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This document is disseminated under the sponsorship of the U.S.

Department of Transportation in the interest of information exchange. The

U.S. Government assumes no liability for the use of the information

contained in this document. This report does not constitute a standard,

specification, or regulation.

The U.S. Government does not endorse products or manufacturers.

Trademarks or manufacturers’ names appear in this report only because

they are considered essential to the objective of the document.

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The Federal Highway Administration (FHWA) provides high-quality

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0BTechnical Report Documentation Page

1. Report No. FHWA-SA-06-17 2. Government

Accession No.

3. Recipient's Catalog No.

5. Report Date

December 2006

4. Title and Subtitle

Road Safety Audits: Case Studies 6. Performing Organization

Code

7. Authors

Margaret Gibbs; Sany R. Zein; Dan Nabors; Hugh McGee; Kim Eccles

8. Performing Organization

Report No.

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

Opus Hamilton Consultants Ltd

900 – 1199 West Hastings Street

Vancouver, B.C., Canada V6E 3T5

Vanasse Hangen Brustlin Inc

700 – 8300 Boone Boulevard

Vienna, VA 22182-2626

11. Contract or Grant No.

DTFH61-03-D-00105

13. Type of Report and Period

Covered

Final Report

Dec 2004 – April 2006

12. Sponsoring Agency Name and Address

Office of Safety

Federal Highway Administration

U.S. Department of Transportation

400 Seventh Street SW, HSA-20

Washington, D.C. 20590 14. Sponsoring Agency Code

15. Supplementary Notes: The Federal Highway Administration (Office of Safety) sponsored the RSAs

reported in this document. The FHWA Office of Safety Contract Task Order Manager was Louisa Ward.

16. Abstract

Road Safety Audits (RSAs) are an effective tool for proactively improving the future safety performance of a

road project during the planning and design stages, and for identifying safety issues in existing transportation

facilities. To demonstrate the effectiveness of RSAs, the Federal Highway Administration (FHWA) Office

of Safety sponsored a series of ten RSAs. The aim of these case studies was to demonstrate the usefulness

and effectiveness of RSAs for a variety of projects and project stages, and in a variety of agencies throughout

the United States.

The results of the RSAs have been compiled in this case studies document. Each case study includes

photographs, a project description, a summary of key findings, and the lessons learned. The aim of this

document is to provide state and local agencies and Tribal governments with examples and advice that can

assist them in implementing RSAs in their own jurisdictions.

17. Key Words

Safety, Road Safety Audit

18. Distribution Statement

No restrictions. This document is available to the public through

the National Technical Information Service, Springfield, VA

22161.

19. Security Classif. (of this report)

Unclassified

20. Security Classif. (of this page)

Unclassified

21. No. of

Pages: 64

22. Price

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

PREFACE

Road Safety Audits (RSAs) are an effective tool for proactively improving the

future safety performance of a road project during the planning and design stages,

and for identifying safety issues in existing transportation facilities. Additional

information on RSAs is available on the web at HUhttp://safety.fhwa.dot.gov/rsaUH and

HUwww.roadwaysafetyaudits.orgUH.

Information for the case studies reported in this document was gathered during a

series of ten RSAs conducted throughout the United States during 2004-2006,

involving transportation agencies at the city, county, state, federal, and tribal

levels, and examining roadway projects at all stages of design and operation.

FHWA and the authors greatly appreciate the cooperation of the following

agencies for their willing and enthusiastic participation in the FHWA-sponsored

RSA series: Illinois DOT, Oklahoma DOT, Oregon DOT, Wisconsin DOT, the

Standing Rock Sioux Tribe, the City of Cincinnati, the City of Tucson, Clark County

(WA), Collier County (FL), and the National Park Service.

ROAD SAFETY AUDITS: CASE STUDIES

TABLE OF CONTENTS

INTRODUCTION 1

Background 1

What is an RSA? 1

The FHWA RSA Case Study Program 3

THE RSA PROCESS 5

Eight Steps of an RSA 5

Prioritization of Issues for Design-Stage RSAs 8

RSAs: COSTS AND BENEFITS 10

RSA Costs 10

RSA Benefits 11

THE FHWA RSA CASE STUDY PROJECT: PROMOTING THE ACCEPTANCE OF RSAs 14

Key Factors for Success 14

Lessons Learned 19

CONCLUSION 22

APPENDIX A: CASE STUDY RSAs A-1

RSA 1 Illinois DOT A-2

RSA 2 Oklahoma DOT A-5

RSA 3 Oregon DOT A-8

RSA 4 Wisconsin DOT A-12

RSA 5 Clark County A-17

RSA 5 Collier County A-21

RSA 7 City of Cincinnati A-25

RSA 8 City of Tucson A-29

RSA 9 Standing Rock Sioux Tribe A-32

RSA 10 Yellowstone National Park A-36

LIST OF FIGURES

FIGURE 1 RSA PROCESS 5

FIGURE 2 START-UP MEETING 6

FIGURE 3 FIELD REVIEW 6

FIGURE 4 RSA ANALYSIS SESSION 7

FIGURE 5 PRELIMINARY FINDINGS MEETING 7

FIGURE 6 EXAMPLE DISCUSSION OF AN RSA SAFETY ISSUE 18
ROAD SAFETY AUDITS: CASE STUDIES

LIST OF TABLES

TABLE 1 CASE STUDY RSAs 3

TABLE 2 FREQUENCY RATING 9

TABLE 3 SEVERITY RATING 9

TABLE 4 CRASH RISK ASSESSMENT 9
ROAD SAFETY AUDITS: CASE STUDIES

1

INTRODUCTION

Background

Road Safety Audits (RSAs) are an effective tool for proactively improving the

future safety performance of a road project during the planning and design stages,

