May 2012
Quality Assurance Statement

The Federal Highway Administration (FHWA) provides high-quality 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 quality issues and adjusts its programs and processes for continuous quality improvement.
Van Schalkwyk, I.; Wemple, E.A., and Neuman, T.R.

9. Performing Organization Name and Address

Cambridge Systematics, Inc.

100 CambridgePark Drive, Suite 400

Cambridge, MA 02140

10. Work Unit No.

11. Contract or Grant No.

DTFH61-05-D-00026-T-10-001

12. Sponsoring Agency Name and Address

U.S. Department of Transportation

Federal Highway Administration

Offi ce of Safety E71-115

1200 New Jersey Ave, SE

Washington, DC 20590

13. Type of Report and Period Cover

14. Sponsoring Agency Code

15. Supplementary Notes

FHWA: Esther Strawder, Offi ce of Safety (COTM)

16. Abstract

This guide provides examples of opportunities for integrating the AASHTO Highway Safety Manual 

into the project development process. This includes integrating methods from the Highway Safety 

Manual into planning, alternatives development and analysis, design, operations, and maintenance. 

The guide provides a description of each of these steps in the project development process, and then 

provides a discussion of the methods from the Highway Safety Manual, and in some cases other 

resources, that support these steps. The application of safety analysis tools such as the Integrated 

Highway Safety Design Model, SafetyAnalyst, the CMF Clearinghouse, and example spreadsheet too

are discussed. Resources from FHWA and NCHRP are also presented. The purpose of this guide is t

provide the practitioners with examples and ideas for integrating safety performance measures into t

project development process.

17. Key Words 

Safety, Highway Safety Manual

18. Distribution Statement

19. Security Classif. (of this report) 

Unclassifi ed

20. Security Classif. (of this page) 

Unclassifi ed

21. No of Pages 

38

22. Price

N/A

Form DOT F 1700.7 (8-72) Reproduction of completed pages authoriz
i

Applying the HSM in Operations and Maintenance ..................................................................................2

Safety Analysis Tools ...................................................................................................................................3

I. Introduction .....................................................................................................................................................4

1. How to Use the Guide ..............................................................................................................................4

2. Overview of Applying HSM in the Project Development Process ......................................................5

3. Resources for Application of the HSM ..................................................................................................7

II. Applying the HSM in Planning .....................................................................................................................9

1. Integrating Highway Safety Manual Analysis Methods into a Long Range Transportation Plan .10

2. Integrating the Highway Safety Manual into Corridor Planning .......................................................10

3. Tools to Support Application of the HSM in Planning .......................................................................11

4. Example Application: Long Range Transportation Plan ..................................................................12

III. Applying the HSM in Alternatives 

Development and Analysis .........................................................................................................................13

1. Project Scoping and “Purpose and Need” ..........................................................................................13

2. Applying the HSM in Environmental Analysis ....................................................................................14

3. Tools to Support Application of the HSM in Alternatives Development and Analysis ..................17

4. Example Application: Alternative Analysis .......................................................................................17

IV. Applying the HSM in Design ......................................................................................................................22

1. Safety Performance-Based Design ......................................................................................................22

2. Design Decisions and the HSM ............................................................................................................23

3. Example Application: Design Exception Evaluation ........................................................................24

V. Applying the HSM in Operations and Maintenance ...............................................................................25

1. Performance Measures .........................................................................................................................25

2. Operations ..............................................................................................................................................26

3. Maintenance ...........................................................................................................................................27

VI. Summary .......................................................................................................................................................28

References ...........................................................................................................................................................29

List of Acronyms .................................................................................................................................................31
ii

y yy 

 in the Example Application ....................................................................................................20

EXHIBIT 8: Safety Analysis Results for a Design Exception Evaluation ..............................................24
iii
1

Whether the project purpose is safety-related or not, every project can benefi t from applying 

HSM to the development and evaluation of alternatives. Project decisions are based on full 

evaluation of costs, right-of-way, traffi c operations, environmental factors, and safety. Prior to 

publication of the HSM, the area of safety lacked a common, science-based, and reliable mean

of quantifi cation – which is what the HSM offers.

The Integrating the HSM into the Highway Project Development Process guide provides informatio

for state and local practitioners on how to integrate the HSM into their project development p

cess. Each section provides an overview of some of the implementation opportunities for the 

HSM during each stage of the project development process. The HSM, integrated into agency 

processes and considerations, will support regional, state, and national fatality reduction goa

alongside the goals of mobility, the environment, and other competing needs.

Applying the HSM in Planning

Transportation planning legislation is increasingly emphasizing the importance of safety in 

transportation planning. When agencies are considering implementing or modifying policie

the HSM provides the ability to assess anticipated changes in crash frequency or severity, 

allowing explicit consideration of the safety impacts in addition to potential traffi c operations 

and/or economic impacts. For example, if an agency is considering an access management 

policy on all arterial roadways throughout the community, the HSM provides crash modifi ca

tion factors that quantify the change in crash frequency or severity associated with changing 

driveway density. Therefore, safety can be a performance measure along with traffi c operatio

and economic impacts. In terms of corridor-specifi c plans, the HSM can also assist with refi n

ments to the plan by allowing planners and engineers to estimate the change in safety perfor

mance across different concepts and approaches considered for a corridor. For example, the 

HSM can be used to assess the infl uence of the type and frequency of intersections, driveway

parking, or median types on crash frequency for an urban or suburban arterial.

Applying the HSM in Alternatives Development and Analysis

Within the typical project development process and during environmental analysis, agencies 

can apply the HSM to include quantitative safety in alternatives development and analysis. T

HSM provides methods for agencies to objectively defi ne locations or projects for which the 

potential for safety improvement is indeed signifi cant or not. With adoption of tools and metho

in the HSM, agencies can incorporate the historic safety performance of the existing road into 

their designation of project type and support the identifi cation of likely reasonable alternatives

Furthermore, agencies can apply the HSM to support explicit consideration of quantitative 
2

design parameter, evaluate the impact of design exceptions on safety performance, and revie

implemented projects to evaluate impacts of design criteria. The science-based human factor

fundamentals in the HSM allow the designer to assess the interactions of the road user with 

highway and evaluate design solutions based on user abilities and limitations.

The HSM does not require agencies to select a particular solution purely because it has the 

lowest associated crash frequency or severity. However, the tools in the HSM allow agencies 

review a selected alternative (that may not have had the lowest associated crashes or severity

and evaluate opportunities to reduce the associated crash frequency or severity.

Applying the HSM in Operations and Maintenance

In the day-to-day operation and management of the transportation system, agencies are resp

sible for providing a safe and effi cient transportation system for users. Within these program

projects and activities the HSM offers data driven and science-based methods and tools to 

supplement system monitoring, identifi cation of opportunities for improvement and assesses 

the safety impacts of operations and maintenance activities.

