol officers are also more likely 

to work individually on speed 

enforcement compared to their urban 

counterparts. Often, when a new 

Speed Management Program is being 

unveiled, rural or suburban agencies 

will combine resources. Officers from 

several agencies within the same 

jurisdictional authority (e.g., village, 

township, county, and/or State 

agencies) will agree to work together 

to address specifically-identified stretches of a roadway where speeding and 

crashes are clearly a problem. These collaborative traffic safety efforts by law 

enforcement agencies are a means to maximize the impact of scarce resources 

and heighten awareness of speeding issues experienced by the motoring public. 

NHTSA provides each State’s GHSO with Federal funds that can be used to target 

specific traffic safety issues—and speeding is being increasingly identified as 

a priority.

3.2.2 Automated Enforcement

Automated Speed Enforcement (ASE) systems are also effective methods 

to prevent speeding-related crashes. ASE combines RADAR or LIDAR with 

sophisticated digital camera systems and computer technology to detect 

speeding violations and record identifying information about the vehicle and/or 

driver. ASE is a supplement to traditional speed enforcement countermeasures.

In 2001, NHTSA, FHWA, and the 

Mississippi DOT teamed up with the 

Cities of Gulfport and Southaven to 

carry out an assessment of setting 

rational speed limits, enforcing 

those limits, and educating the 

public on speeding-related issues. 

Gulfport used the engineering 

process of setting speed limits 

to the 85th percentile, as well as 

strict enforcement and plenty of 

public education. Southaven was 

monitored, as well, although there 

were no changes in the speed limits, 

enforcement, or public education. 

Improvements were noted in 

Gulfport in drivers’ compliance 

with the newly-introduced rational 

speed limits (based on the 85th 

percentile) as compared to 

Southaven, which kept the same 

speed limits as before. 
26 | Speed Management Guidebook 

By utilizing ASE, an agency will be able to do the following:

• Conduct speed enforcement in areas where traditional traffic stops are 

dangerous or infeasible due to the roadway design.

• Continuously conduct speed enforcement on roadways identified as highcrash locations where traditional law enforcement is not practical.

• Reduce the impacts of driver distraction and congestion that often result 

during traditional traffic stops made by law enforcement, especially during 

peak travel periods.

Agencies should check for ASE laws 

or regulations within their State when 

considering the implementation of 

ASE. Communities considering ASE as 

an option should review the USDOT 

Speed Enforcement Camera Systems 

Operational Guidelines (March 2008) 

for information on implementing and 

operating an ASE program.43

3.2.3 Vehicle Pacing

Officers in some jurisdictions may also use pacing. Pacing is an enforcement 

method in which the officer observes traffic speeds from a moving vehicle and 

then pursues a violator.44 To apply this method, a police vehicle’s speed is matched 

to that of a target vehicle, and the calibrated speedometer of the patrol car is 

used to infer the other vehicle’s speed. Pacing can be an effective, convenient 

alternative method of identifying a vehicle’s speed if a more convenient speedmeasuring device is not available.

3.3 Education

Citizen concerns and behavior often drive speed management policies and 

any associated education efforts. A comprehensive Speed Management 

43 USDOT Speed Team Enforcement Camera Systems Operational Guidelines (March 

2008), 

http://www.nhtsa.gov/DOT/NHTSA/Traffic%20Injury%20Control/Articles/

Associated%20Files/810916.pdf

44 Rural Initiatives for Traffic Safety: A Guide for the Office of Sheriff and Other Law 

Enforcement Officials in Rural Communities, NHTSA and National Sheriff’s Association, 

http://www.nhtsa.gov/people/injury/enforce/ruralinit.html

The equipment within an automated speed 

enforcement van. 
Speed Management Guidebook | 27

Program attempts. to address these concerns and behaviors through a datadriven approach.

NHTSA has developed a Speed Campaign Toolkit for public information and 

education outreach that has been tested and validated in programs across the 

United States.45 This toolkit provides example marketing materials that can 

be used or distributed to fit local needs and objectives while partnering with 

other local or national communities and organizations on developing a speed 

management strategy. More information on the toolkit can be found at http://

www.trafficsafetymarketing.gov.