and for identifying safety issues in existing transportation facilities.

To demonstrate the effectiveness of RSAs, in December 2003 the Federal

Highway Administration (FHWA) Office of Safety sponsored a RSA of the

Marquette Interchange in Milwaukee, WI. The RSA team reviewed the detailed

design for an $800 million interchange reconstruction project. Subsequently, in

the summer of 2004, the FHWA Office of Safety commissioned a series of nine

additional RSAs. The aim of these case studies was to demonstrate the

usefulness and effectiveness of RSAs for a variety of projects and project stages,

and in a variety of agencies throughout the United States.

The results of the RSAs have been compiled in this case studies document. Each

case study includes photographs, a project description, a summary of key findings,

and the lessons learned. The aim of this document is to provide state and local

agencies and Tribal governments with examples and advice that can assist them

in implementing RSAs in their own jurisdictions.

What is an RSA?

A road safety audit (RSA) is a formal safety performance examination of an

existing or future road or intersection by an independent, multidisciplinary team.

Compromises and constraints among the competing interests that typically drive a

road project (such as cost, right of way, environment, topographic and

geotechnical conditions, socioeconomic issues, and capacity/efficiency) are a

normal part of the planning and design process. The design team has the

responsibility of integrating these competing interests to arrive at a design that

accommodates these interests in as balanced and effective a manner as possible.

RSAs, conducted by a team that is independent of the design, enhance safety by
ROAD SAFETY AUDITS: CASE STUDIES

2

explicitly and exclusively identifying the safety implications of project decisions. By

focusing on safety, RSAs make sure that safety does not “fall through the cracks”.

The RSAs followed the procedures outlined in the FHWA Road Safety Audit

Guidelines document (Publication Number FHWA-SA-06-06). The procedures

involve an eight-step RSA process discussed later in this case study document.

The multidisciplinary RSA team is typically composed of at least three members

having a background in road safety, traffic operations, and/or road design, and

members from other areas such as maintenance, human factors, enforcement,

and first responders. Members of the RSA team are independent of the

operations of the road or the design of the project being audited. The RSA team’s

independence assures two things: that there is no potential conflict of interest or

defensiveness, and the project is reviewed with “fresh eyes”.

RSAs can be done at any stage in a project’s life:

A pre-construction RSA (planning and design stages) examines a road

before it is built, at the planning/feasibility stage or the design (preliminary

or detailed design) stage. An RSA at this stage identifies potential safety

issues before crashes occur. The earlier a pre-construction RSA is

conducted, the more potential it has to efficiently remedy possible safety

concerns.

Construction RSAs (work zone, changes in design during construction, and

pre-opening) examine temporary traffic management plans associated with

construction or other roadwork, and changes in design during construction.

RSAs at this stage can also be conducted when construction is completed

but before the roadway is opened to traffic.

A post-construction or operational RSA (existing road) examines a road that

is operating, and is usually conducted to address a demonstrated crash

problem.
ROAD SAFETY AUDITS: CASE STUDIES

3

The FHWA RSA Case Study Program

The ten RSAs conducted in this case study program are summarized in Table 1.

TABLE 1 CASE STUDY RSAs

FACILITY OWNER PROJECT RSA STAGE

State Departments of Transportation

Illinois DOT improvement to four-lane arterial road preliminary design stage

and existing roads

Oklahoma DOT widening and resurfacing of two-lane rural

highway detailed design stage

Oregon DOT improvements to two-lane rural highway conceptual design stage

Wisconsin DOT replacement of major interstate interchange detailed design stage

Counties

Clark County, WA road alignment and intersection

improvements to two-lane rural road detailed design stage

Collier County, FL widening of four-lane arterial road planning stage

Cities

Cincinnati, OH

improvements to commuter arterial,

including bridge widening and intersection

improvements

planning stage

and existing roads

Tucson, AZ six pedestrian crossings with HAWK signals detailed design stage

Tribal

Standing Rock Sioux

Tribe, ND/SD existing two-lane rural tribal roads existing roads

Federal Lands

Yellowstone National

Park, WY

replacement of existing interchange with

new access

planning stage

and existing roads

All participating transportation agencies volunteered to be involved in this RSA

program. Involvement in the case study program required the agency to nominate

the project for the RSA; provide the RSA team with the materials (such as design

drawings) on which the RSA would be based, or that provided useful background

information, such as justification reports, traffic counts, collision data, or the results

of public hearings; participate at a senior level in the RSA start-up and closing

meetings; and contribute at least one engineer from their staff, not previously

involved in the project, to participate on the RSA team. The RSA teams were led

by two experienced and independent consultants.