Typical applications include:

• Identifying safety performance measures across the system.

• Identifying typical locations in a geographical region that may particularly benefi t from 

systemic treatments.

• Identifying and assessing changes in safety performance for different operational and site 

conditions.

• Evaluating and quantifying the impact of treatments, policies and programs on the safety 

performance of corridors, road segments, intersections, groups of treatments, or the roadway network.

• Inform and improve maintenance policies and priorities.

• Assessing tradeoffs between funding maintenance improvements to such areas as pavements, roadside facilities, and bridge facilities.

1

 In this guide, the “predictive method” refers to the 18-step process outlined in the HSM. In summary th

steps are select and apply the appropriate safety performance function and crash modifi cation factors, 

apply a calibration factor if available, and apply the empirical Bayes method, if appropriate. 
3

Performance Committee web site at http://www.safetyperformance.org.
4

and funded its development into a practitioner-friendly document.

The HSM provides a set of tools and knowledge to support a science-based approach to quan

fying safety. As a tool, the HSM provides the ability to incorporate meaningful safety metric

crash frequency and severity – into an agency’s program planning and project development 

processes, whether the project’s purpose is driven by a particular safety concern or not.

For the fi rst time, there is standardized guidance for incorporating safety performance-based 

decision making into project development. Planners, designers, and traffi c engineers are now 

able to evaluate the impacts of decisions about the roadway environment (e.g., roadway desig

or changes in traffi c volume) on crash frequency and crash severity.

This guide provides information for state and local practitioners on how to integrate the HSM 

into their project development processes. Each section provides an overview of possible imp

mentation opportunities for the HSM during each stage of the project development process.

1. How to Use the Guide

Exhibit 1 illustrates the major steps of the project development process and provides a simpli

fi ed explanation of activities in each step. Each section in this guide provides discussion of h

the HSM could be applied in this process. Practitioners who work on each step of this proces

will fi nd specifi c chapters useful as they apply to their areas. Safety practitioners can use thi

guide to communicate these applications to their colleagues in other areas of the developmen

process. To this end:

• Section II discusses how agencies can use the HSM in planning;

• Section III discusses the use of the HSM in alternative development and analysis;

• Section IV focuses on how agencies can apply the HSM in design;

• Section V presents the application of the HSM in the operation and maintenance of the 

roadway system; and

• Section VI provides a summary of this guide.
5

(g, pp

tion or metropolitan planning organ

zations) assess existing conditions, 

establish goals and objectives, identif

future travel characteristics, and eva

ate the multimodal transportation 

network to develop programs, identi

and prioritize projects, and institute 

policies to address long-term (i.e., 20 

years) transportation system and 

community needs. During Planning, 

agencies may identify locations on th

system that have potential for safety 

improvement or sites most likely to 

respond to particular treatments.

Agencies may also be interested in 

adopting policies across the jurisdict

or understanding the quantitative 

safety implication of one network 

versus another. When agencies inclu

safety performance in planning, they 

are promoting longer-term approach

to support the reduction in the numb

and severity of crashes.

The inclusion of safety performance i

planning supports strategic investme

where the impact is likely to be the 

highest. When agencies use data driv

processes that include consideration o

safety performance, the likelihood of cost-effective expenditure of resources is increased. 

Section II discusses the application of the HSM in planning in further detail.

Individual projects are derived from agency planning efforts. Projects have defi ned limits, 

budgets, and schedules for completion, which constitute the project’s scope. Every project ha

fundamental purpose or objective, typically refl ecting needs such as providing improvement

to mobility, infrastructure repair or rehabilitation, expansion of modal choice, or improvemen

to public safety. Any of these may be expressed as a project’s “purpose and need.”

Typically includes:

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a) Projects scope/Purpose and need

b) Traffic analysis 

c) Preliminary alternatives

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 noise, traffic, socio/economic, visual effects)

f) Cost-benefit analysis

g) Refine alternatives*

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 - 60% design plans

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Construction

Note: The process outlined above is generic and for the purpose of 

discussions in this document only. The process may differ in terminology and process across project types and across agency-specifi c 

processes and procedures.

* Include mitigating impacts and the Draft EIS when an EIS 

is required.

** Include the Final EIS and Record of Decision when an EIS 

is required.
6

The HSM allows agencies to consider the existing potential 

a detailed engineering and environmental analyses of 

each alternative, results from safety diagnostic analyses 

(HSM Chapter 5) can be used to inform the development 

of concepts, and the predictive method can be used to 

estimate changes in crash frequency or severity between 

different options.

The predictive method can also be used as part of an 

alternatives evaluation process to estimate the changes in 

crash frequency or severity associated with a change in 

traffi c volume or traffi c control. Finally, the safety benefi ts 

of a preferred alternative compared with a no-build alternative can be readily estimated and incorporated into 

project documentation. Section III presents examples of opportunities for the application of t

HSM in alternatives development and analysis and selection of a preferred alternative.

Once a preferred alternative is selected, the project typically moves into Preliminary and Final 

Design. A designer can use the knowledge and tools in the HSM to inform design decisions 

throughout Final Design and Construction. For example, designers can incorporate human fact

considerations into designs (using Chapter 2 of the HSM). The need for design exceptions (use 

a design element or dimension outside of the established criteria) is common on urban projec

and reconstruction projects with extensive constraints. Analysis, decision making and documentation of the quantitative safety effects of a proposed design exception are among the mo

signifi cant enhancements the HSM brings to project development.

In the daily operation of the roadway network, agencies can use the HSM in Operations and 

Maintenance. Agencies can incorporate safety into existing processes that monitor system 

per-formance, allowing for consideration of safety performance improvements along with 

com-peting needs. This approach supports strategic investment and improvement of the roa

way system. For example, agencies can consider the impact of changes or upgrades in mobili

decisions related to access, setting maintenance policies and priorities, and other operational 

considerations on safety performance. When agencies apply the evaluation methods in the 

HSM to implemented projects and policies, they can identify opportunities to improve polici

and future decision making based on the changes in crash frequency or severity.

In reviewing this guide, agencies will fi nd the HSM provides opportunities to extend safety 

performance as a consideration into all decisions about the roadway environment (e.g., with 

maintenance, mobility, or preservation programs), rather than only considering safety in proj

ects driven by safety needs.

Safety Return on Investment

A return-on-investment evalu

ation provides information 

about whether the proposed 

action maximizes system 

benefi t. With the HSM, safety 

can be considered as a benefi t 

(alongside mobility, environment, etc.) included in the 

return on investment evaluation.
7

• The FHWA CMF Clearinghouse (cmfclearinghouse.org) supports the use of HSM Part B: 

Roadway Safety Management and Part D: Crash Modifi cation Factors.