NHTSA advises that traffic safety education campaigns should include 

participation from stakeholders representing law enforcement, engineering, 

public health, the judiciary, and prosecutors to ensure that agencies directly 

impacted by enforcement countermeasures are “in the loop” and have input 

into the proposed effort.46 This also includes private partners, such as hospitals, 

news organizations (newspaper, radio, and/or TV), major employers, and 

local businesses.

45 Speed Campaign Toolkit, http://trafficsafetymarketing.gov/speed/toolkit/

46 Strategies for Distributing “Speed Shatters Life” Campaign Public Service Advertising 

Materials (2011) http://www.nhtsa.gov/DOT/NHTSA/Traffic%20Injury%20Control/

Articles/Associated%20Files/strateg.pdf

Speed Management Guidebook | 29

4 Implementing Countermeasures

4.1 Preparing for Implementation

After selecting the appropriate engineering, education, and enforcement 

countermeasures, the next step is to implement them. This will involve seeking 

support, prioritizing the countermeasures, identifying sources of funding, and 

implementing pilot projects.

4.1.1 Seeking Support

Seeking support for speed-related countermeasures will require engaging the 

appropriate stakeholders. Stakeholders may be anyone affected by the Speed 

Management Program, which could include appropriate agencies, community 

groups, or individuals. Enlisting stakeholder support may include holding a 

meeting and making a short presentation or providing a short written report 

to the stakeholders on the design and expected impact of the engineering 

countermeasure or on the plan for implementing enforcement and education 

campaigns to the group. When communicating with stakeholders it is essential 

that local practitioners understand their perspective and possible role in 

implementation of the program. Other methods of seeking support for a program 

may include hosting a public information meeting or establishing an electronic 

presence (e.g., Web page, Facebook page, etc.) that can be used to disseminate 

information and solicit feedback on the proposed countermeasures.

4.1.2 Prioritization of Countermeasures

With practically every agency being constrained by limited resources, 

countermeasures will need to be prioritized. Most often, the countermeasures 

proven to provide the most impact for the investment are given the highest 

priority. The following qualities of each countermeasure should be considered 

when establishing priorities:

• Ability to reduce crashes—Countermeasures with greater benefits should 

be prioritized higher. Information on the effectiveness of various engineering 

strategies can be found on the FHWA CMF Clearinghouse Web site.47

Enforcement and educational countermeasures can be found in the NHTSA 

publication, Countermeasures that Work.

48

47 www.cmfclearinghouse.com

48 NHTSA, Countermeasures that Work: A Highway Safety Countermeasures Guide for 

State Highway Safety Offices, Sixth Edition (2011).
30 | Speed Management Guidebook 

• Potential for quick implementation—Countermeasures that can be 

implemented quickly (within a year) should have a higher priority. By giving 

greater priority to countermeasures that can be implemented quickly, 

an agency can ensure that the issue does not go unaddressed for several 

years while waiting for the implementation. Signing, pavement markings, 

and traditional enforcement are examples of countermeasures that can be 

implemented quickly.

• Benefit/cost results—Countermeasures with a greater lifecycle benefit/

cost (B/C) ratio should have a higher priority, as they represent the most 

cost effective solutions. Calculating a B/C ratio requires information on the 

effectiveness and costs of the speed management strategy.

• Potential to reduce speeds—Countermeasures that are expected to result in 

significant reductions in vehicle speeds should have a higher priority.

For example, The Pennsylvania DOT (PennDOT) has a system to prioritize traffic 

calming measures in which points are assigned to locations based on criteria 

that include speed, volume, crashes, proximity to a school, and pedestrian 

facilities/generators; the greater the number of points, the greater the priority 

that is given to that location.49 Table 1 outlines the ranking system used with the 

PennDOT program.

Table 1. Example Project Ranking System.