Each HSM application example provided in this guide includes references to applicable tools

Exhibit 2 lists and briefl y describes different resources that support HSM implementation. 

Several web sites offer HSM guidance, technical assistance, case studies, and training opportunit

• AASHTO web site at http://www.highwaysafetymanual.org.

• FHWA Safety web site at http://safety.fhwa.dot.gov/hsm.

• TRB Highway Safety Performance Committee web site at http://www.safetyperformance.o
8

those initiated to improve safety performance (http://safety.fhwa.dot.gov/hsm).

• HSM Implementation Guide for Managers (FHWA) – Guidance to amanagers of state and 

local agencies for the implementation of the HSM (http://safety.fhwa.dot.gov/hsm).

• HSM User Guide (NCHRP 17-50) – Step-by-step presentaetion of application of the HSM – 

Forthcoming Spring 2012.

• HSM Training Guide (FHWA) – Lists current training available to help institutionalize the 

HSM (http://safety.fhwa.dot.gov/hsm).

• Human Factors Guidelines for Road Systems (NCHRP Report 600):

• http://www.trb.org/Main/Blurbs/159691.aspx.

• FHWA Guidance for Preparing and Processing Environmental and Section 4(F) 

Documents, FHWA Technical Advisory T6640.8A: 

http://environment.fhwa.dot.gov/projdev/impTA6640.asp.

• Integrating Road Safety into NEPA Analysis: A Primer for Safety and Environmental 

Professionals: http://safety.fhwa.dot.gov/hsip/tsp/fhwasa1136/fhwasa1136.pdf.

 Technical Support

• Highway Safety Manual web site: http://www.highwaysafetymanual.org.

• HSM User Discussion Forum offers technical assistance for the feedback from HSM users

http://www.hsmforum.org.

 Software Tools

• SafetyAnalyst AASHTOWare: http://www.safetyanalyst.org.

• Interactive Highway Safety Design Model: http://www.ihsdm.org.

• FHWA Crash Modifi cation Factors Clearinghouse: http://www.cmfclearinghouse.org.

 General Information

• HSM-related resouces: http://safety.fhwa.dot.gov/hsm.

• HSM Case Studies (FHWA) – Case studies of states applying the HSM and related software

(http://safety.fhwa.dot.gov/hsm).

• Highway Safety Manual On Line Overview Course (FHWA-NHI-380106)

(http://www.nhi.fhwa.dot.gov/training) additional HSM courses available.

• HSIP Manual: http://safety.fhwa.dot.gov/hsip/resources/fhwasa09029/fhwasa09029.pdf.

• TRB Highway Safety Performance Committee web site: http://www.safetyperformance.org –

research and support activities for the HSM and the broader context of highway safety performance.
9

freight systems, coordination of land use, intelligent transportation system improvements, 

safety needs, or parking system management.

Systems planning ranges from the initial defi nition of a community vision to the actual moni

toring of the performance of the projects that have been implemented. The primary purpose 

systems planning is to provide the information necessary and needed by decision-makers to 

make choices about investment in the transportation system consistent with a community’s 

vision.2

 System planning often starts with policy-level documents leading to modal plans an

programs. The modal plans and programs can be mode-specifi c (e.g., freight, transit, nonmotorized, and highway) and documented in one comprehensive plan or by separate plans th

focus on select topic areas. The planning process should consider the interaction among diffe

ent modes in developing a multimodal system plan. At the regional level, the mode-specifi c 

and multimodal plans often culminate in a prioritized list of projects for the 20-year horizon 

the plan. In some cases, the long range plans will also identify the need for additional refi ned 

analysis in a specifi c corridor or subarea within the community.

Quantitative performance measures in safety commonly include crash frequency, fatal and 

serious injury crashes, or percent changes in crash frequency or severity. Safety performance 

(e.g., crash frequency or crash severity) of alternative transportation networks under consider

ation can be estimated and compared to each other to evaluate safety conditions under differ

scenarios. The differences in safety performance between the various transportation networ

should then be considered as one of the decision factors along with the differences in traffi c 

operations (e.g., level of service), environmental impacts (e.g., air quality), or neighborhood 

livability (e.g., pedestrian access to transit).

This section discusses how agencies can use tools in the HSM to evaluate safety performance 

and support the integration of safety explicitly in long range transportation plans and more 

specifi cally in corridor studies. State departments of transportation have safety analysis busi

ness units that may be able to provide support to local agencies in acquiring the data and/or 

conducting safety analysis.

2 NCHRP 541: Consideration of Environmental Factors in Transportation Systems Planning, page 9. 
10

pp/pp

crash modifi cation factors (CMF) quantifying the effects of changing driveway density on urb

and suburban arterials. Or if a community is considering a “roundabout fi rst” policy, CMFs 

related to roundabouts and the effects of changing intersection traffi c control to a roundabou

are provided in the manual.

If a community is undertaking a long range planning process to identify 20-year transportati

system needs, one of the early activities is to evaluate existing transportation conditions related 

mobility and accessibility, pedestrian and bicycle connectivity, and transit service. Part B of the 

HSM provides network screening methods to identify sites with potential for safety improvem

These sites can be evaluated to identify specifi c improvements and subsequently prioritized 

alongside other sites with particular capacity, operational, or connectivity needs. The agency 

can then use the results from this process to develop a prioritized list of sites for project programming and forward some of these projects into the regional planning process.

NCHRP 546: Incorporating Safety Into Long Range Transportation Planning demonstrates the feas

bility of estimating the safety performance of different transportation networks at the transp

tation analysis zone (TAZ) level. While not part of the HSM, the concepts from this research 

could be used as part of the future network evaluation stage of a long range transportation pl

Future versions of the software PlanSafe will simplify implementing these concepts.

2. Integrating the Highway Safety Manual into Corridor Planning

As an outcome of the long range planning process, an agency may undertake a refi ned corrid

specifi c plan. In this type of project, the effort may be focused on evaluating alternative cros

sections, functional classifi cations, access management concepts, use of a context-sensitive 

solutions, etc., for a specifi c corridor. For example, it may be that a community’s long range p

identifi ed the need for additional roadway capacity in a corridor without specifi c details on th

proposed facility. The corridor-specifi c plan would examine additional considerations related 

the corridor cross-section and interaction with adjoining land uses and stakeholders needs. 

Options for medians (including type and location), number of lanes, and/or provision of on-str

parking are among the issues that may be considered in this process.

The HSM predictive method can be used to estimate the changes in crash frequency of many 

these geometric features for different facility types. Alternatively, an agency can estimate the 

infl uence of the type and frequency of intersections, driveways, parking, or median types on 

the crash frequency for an urban or suburban arterial. Such information may be useful in 

assessing the effects of different land use plans for a subarea, each requiring a different road 

network characteristic
11

screening methods (listed in Chapter 4, Part B of the HSM) to identify sites or corridors with 

potential for safety improvement. The agency can use this tool to screen the transportation 

network or part of the network, where the minimum required data are available for the analy

sis. For more information, visit http://www.safetyanalyst.org. Other agency-specifi c or commercial software may be available or under development to incorporate some or all of the 

performance measures and screening methods in the HSM.

FHWA developed a case study showing how Ohio DOT is using AASHTOWare SafetyAnalys

to assist with all steps of their safety management system, including: network screening, 

diagnosis, countermeasure selection, economic appraisal, prioritization, and countermeasur

evaluation. More case studies can be found at http://www.safety.fhwa.dot.gov/hsm 

(FHWA 2012). 

The FHWA Safety Performance Measure Primer is also available as a resource to help identif

additional performance measures. http://www.safety.fhwa.dot.gov/hsip/tsp/fhwahep09043/

sources.cfm 

PlanSafe is a software tool that was developed through NCHRP. While macro-level safety 

prediction approaches (such as PlanSafe) are not included in the fi rst edition of the HSM, age

cies can use PlanSafe to compare differences in crash frequency or severity across different 

future development and network scenarios. More information about this tool is available at t

TRB web site. An updated version of the software is anticipated in the summer of 2012.

Tools to Support HSM Application in Corridor Planning

Spreadsheets are available to perform basic HSM 

predictive analysis. This includes the spreadsheets 

developed as part of the NCHRP 17 38 HSM Training 

Materials project for training purposes. The 

Alabama Department of Transportation (ALDOT) 

and Virginia Department of Transportation (VDOT) 

released a set of spreadsheets that extends the functionality and ease of use of the NCHRP 17 38 spreadsheets. These spreadsheet tools are available from 

the TRB Highway Safety Performance Committee 

web site: http://www.safetyperformance.org. Other 

states, such as Illinois and Washington developed 

state-specifi c spreadsheet tools that can be used for 

corridor planning.

Most state departments of transporta

tion have some type of safety analysi

and/or crash data analysis unit. This 

group will manage statewide safety 

programs such as the state Strategic 

Highway Safety Plan. The group may 

also manage safe routes to schools, 

safety belts, commercial vehicle, or 

impaired driving programs. Most 

states will also have traffi c records/

data analysis units that work with 

state crash data records. The staff in 

data analysis units and the safety 

analysis units can be called upon to 

support local efforts to integrate safe

into planning.
12

range transportation plan. The example application introduces a hypothetical scenario to 

demonstrate an application of the HSM as part of a set of example discussions in subsequent 

sections. The examples in this guide are not provided to demonstrate how to perform the 

analysis but rather demonstrate how applying the HSM may be integrated into existing planning, design, and evaluation processes.

An MPO is developing their regional transportation plan. The local agency is conducting the 

needs assessment phase of the project. In addition to the pedestrian, bicycle, and congestion 

assessment, the MPO has conducted a network screening analysis on the major roadway systems (freeways and arterials) to identify particular corridors with potential for safety improv

ment. The MPO selected two performance measures from the HSM: equivalent property-da

age only (EPDO), and excess expected crash frequency. Using the peak searching method, th

analysis identifi ed roadway segments where reported crashes exceeded the expected number 

crashes based on the characteristics of the roadway and the safety performance function asso

ated with that roadway type. This method took into account the variation in crash data from 

year to year. The agency identifi ed several corridors that may benefi t from investment and 

prioritized the corridors. Exhibit 3 summarizes the results. They identifi ed the corridor on 

Route A, from milepost 5.6 to 8.1, as the corridor with the highest potential for safety improve

ment based on EPDO and excess expected crash frequency with forecasted future travel deman

The corridor will be studied further as part of the next stage in the regional planning process

EXHIBIT 3

Example Application of the HSM in System Planning

Corridor Description

EPDO Score

(PDO crashes per year)

Excess Expected Average 

Crash Frequency

(fatal and injury crashes per ye

Route A, milepost 5.6 to 8.1 92 45

Route E, milepost 0 to 1.3 38 35

Route C, milepost 72.1 to 90.0 41 28
13

eeets ote poga. poject wbe deted to ove owad wta set poject 

scope. The project scope includes defi ned limits, resource budget and a schedule for eventua

completion including construction.

Every project has a fundamental purpose or objective, typically refl ecting the identifi ed planning needs, such as providing improvements to mobility for a corridor or subarea, addressing 

infrastructure repair or rehabilitation based on input from asset management data, enabling 

expansion of modal choice (e.g., bus, bicycle, etc.), or improvements to address a public safety 

concern. Any of these objectives may be expressed as a project’s purpose and need in an 

environmental evaluation document, also referred to as a NEPA document.

Once a project’s scope and “purpose and need” are established, the project can move to the 

critical step of Alternatives Development and Analysis. Best project development practices emph

size development of multiple alternatives within the project scope, one of which is typically a 

“no-build” alternative.

As alternatives are proposed, they are fi rst evaluated 

against the stated purpose and need. Multiple 

alternatives may be viable but may differ in meaningful ways that relate to their footprint, impacts to 

adjacent land use, design characteristics, traffi c operational quality, and safety performance.

Within this typical project development process, 

agencies can apply the HSM to support explicit 

consideration of quantitative safety during alternatives development and analysis. In this stage of the 

project development process, agencies proceed with a 

detailed engineering and environmental analyses of 

each alternative, in an effort to understand the specifi c costs, impacts and attributes. This analysis will 

provide decision-makers with objective data to 

inform the decision on a preferred alternative, which 

is typically documented in a Categorical Exclusion 

(CE), or an Environmental Impact Statement (EIS).

In the past, agencies and technical professionals were readily able to assess project impacts b

applying quantitative tools and methods to estimate measures of noise and air quality, wetlands, threatened and endangered species, and an array of other features important to society

Similarly, through the methodologies established in the Highway Capacity Manual (HCM), 

“NEPA analysis frequently assumes 

safety will be maximized solely through 

adherence to roadway design standards. 

Yet traffi c crashes continue to be a 

fre-quent occurrence, even on newly 

con-structed roadways; and nationally, 

tens of thousands die each year in traffi c 

crashes. Addressing this problem require

considering more than standards to 

maximize the safety of new transportati

projects.”

Integrating Road Safety into NEPA 

Analysis: A Primer for Safety and 

Environmental Professionals 

(FHWA 2011).
14

section focuses in particular on the use of the HSM in the NEPA process, the HSM can be use

in a similar way for any project, regardless of whether a formal environmental process is 

required or not.