Criteria Pts. Basis for Point Assignment

Speed 0 to 30 Extent by which 85th percentile speeds exceed 

posted speed limit; 2 pts. assigned for every 1 mph

Volume 0 to 5 Average daily traffic volumes (1 pt for every 120 

vehicles)

Crashes 0 to 10 1 pt assigned for each crash reported within the 

past three years

Elementary or 

Middle Schools 0 to 10 5 pts. for each school crossing along the project street

Pedestrian 

Generators 0 to 15

5 pts. for each public facility (such as parks, 

community centers, and schools) or commercial use 

that generates a significant number of pedestrians

Pedestrian 

Facilities 0 to 10

5 pts. if there are no continuous sidewalks on one 

side of the street; 10 pts. if sidewalk is missing on 

both sides.

Total Possible Points is 100

49 Pennsylvania Traffic Calming Handbook, PennDOT, http://www.dot.state.pa.us/

Internet/pdHwyIntHS.nsf/HomePageTrafficCalming?OpenForm&BaseTarget=main
Speed Management Guidebook | 31

4.1.3 Funding

Identifying funding for each of the proposed countermeasures is essential to 

ensuring its implementation. There are a variety of different sources that can be 

used to implement the countermeasures. For engineering countermeasures, the 

Highway Safety Improvement Program (HSIP)50 program is a good place to start, 

as it is a source of Federal funds that are typically administered by the State 

DOT. Because States use various methodologies to administer these funds, the 

practitioner should check with the State DOT on their availability.

For enforcement, education, and emergency services strategies, Section 402 

funds should be considered. Section 402 funds are typically administered by 

each State’s GHSO.51 Other State, local, and tribal funds may also be available 

for the implementation of selected countermeasures. Working with stakeholder 

agencies to develop speed management program can result in the pooling of 

resources for an effective program.

4.1.4 Planning and Using Pilot Projects

Implementing new strategies can be a challenge for an agency or community. 

It may be helpful to conduct a pilot project to introduce a new engineering 

strategy (e.g., a roundabout) or an enforcement strategy (e.g., ASE method). 

Consider starting small by selecting a pilot location, or use a similar project 

located in a nearby location to demonstrate the effectiveness of the strategy. 

Effectiveness can be assessed by collecting data (e.g., speed and/or crash data) 

both before and after the installation of the countermeasure.

4.2 Evaluate Progress

Once a selected strategy has been implemented, it is important to evaluate 

its safety effectiveness. If it has been successful in reducing crashes and 

fatalities, then the evaluation will provide justification to potentially expand 

the use of the countermeasure. This section summarizes how to evaluate a 

speed management strategy that can be used for either one individual project 

or as part of a community-wide program. Each evaluation should be tailored 

to address specific countermeasures and conditions through analyses of the 

available data.

50 http://safety.fhwa.dot.gov/hsip

51 http://www.ghsa.org/html/links/shsos.html
32 | Speed Management Guidebook 

An evaluation of the impact on crash history should not be conducted until at 

least one year of post-installation data is available, and a minimum of three 

years of crash data are desirable to provide a larger sample size. The purpose of 

an effectiveness study is to determine if there has been a significant impact on 

the frequency or severity of crashes as a result of the installed countermeasure.

The recommended timeframe for a speed evaluation after a major engineering 

change (e.g., a new speed limit or road design element) is also one year. Waiting 

a full year will allow motorists to get acclimated to the new treatment and 

environment and will allow it to be encountered in all types of weather conditions.

The evaluation timeframe will depend on the type of countermeasure strategy 

pursued and the project types. The strategy must be evaluated to determine if 

it has been effective, partially effective, or not effective.

The simplest method for evaluating speed management strategies involves 

a comparison of the speed data collected before and after implementation, 

although it can lead to misleading results. One source of information on 

vehicle speeds is a full speed study conducted specifically for the purpose of 

evaluating speed management strategies. A formal speed study will provide 

the complete speed profile for the subject roadway segment and will allow a 

direct comparison of the observed 85th percentile speeds both before and after 

implementation. Additional information on how to conduct a speed study is 

provided in the appendix.

If an agency does not have adequate resources to execute a full speed study in 

conjunction with the evaluation, it may also look to some existing databases for 

information on vehicle speeds. For instance, the number of speeding citations 

issued during the before- and after-periods may be available from the files of 

a local law enforcement group. While the number of citations issued will not 

provide a complete speed profile for the subject roadway, it may still serve as a 

basic indicator of how successful a strategy was in mitigating a noted speeding 

problem. When resources other than a full speed study are used to gather speed 

information, one should consider any potential biases that could be introduced 

by those resources. For this example of using the number of citations issued, 

the evaluation should consider whether or not the intensity of the enforcement 

activities before the strategy implementation was significantly different than 

that afterward; i.e., did the number of citations issued increase or decrease 

simply because of changes in the nature of the enforcement practices.
Speed Management Guidebook | 33

After countermeasures have been in place for at least one year, an interim 

evaluation can take place. However, at least three years of after data are required 

for a comprehensive evaluation of implemented strategies. A before-and-after 

crash study can be conducted to evaluate the effectiveness of implemented 

strategies in improving safety when sufficient data are available. Details on 

creating a well-designed and executed before-and-after crash study can be 

found in A Guide to Developing Quality Crash Modification Factors52 or in the 

Highway Safety Manual (HSM).

52 Gross, F., et al., A Guide for Developing Quality Crash Modification Factors, FHWA 

Office of Safety (2010), http://safety.fhwa.dot.gov/tools/crf/resources/fhwasa10032/

Speed Management Guidebook | 35

5 Summary

Speeding is defined as exceeding the posted speed limit or driving too fast for 

conditions. Crashes involving speeding occur on all road types but are particularly 

prevalent on the local rural road system. Of the fatal crashes occurring on local 

rural roads, nearly one-third involved speeding. As the speed increases, the 

likelihood of a crash resulting in a serious injury or fatality also increases.

Addressing this safety issue can be a challenge for local roadway agencies 

because of limited resources. Nonetheless, all agencies, regardless of size 

and resources, can develop a Speed Management Program that provides a 

comprehensive strategy to address the concern of unlawful and undesirable 

speeds. Accordingly, the program should encompass engineering, enforcement, 

education, and emergency services strategies—the four E’s of safety—to address 

speeding and speed-related crashes that result in fatalities and serious injuries. 

In general, developing a Speed Management Program involves four steps:

• Step 1. Identify speeding issues and partner agencies.

• Step 2. Select countermeasures.

• Step 3. Implement countermeasures.

• Step 4. Evaluate progress.

Successful development of a Speed Management Program begins with 

identifying the speeding issue through data. A variety of data—including crash 

(at least three years of data), citation, roadway and conditions, citation, and 

input from partner agencies—can be used to identify areas where speeding is an 

issue. Once the data have been analyzed and a location has been identified, local 

practitioners should coordinate with partner agencies such as law enforcement, 

other road agencies (if applicable), and other stakeholders to identify program 

goals and determine the specific causes of the speeding issue. This usually 

entails a field assessment and evaluation. These partnerships will not only help 

with gaining a more thorough understanding of the problem, but they will also 

be essential in supporting and implementing the Speed Management Program.

Once the causes of the speeding issue have been identified, countermeasures are 

selected that comprehensively address the issues. Engineering, enforcement, 

and education countermeasures may be selected, and a combination of 

these strategies will often bring greater impact in addressing the speeding 

issue. Engineering countermeasures can range from upgrades to the signing 

and pavement markings to modifications to the geometric configuration of 
the roadway. Other countermeasures may include targeted enforcement 

campaigns, automated speed enforcement, or public information and education 

campaigns. The measures selected will then have to be communicated to the 

various stakeholders to gain support in implementing the program.

Resources to address speeding are generally limited. Therefore, countermeasures 

that address speeding issues will need to be prioritized and funded for 

implementation in a systematic way. Prioritization can be based on those 

strategies most likely to impact the issue or on the cost relative to the safety 

benefit or implementation time.

The individual countermeasures or projects should be evaluated to determine 

the progress being made towards achieving the goals established for the 

entire Speed Management Program. The evaluation will also determine the 

effectiveness of the countermeasure within the jurisdiction to determine if it 

should be applied at other areas.