2. Applying the HSM in Environmental Analysis

Projects requiring environmental analysis, as directed by the National Environmental Policy 

Act (NEPA), can particularly benefi t from the use of the HSM in the following activities:

• Defi ne purpose and need for the project.

• Defi ne and refi ne the range of project alternatives.

• Analyze alternatives.

• Evaluate alternatives.

• Select alternative for implementation.

Exhibit 4, from the FHWA Practitioners’ Primer: Integrating Road Safety into NEPA Analysis

(2011), demonstrates the opportunities for integration of safety into NEPA analysis.

Defi ne purpose and need for the project. Purpose and need statements can refer to providing or 

enhancing mobility, repairing or replacing infrastructure in poor condition, addressing moda

choice, or improving safety. While most projects do not identify safety as a primary purpose 

and need, the HSM provides methods for agencies to objectively defi ne locations or projects f

which the potential for safety improvement is indeed signifi cant. For projects with safety as 

primary driver, the tools and methods in the HSM allow agencies to identify historic crash 

characteristics and probable contributing factors to crashes, particularly fatal and serious inju

crashes. An agency can use the predicted method in the HSM to calculate the historic and 

anticipated future safety performance (calculated using the predictive methods in the HSM) 

and the fundamentals of human factors in the HSM to identify safety-specifi c needs for a 

project and estimate the potential for safety improvement. Such an approach increases the 

likelihood that safety investments will be cost-effective. For other projects with different 

purpose and need statements, the HSM still has value as discussed below.
15

Source: FHWA, Integrating Road Safety into NEPA Analysis, 2011.

Determine project scope. An important part of a project’s scope is the designation of the type 

project. This designation translates to applicable design criteria. For projects involving an 

existing road in need of some improvement, there are two fundamental project types, reconstruction and rehabilitation. Reconstruction is associated with major change to the road cros

section, alignment, or both. Applicable design criteria often exceed that of the older road, 

necessitating signifi cant and costly reconstruction. Most agencies have adopted alternative 

design criteria for road projects primarily driven by infrastructure repair, referred to by som

as “3R” criteria (resurfacing, restoration, and rehabilitation). However, the use of full reconstruction criteria is often promoted as necessary or desirable to enhance safety. With adoptio

of tools and methods in the HSM, agencies can incorporate the historic safety performance of t

existing road into their decision on the designation of project type. By designating a project a

“3R” based on a review of its historic safety performance compared with expected performa

per HSM information, agencies can reduce project costs and impacts by avoiding more costly 

reconstruction aimed at improving safety, when no such improvement is expected.

Defi ne and refi ne the range of project alternatives. The HSM can support the identifi cation of lik

reasonable alternatives. Documentation for NEPA requires a discussion of the approach and 

rationale for selecting the reasonable alternatives for detailed analysis and an explanation for 

Environmental

Consequences

Alternatives

Analysis

Affected

Environment

Mitigation

Purpose-and-Need

Propose mitigation to

address safety impacts

Evaluate safety 

impacts

Evaluate safety 

performance

Include safety; link to 

safety planning 

processes

Define the context

Include

safety

stakeholders

Provide

safety

analysis to

the public
16

alternatives may be negligible or even adversely affect safety performance, the agency can 

eliminate some alternatives initially considered. The information derived from the HSM cou

then be part of the documentation needed to support the elimination of these alternatives.

Analyze alternatives. Tools and methods in the HSM support quantifying safety performance 

during alternative analysis. For urban and suburban arterials, the predictive method in the 

HSM offers the ability to assess the impacts of changes in geometric features or traffi c volum

on pedestrian and bicycle crashes.

Evaluate alternatives. The predictive methods in the HSM Part C provide the ability to quantif

the anticipated safety performance for each alternative in terms of its anticipated crash 

frequency and severity. This evaluation can also include comparison with a no-build alterna

tive and, if desired, translation of crash reductions into economic benefi ts based on guidance 

Part B of the HSM.

Select alternative for implementation. For the fi rst time, agencies are now able to make relative 

comparisons between alternatives based on the number of crashes or combinations of particu

crash severities by using the predictive methods of Part C of the HSM. In the event that agen

cies select an alternative that does not have the highest predicted safety performance 

(e.g., because environmental or other impacts were greater for the particular geometric confi g

ration), agencies can use the HSM to identify safety mitigation strategies to increase safety 

performance for the selected alternative.

Project decision making can be complex. It inherently involves tradeoffs among alternatives 

with differing performance attributes. Using the HSM to inform the decision making proces

does not place any requirements on an agency to select the alternative with the best safety 

performance any more than would making a decision solely based on capital cost. 

Furthermore, absent application of HSM and quantifi cation of safety, the decision-maker has 

way of knowing what if any safety tradeoffs exist.

The HSM is neither intended to be, nor does it establish, a legal standard of care for users or 

professionals. No standard of conduct or any duty toward the public or any person shall be 

created or imposed by the publication and use or nonuse of the HSM. Documentation used, 

developed, compiled or collected for analyses conducted in connection with the HSM may be 

protected under Federal law (23 USC 409).
17

gg 

project right-of-way costs.

More information about this case study is available at http://www.safety.fhwa.dot.gov/hsm/

casestudies/fl _cstd.pdf (FHWA 2012).

Agencies can select from a variety of tools to perform a predictive analysis using the HSM. 

FHWA developed the IHSDM software tool that can perform several other analyses that are o

value during the alternatives analysis process. More information is available at http://www.

ihsdm.org. Agencies can also use spreadsheets to perform basic HSM predictive analysis. Th

NCHRP 17 38 spreadsheets and those from ALDOT and VDOT are available on-line from the 

TRB Highway Safety Performance Committee web site: http://www.safetyperformance.org. 

Other states, such as Illinois and Washington have developed state-specifi c spreadsheet tools 

that these agencies use during alternatives development and analysis.

The FHWA CMF Clearinghouse is an on-line, free database of CMFs to quantify the impact of 

treatments. Agencies can query the database on-line at http://www.cmfclearinghouse.org. 

FHWA updates the Clearinghouse regularly.

4. Example Application: Alternative Analysis

This example application continues the hypothetical example presented in Section II.

The MPO is now conducting a corridor study, consistent with NEPA requirements, on the corridor 

selected (Route A) with potential for safety improvement. The following demonstrates how such a stud

might be conducted and how the results might be summarized in a NEPA document.
18

Source: (Graphics: CH2M HILL).

Note: The project information and analysis results in these examples are hypothetical and for illustratio

purposes only. It does not refl ect results from an actual analysis nor does it intends to serve as an exam

of the relative anticipated safety performance of these three alternatives for an actual project.

The agency used the HSM Part C to assess the current and future anticipated safety performance for th

no-build conditions, Alternative 1, and Alternative 2.