Elements of this model Speed Management Program can be followed by 

all agencies, regardless of size and resources. In developing such a program, 

assistance should be sought from such organizations as the State DOT, LTAP, 

and TTAP. By following this process, local rural road practitioners can implement 

a comprehensive program that addresses the safety issues associated with 

speeding in their communities, and this, in turn, will help to protect the lives and 

improve the safety of all road users.
Speed Management Guidebook | A-1

Appendix: How to Conduct a Speed Study

In conducting a speed study, there are three primary techniques by which 

vehicle speeds are routinely collected:

1. Traffic counter method.

2. Time-measured zone method.

3. RADAR/LIDAR method.

The recommended minimum sample size is 100 free-flow vehicles. If a study 

is being conducted on a very low-volume roadway, then it is acceptable to 

collect speeds for two hours, regardless of how many vehicles are observed. 

Environmental conditions must be considered, as well, as drivers typically do 

not travel at a normal speed while the roadway is wet or snow covered.

Another important consideration for the speed study is the time of day during 

which the data will be collected. For a low-volume roadway, the peak hours of 

the morning (typically from 7:00 to 9:00 AM) and the afternoon (typically from 

4:00 to 6:00 PM) are time periods when the study should be conducted in order 

to increase the likelihood of observing a minimum of 100 vehicles. On more 

heavily-traveled roadways, however, the morning and afternoon peak periods 

are times when speed studies should not be conducted, since the speeds 

observed while the traffic volumes are at or near capacity are unlikely to be an 

accurate reflection of free-flow speeds.

Traffic Counter Method

One of the most common types of traffic counter 

is the portable traffic count station that is used 

routinely by State DOTs and other agencies to 

procure traffic volumes at various locations 

within their jurisdiction. These traffic counters 

are characterized by two hoses that are placed a 

short distance from one another across the travel 

lane(s) of interest. Many of these devices have 

the capability to collect multiple data variables, including vehicle speeds. If an 

agency’s traffic counters are so equipped, set the control unit to collect vehicle 

speeds and deploy the apparatus as specified by the traffic counter manual. 

The data will be stored in the field unit and can later be downloaded into a 

spreadsheet and analyzed to compute various measures of speed.

Traffic Counters.
A-2 | Speed Management Guidebook 

Time-Measured Zone Method

A second method of conducting a speed study involves recording the length 

of time that it takes vehicles to traverse a known distance along the roadway. 

This process is a relatively straightforward one and begins by establishing a 

zone within the segment of interest having the length specified in Table 2. (The 

appropriate zone length is dependent upon the posted speed limit.) The zone 

should be an area in which both entering and exiting vehicles are clearly visible 

to a field observer. It will be helpful to mark the beginning and ending limits of 

the zone with some reference indicator (e.g., a sign, crack in the pavement, cone 

on the side of the road,etc.).

Table 2. Length of Measured Zone per Speed Limit.

Speed Limit (mph) Conventional Distance to Measure (ft)

Below 25 88

25-40 176

40 and Above 264

Source: http://www.ctre.iastate.edu/PUBS/traffichandbook/2SpotSpeed.pdf

A vehicle reference point should be identified to be used in determining the 

instant at which the observer will start and stop the stopwatch. This is typically 

the vehicle’s front or rear tire, and either can be selected as long as the same 

reference point is used at both the entrance to and the exit from the zone. It 

is extremely important to be consistent in using the same reference point at 

each end of the zone, as failing to do so will render the recorded times (and 

corresponding vehicle speeds) inaccurate.

While conducting the survey, the observer should stand at a safe location on 

the side of the road where a vehicle will exit the measured zone, having a clear 

view of the beginning of the zone. The observer should start the stop watch at 

the instant the reference point on the vehicle reaches the beginning limit of the 

zone and stop the timer the instant that same vehicle reference point reaches 

the end of the zone. After each vehicle travels through the zone, its time should 

be recorded by the observer. When two hours have lapsed (or, if pressed for 

time, when 100 vehicles have passed), the recorded times can be converted into 

the observed vehicle speeds. Table 3 displays the speeds corresponding to the 

times (in seconds) recorded for the vehicles to travel the measured distance (in 

feet) defined by the zone.
Speed Management Guidebook | A-3

Table 3. Speed of Vehicle Over Distance for Various Times.