, pp

• Five lanes and 14-foot center two-way left-turn lane

• On-street parallel parking

• Sidewalk exists, 3 feet minimum in some locations 

Alternative 1 Facility Description:

• Urban arterial

• Commercial land use

• Partial, four lanes with raised 14-foot median

• Partial, fi ve lanes with center two-way left-turn lane

• Remove on-street parallel parking

• Provide bus pullouts at selected locations

• Modify to 12-foot sidewalk with 4-foot landscaped buffer 

 Alternative 2 Facility Description:

• Urban arterial

• Commercial land use, and consolidated driveways

• Two lanes in each direction with dedicated HOV lane

• Additional right-of-way for raised median and left-turn pockets at 

specifi c locations along entire corridor

• Remove on-street parallel parking

• Provide bus pullouts at selected locations

• Four-foot landscaped buffer with 5-foot pedestrian path
19

driveways along the most southern section of the corridor.

The agency used the predictive method in Chapter 12 of the HSM Part C to 

quantify the safety performance (expressed in crashes in this example) for 

the existing and future traffi c volumes for the current corridor confi guration. 

This method accounts for the presence of on-street parking, the particular 

driveway density of the project, and the presence of the two-way left-turn lane. 

The agency used the analysis results and updated the Purpose and Need 

Statement, so that it specifi cally refers to the need to reduce the fatal and serious injury crashes involving parked vehicles and left-turning vehicles on the 

southernmost section of the corridor.

Alternative 1 The agency used the predictive method in Chapter 12 of the HSM Part C to 

identify the crash frequency associated with Alternative 1 compared to the 

no-build option. Alternative 1 represents the following changes from 

the no-build:

• Removal of on-street parallel parking,

• Use of street-trees,

• Consolidation of a subset of driveways on a particular part

of the corridor, and

• Installation of a median where left-turning driveway-related 

crashes areoverrepresented.

The FHWA CMF Clearinghouse provides insight into the likely impact of dedicated bus pullout locations along the corridor.

Alternative 2 The agency used the predictive method in Chapter 12 of the HSM Part C to 

estimate the change in crash frequency associated with Alternative 2 compared to the no-build option. Alternative 2 represents the following changes 

from the no-build: more comprehensive consolidation of driveways (as 

compared to Alternative 1) and a raised median throughout the corridor with 

left-turn pockets at predetermined locations.

• Note: The agency did not consider the HOV as a lane that adds capacity 

(additional general-purpose volume). 
20

Discussion of results: It is anticipated that the existing facility will experience, 

on average, 110 fatal and injury crashes per year in 2025. A corridor with 

similar volumes and characteristics is anticipated to experience, on average, 62 crashes per year. The no-build option has an average potential for 

improvement of 48 fatal and injury crashes per year.

Alternative 1 Nexpected = 65 fatal and injury crashes per year

Discussion of results: It is anticipated that the existing facility will experience, 

on average, 65 fatal and injury crashes per year in 2025. A corridor with similar volumes and characteristics is anticipated to experience, on average, 45 

fatal and injury crashes per year, indicating an anticipated average potential 

for improvement of 20 fatal and injury crashes per year. Alternative 1 is anticipated to experience 45 fewer fatal and injury crashes on average per year 

than the no-build option.

Alternative 2 Nexpected = 45 fatal and injury crashes per year

Discussion of results: It is anticipated that the existing facility will experience, 

on average, 45 fatal and injury crashes per year in 2025. A corridor with 

similar volumes and characteristics is anticipated to experience, on average, 

34 crashes per year, indicating an anticipated average potential for safety 

improvement of 20 fatal and injury crashes per year. Alternative 2 is anticipated to experience 65 fewer fatal and injury crashes on average per year than 

the no-build option, and 20 fewer fatal and injury crashes on average per year 

when compared to Alternative 1.

± Nexpected represents the anticipated expected average crash frequency.3

Based on Exhibit 7 the agency concludes:

• Without improvement, it is anticipated the no-build alternative will experience, on average, 110 fatal and inj

crashes per year in 2025.

• If the agency implements Alternative 1, on average, 65 fatal and injury crashes per year in 2025 are anticipa

to occur.

• If the agency implements Alternative 2, on average, 45 fatal and injury crashes per year in 2025 are anticipa

to occur.

• The difference in safety performance between the no-build and Alternative 1 is 45 average fatal and injury 

crashes on the corridor per year in 2025.

• The difference in safety performance between Alternative 1 and Alternative 2 is 20 average fatal and injury 

crashes on the corridor per year in 2025.

3 The HSM defi nes the expected average crash frequency as the number of crashes anticipated per year, if 

long-term average number of crashes at a site could be determined for a particular site (a segment or 

intersection) with a given set site conditions. 
21
22

design speed).

Historically, the geometric design criteria have been viewed as the means by which an accept

able level of safety is provided. However, as FHWA and AASHTO both note (Flexibility in 

Design, AASHTO Guide to Achieving Flexibility in Design) the basis behind geometric criter

includes many factors, (e.g., cost, maintainability, traffi c operations) with safety being just one

Moreover, two designers using the same controls and same criteria may create two different 

alignment and cross-section solutions, with different expected safety performance.

With the HSM, the designer is now able to develop solutions based not just on design criteria

but also on quantitative safety performance, as measured by crash frequency and severity 

alongside operational and project-specifi c considerations. The designer can also apply scienc

based human factors fundamentals from Chapter 2 in the HSM to identify and assess design 

solutions based on user abilities and limitations. As a result, the HSM now allows agencies to 

perform what is referred to as “safety performance-based design.”

This section discusses three such activities that agencies may implement to explicitly conside

safety in design:

• Assess the safety impact of a design parameter.

• Evaluate the impact of design exceptions on safety performance.

• Review implemented projects to evaluate impacts of design criteria.

Assessing safety impact of a design parameter. During the design process, the designer conside

options across multiple geometric elements (e.g., lane and shoulder width, curve radii, grade, 

etc.). The geometric, cross-section, and other project features are selected based on the applicable design criteria, with the primary goal of meeting the project-specifi c needs in a cost-effe

tive manner. This design process involves choices and tradeoffs. While design manuals and 

standards are important in this process, balancing quantitative, science-based safety impacts 

a design parameter against traffi c operations and cost, allows the designer to make overall 

cost-effective system performance choices. With the HSM tools and approaches, designers ca

prepare preliminary plans, evaluate their safety performance, refi ne or adjust one or more 

elements and reevaluate the performance in a manner similar to balancing cut and fi ll. The 

inclusion or exclusion of features such as medians can be tested for safety performance. The 

predictive method and the CMFs in the HSM provide insight into the impact of individual 

parameters for particular highway types, as well as individual treatments.
23

exception in terms of crash frequency or severity. This allows for a quantitative assessment o

the relative impact of the exception. If a particular exception affects the safety performance o

project negatively, and there is a desire to proceed with the project, CMFs in the HSM may of

options for mitigation. FHWA’s publication Mitigation Strategies for Design Exceptions

(FHWA-SA-07-011) describes how such analyses can be done. Finally, the design exception 

process includes documentation in the form of a report and acceptance by a responsible party 

such as an agency’s Chief Engineer. Documenting the basis for a design exception decision, 

including the quantitative safety analysis, is a valuable risk management tool for agencies.

Reviewing implemented projects to evaluate impacts of design criteria. Agencies regularly update 

geometric design standards, guidelines, and criteria to refl ect advances in the science of oper

tions, safety, and other related fi elds. The evaluation methods discussed in Chapter 9 of the 

HSM offer approaches to evaluate projects or bundles of similar projects to quantify the impa

of variation in design criteria on safety performance. The HSM discusses different study 

designs, strengths and limitations of each, and particular considerations. By evaluating completed projects, agencies can update design criteria to incorporate and refl ect their relative 

impact on project safety performance, thus providing continual opportunity for proactive 

approaches to lower crash or injury risk on the system. There are HSM methods that account 

for regression-to-the-mean (RTM), and, therefore, provide more accurate estimates.

The tools used to quantify safety performance in the activities described above are similar to 

those used in alternative identifi cation and analysis (see Section III).

2. Design Decisions and the HSM

The HSM does not require agencies to select a particular solution purely because it has the 

lowest associated crash frequency or severity. However, the tools in the HSM allow agencies 

review a selected alternative (that may not have had the lowest associated crashes or severity

and evaluate opportunities to improve safety performance by using Part C or Part D of the HSM
24

pated to have AADTs in excess of 25,000 vehicles per day. In addition the DOT requires multimodal integration a

part of project development process.

Based on an environmental assessment of the alternatives presented in Section III, the local agency concludes t

additional public right-of-way required for Alternative 2 would adversely impact the environment. There are histo

buildings located next to the existing facility limiting the width available for consideration to extend the existing rig

of-way. In addition, the agency found that existing driveway confi gurations and legislation limits the ability of the 

local agency to consolidate private driveways as part of the project.

The agency selected Alternative 1 as the most feasible alternative. Because Alternative 1 does not meet all 

the design standards of the state (full median and consolidation of private driveways), the agency requested 

design exception.

The agency then used the HSM predictive method and CMFs to identify mitigation options for the impact of the 

design exceptions on safety performance in Alternative 1. The safety-related mitigation strategies the agency id

fi ed included:

• Consolidating selected number of driveways,

• Installing a raised median on the most southern section of the corridor where right-of-way is available and whe

the majority of fatal and severe left-turning driveway-related crashes historically occurred,

• Modifying the specifi cation for street trees alongside the corridor with species anticipated to have mature trunk 

diameters less than 3 inches and reducing the density of these trees along the corridor, and

• Replacing proposed street trees in the median with alternative vegetation that would not increase crash severi

outcomes or restrict sight distance.

Based on the predictive analysis the agency anticipates that Alternative 1 and the mitigation strategies for 

Alterative 1 will likely improve the safety performance of the corridor to an average of 45 fatal and serious injury 

crashes per year compared to the no-build alternative, which also equals the safety performance of Alternative 2
25

2012a). Operations include asset management; activities and technologies for managing and 

minimizing recurring congestion; reducing the risk and extent of nonrecurring congestion; 

managing incidents, weather events, construction work zones, or special events; integrating 

freight mobility and capacity needs into the system; and managing and mitigating day-to-da

traffi c operations as appropriate at intersections, and along roadway segments.

The HSM offers data driven and science-based methods and tools that can be used to monito

and identify treatments likely to improve the safety performance of the roadway network. T

following items represent typical applications:

• Identify measures agencies use to identify, quantify and evaluate safety performance acro

the system.

• Identify and implement countermeasures to reduce overall crash severity on corridors, 

segments, or intersections.

• Identify typical locations in a geographical region (local, county, or state level) that may 

particularly benefi t from systemic treatments to reduce overall crash severity and crash ri

such as systemically planning to install roundabouts.

• Identify and assess changes in safety performance for different operational conditions.

• Evaluate and quantify the impact of treatments, policies, and programs on the safety perf

mance of corridors, segments, intersections, groups of treatments, or the roadway networ

• Inform maintenance improvement policies and priorities.

The remainder of the section presents a discussion of each of these applications alongside 

applicable tools and HSM references.

1. Performance Measures

Chapter 4 of the HSM presents a number of alternative measures to quantify safety performance. While the HSM does not identify particular performance measures as preferred 

approaches, the manual outlines the strengths and limitations associated with each. Such 

information can be particularly useful in the selection of one or a combination of performanc

measures agencies use to quantify safety performance. While, crash frequency (from crash 

history) and crash rates were traditionally used as performance measures, the HSM presents 

performance measures with a higher reliability than these measures. Using a higher reliabili

performance measure increases the likelihood that locations most likely to benefi t from safet

treatments are selected for further evaluation.
26

reduce overall crash severity. Once countermeasures are identifi ed, the methods in Chapter 7 

the HSM can be used to assess the economic costs and benefi ts associated with each alternati

After an assessment of other impacts associated with each of the alternatives (e.g., environme

tal, public acceptance, and legislative framework) agencies can identify and implement the tr

ment or group of treatments at the particular location or group of locations. Chapter 8 of the 

HSM includes methods that an agency can use to prioritize a set of locations for treatment – a 

typical approach to support decision making within a particular program or fi nancial year.

Within operations, agencies often consider a collection of sites for typical improvements base

on similarity of characteristics and particular operational needs. These treatments may vary 

cost and operational impact. The HSM methods allow an agency to also include safety perfo

mance as criteria for selecting the sites and identifying treatments, particularly where the cra

experience suggest potential for safety improvement. Part D of the HSM or information from 

the FHWA CMF Clearinghouse may provide insight as to the safety impact of operationalbased changes. Examples may include, conversion of signalized intersections into roundabou

change in signal change intervals, changes in signal phasing (e.g., changing permissive to 

protected-permissive phasing, changes to phasing to a protected-permissive phasing with 

fl ashing yellow arrow for the permissive phase). When operational treatments also represent 

systemic safety treatments, implementation often offers a relatively low-cost solution to lower 

fatal and serious injury risk on the system.