Time 

(sec)

Speed by Distance (MPH) Time 

(sec)

Speed by Distance (MPH)

88 176 264 88 176 264

1 60 -- -- 3.6 16.7 33.3 50

1.2 50 -- -- 3.8 15.8 31.6 47.4

1.4 42.9 -- -- 4 15 30 45

1.6 37.5 -- -- 4.2 14.3 28.6 42.9

1.8 33.3 -- -- 4.4 13.6 27.3 40.9

2 30 60 90 4.6 13 26.1 39.1

2.2 27.3 54.5 81.8 4.8 12.5 25 37.5

2.4 25 50 75 5 12 24 36

2.6 23.1 46.2 69.2 5.2 11.5 23.1 34.6

2.8 21.4 42.9 64.3 5.4 11.1 22.2 33.3

3 20 40 60 5.6 10.7 21.4 32.1

3.2 18.8 37.5 56.3 5.8 10.3 20.7 31

3.4 17.6 35.3 52.9 6 10 20 30

Radar/Laser Method

Another method to conduct a speed study is by the use of RADAR or LIDAR. 

Observers select a safe location on the side of the roadway that is hidden from 

approaching traffic so as to not impact driver behavior and disturb the flow 

of traffic.

The observer must record the highest free flow speed of vehicles. If there is a 

large platoon of vehicles, only the first vehicle in the platoon should be measured 

for speed. The observer must also target subject vehicles so as to lessen the 

angle between the observer and the traveling vehicle. If there is a substantial 

angle between the observer and the vehicle, there speed measurement may be 

inaccurate. Any radar/laser equipment used to conduct speed studies should be 

calibrated, and users of the equipment should be properly trained.

Figure 4 provides a sample data collection sheet that may be used to conduct 

a speed study. Conditions such as weather, location, date, time, and the posted 

speed limit should be recorded on the sheet. It is important to accurately record 

this data for comparison to other studies. As a vehicle travels past the observer 

the maximum speed is marked on the data collection form. Each row starts at the 

left side of the page and each successive box is marked as speeds are observed.
A-4 | Speed Management Guidebook 

Figure 5 provides an example of a completed data collection sheet.

Figure 4. Blank Speed Survey Field Sheet.

Speed Limit: Name:

Direction: Address:

Time: Area of Roadway Studied:

Date:

Weather:

Speed Number of Vehicles

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

75

70

65

60

55

50

45

40

35

30

25

20

15

Speed Survey Field Sheet
Speed Management Guidebook | A-5

Figure 5. Sample Speed Survey Field Sheet.
A-6 | Speed Management Guidebook 

Post Data Collection

Once speeds are collected by any of the three methods it is then essential to 

determine the 85th percentile speed to compare to the posted speed limit. 

The 85th percentile speed is computed by finding the cumulative frequency 

percentage. As seen in Figure 6, common spreadsheet programs can be utilized 

to automatically perform this computation.

A technique to graphically depict the 85th percentile speed is to graph the 

speed along the x-axis and the cumulative percentage along the y-axis. A line 

can be drawn at 85 percent horizontally across until it intersects the line for the 

recorded speeds. At that point, a line can be drawn from that intersection point 

to the x-axis providing the 85th percentile speed.

Figure 6. Graphical depiction of 85th percentile speed.

When evaluating the 85th percentile speed and readjusting the posted speed 

limit of the roadway, the speed limit can only be posted in increments of five 

miles per hour (i.e., 25, 30, or 35 mph). In the example above the 85th percentile 

is 33.2 mph, since this speed cannot be chosen as the speed limit it is advised 

to round the speed limit up to the nearest 5 mph increment, which would be 

35 mph.

0

20

40

60

80

85

5 10 15 20 25 30 35 40

100

Speed (���)

85th Percentile 

is 33.2 ���
For More Information

Office of Safety

Federal Highway Administration

1200 New Jersey Ave, SE

Washington, DC 20590-9898

http://safety.fhwa.dot.gov

FHWA-SA-12-027