Decisions in operations and maintenance often include assessments of anticipated changes in 

performance for different operational and site characteristics. The HSM and related tools 

allow an agency to assess the change in safety performance (measured in crash frequency an

severity) due to operational changes. For example, on high-volume freeway corridors should

running may be under consideration as a traffi c management strategy. Forthcoming HSM 

freeway research results provide information about the quantitative safety impacts of such 

operational changes. With the use of the HSM predictive method (and in this case the anticipated additional chapter on freeway safety prediction) agencies can quantify the relative cha

in crash frequency and severity for such alternatives. Part D of the HSM and the FWHA CM

Clearinghouse provide information for a variety of such alternatives.

Chapter 9 of the HSM presents state of the practice methods in safety performance evaluation. The

methods include methods that are associated with higher reliability than traditional approaches.

Once an agency implements operational changes to corridors or sites, Chapter 9 in the HSM c

be used to incorporate safety into monitoring activities at these treated sites. Results from th

evaluations may serve as input to accountability reports to the legislature and public.
27

Agencies often have to make tradeoffs between funding maintenance improvements to such 

items as pavement, roadside facilities (e.g., guardrail, signs, lighting), and bridge facilities. Th

HSM provides tools (i.e., crash modifi cation factors, and the predictive method) to quantify th

effects of maintenance decisions on changes in crash frequency or severity on the transportation system. This information could be extended to a benefi t/cost analysis using methods fr

Part B of the Highway Safety Manual. 
28

The HSM provides planners and engineers with quantitative tools to evaluate safety impacts 

and safety performance. Safety performance can be a meaningful consideration for both 

projects funded with safety-specifi c funding and projects funded with nonsafety funding. T

quantitative safety analysis tools in the HSM enables agencies to assess the likely effectivenes

of a project and justify investments for improving safety performance. Safety can now have 

equal standing in programmatic and design decision making along with asset condition, env

ronmental effects and costs.

The HSM also offers opportunities to include safety in performance measurement and perfor

mance-based design and implementation. Integrating the HSM and data driven performanc

based solutions into the day-to-day decision making processes at an agency will contribute to 

overall improvements in system performance.

Safety analysis tools to support HSM application are currently available and new versions ar

under development. These tools include, but are not limited to, AASHTOWare SafetyAnalyst

the IHSDM, and the FHWA CMF clearinghouse. Links to these and other tools are available 

the AASHTO Highway Safety Manual web site at http://www.highwaysafetymanual.org. 

Additional resources and training opportunities for the HSM are posted at the FHWA HSM 

web site located at http://www.safety.fhwa.dot.gov/hsm.

Integrating the HSM into agency processes and considerations, will support regional, state, a

national fatality reduction goals alongside the goals of mobility, the environment, and other 

competing needs.
29

impTA6640.asp.

FHWA, 2012a. FHWA About Operations Website, Washington, D.C., http://ops.fhwa.dot.gov/

aboutus/aboutus.htm.

FHWA, 2012b. FHWA Safety Program Website, Washington, D.C., http://safety.fhwa.dot.gov.

FHWA, 2012c. HSM Case Study 1: Using Predictive Methods for a Corridor Study in Idaho, Federa

Highway Administration: Offi ce of Safety, Washington, D.C., http://safety.fhwa.dot.gov/hsm

casestudies/id_cstd.cfm.

FHWA, 2012d. HSM Case Study 2: Implementing a New Roadway Safety Management Process with 

SafetyAnalyst in Ohio, Federal Highway Administration: Offi ce of Safety, Washington, D.C., 

http://safety.fhwa.dot.gov/hsm/casestudies/oh_cstd.cfm.

FHWA, 2012e. HSM Case Study 3: Using Predictive Methods for Alternative Selection in Florida, 

Federal Highway Administration: Offi ce of Safety, Washington, D.C., http://safety.fhwa.dot.

gov/hsm/casestudies/fl _cstd.cfm.

FHWA, 2012f. HSM Case Study 4: Development of Safety Performance Functions for Network 

Screening in Illinois, Federal Highway Administration: Offi ce of Safety, Washington, D.C., http

safety.fhwa.dot.gov/hsm/casestudies/il_cstd.cfm.

FHWA, 2012g. HSM Case Study 5: HSM Implementation Plans – New Hampshire DOT Experience

Federal Highway Administration: Offi ce of Safety, Washington, D.C., http://safety.fhwa.dot.

gov/hsm/casestudies/nh_cstd.cfm.

FHWA, 2011. FHWA Practitioners’ Primer: Integrating Road Safety into NEPA Analysis, Washing

D.C., http://safety.fhwa.dot.gov/hsip/tsp/fhwasa1136/fhwasa1136.pdf.

FHWA, 2011. Integrating Road Safety into NEPA Analysis: A Primer for Safety and Environmental 

Professionals, Federal Highways: Offi ce of Safety, Washington D.C., http://safety.fhwa.dot.gov

hsip/tsp/fhwasa1136/fhwasa1136.pdf.

Herbel, S., Laing, L., and McGovern, C., 2010. FHWA Highway Safety Improvement Program 

Manual, FHWA Offi ce of Safety, Washington, D.C., http://safety.fhwa.dot.gov/hsip/resources/

fhwasa09029/fhwasa09029.pdf.

McGovern, C., and Van Schalkwyk, I., 2010. HSM Training Guide, prepared for the Federal 

Highway Administration: Offi ce of Safety, Washington, D.C., http://safety.fhwa.dot.gov/hsm

training/hsmguide.pdf.
30

ggpjp

www.trb.org/Main/Blurbs/159691.aspx.

Neuman, T., and Van Schalkwyk, I., 2011. FHWA HSM Implementation Guide for Managers, 

prepared for the Federal Highway Administration: Offi ce of Safety, Washington, D.C., http://

safety.fhwa.dot.gov/hsm/hsm_mgrsguide/hsm_mngrguide.pdf.

Stein, W.J. and Neuman, T.R. 2007. Mitigation Strategies for Design Exceptions, prepared for 

Federal Highway Administration, Report No. FHWA-SA-07-011, Offi ce of Safety, Washington

D.C., http://safety.fhwa.dot.gov/geometric/pubs/mitigationstrategies/fhwa_sa_07011.pdf.
31

DOT State Department of Transportation (a general term used to describe the 

state agency that is responsible for the design and maintenance of the state 

transportation highway network)

FDOT Florida Department of Transportation

FHWA Federal Highway Administration

HSM Highway Safety Manual

HSIP Highway Safety Improvement Program

HSP State Section 402 Highway Safety Plan and Annual Performance Plan

IHSDM Interactive Highway Safety Design Model

NCHRP National Cooperative Highway Research Program

NCDOT North Carolina Department of Transportation

NEPA National Environmental Policy Act of 1969

SHSP Strategic Highway Safety Plan

SPFs Safety Performance Functions

TRB Transportation Research Board
U.S. Department of Transportation

Federal Highway Administration

Office of Safety E71-115

1200 New Jersey Avenue, SE

Washington, DC 20590

FHWA-SA-11-50