Information on each of these RSAs, including background, a summary of RSA

issues, and a list of suggested improvements, is included in the Appendix.
ROAD SAFETY AUDITS: CASE STUDIES

THE RSA PROCESS

Eight Steps of an RSA

The eight steps of an RSA are shown in Figure 1, and are discussed below with

reference to the case studies.

FIGURE 1 RSA PROCESS

RSA projects and the RSA team (Steps 1 and 2) were pre-selected in this FHWA

case studies project. All meetings and site visits for the RSAs in the case studies

project were conducted over two to four days, depending on the size and

complexity of the project. The RSAs typically began with a start-up meeting

(Step 3) attended by the Project Owner (hereafter referred to as the Owner), the

Design Team, and the RSA team:

4
ROAD SAFETY AUDITS: CASE STUDIES

5

The Owner described the objectives of the road project, including why it

was being pursued and the improvements it was expected to accomplish.

The Owner also explained why this project had been chosen for an RSA.

The Design Team then described the road design (if the RSA was being

conducted on a design), including a description of its individual elements;

the current design stage and anticipated design/construction schedule; and

the constraints and challenges involved in the design.

The multidisciplinary RSA team then described the RSA process. This

included an overview of the RSA process with examples of safety issues

that are typically encountered and mitigation measures to address them.

Illinois DOT Standing Rock Sioux Reservation

FIGURE 2

START-UP MEETING

FIGURE 3

FIELD REVIEW

Following the start-up meeting and a preliminary review of the design or site

documentation provided by the Owner and Design Team, the RSA team

conducted a field review (Step 4). The purpose of the field review was to observe

the ambient conditions in which the proposed design would operate (for designstage RSAs), or to observe geometric and operating conditions (for RSAs of

existing roads). The RSA team observed road user characteristics (such as

typical speeds and traffic mix), surrounding land uses (including traffic and

pedestrian generators), and link points to the adjacent transportation network.

Field reviews were conducted by the RSA team under a variety of environmental

conditions (such as daytime and night-time) and operational conditions (such as

peak and non-peak times).
ROAD SAFETY AUDITS: CASE STUDIES

The team conducted the RSA analysis (Step 5) in a setting in which all team

members reviewed available background information (such as design criteria,

project/justification reports, traffic volumes, and any relevant collision data) and

drawings. The RSA analysis methodology involved a systematic review of design

drawings, examining features such as road geometry, sight distances, clear zones,

drainage, signing, lighting, and barriers. Human factors issues were also

considered by the RSA team, including road and intersection “readability”, sign

location and sequencing, older-driver limitations, and driver perception of

geometric features constructed to minimum standards. On the basis of this review

of drawings, reports, and information obtained during the field review, the RSA

team identified and prioritized safety issues, project features that could contribute

to a higher frequency and/or severity of crashes. For each safety issue, the RSA

team generated a list of possible ways to mitigate the crash potential.

At the end of the analysis session, the Owner, Design Team, and RSA team

reconvened for a preliminary findings meeting (Step 6). Presenting the

preliminary findings verbally in a meeting gave the Owner and Design Team the

opportunity to ask questions and seek clarification on the RSA findings, and also

provided a useful forum for the Owner and Design Team to suggest additional or

alternative mitigation measures in conjunction with the RSA team. The discussion

provided practical information that was subsequently used to write the RSA report.

Marquette Interchange RSA (Milwaukee, WI) Collier County, FL

FIGURE 4

RSA ANALYSIS SESSION

FIGURE 5

PRELIMINARY FINDINGS MEETING

6
ROAD SAFETY AUDITS: CASE STUDIES

7

In the weeks following the on-site portion of the RSA, the RSA team wrote and

issued the RSA report (also part of Step 6) to the Owner and Design Team

documenting the results of the RSA. The main contents of the RSA report were a

prioritized listing and description of the safety issues identified (illustrated using

photographs taken during the site visit), with suggestions for improvements.

The Owner and Design Team were then encouraged to write a brief response

letter (Step 7) containing a point-by-point response to each of the safety issues

identified in the RSA report. The response letter identifies the action(s) to be

taken, or explains why no action would be taken. The formal response letter is an

important “closure” document for the RSA. As a final step, the Owner and Design

Team use the RSA findings to identify and implement safety improvements as and

when policy, manpower, and funding permit (Step 8).

Prioritization of Issues for Design-Stage RSAs

For design-stage RSAs, a prioritization framework was applied in both the RSA

analysis and presentation of findings. The likely frequency and severity of crashes

associated with each safety issue were qualitatively estimated, based on team

members’ experience and expectations. Expected crash frequency (Table 2) was

qualitatively estimated on the basis of expected exposure (how many road users

would likely be exposed to the identified safety issue?) and probability (how likely

was it that a collision would result from the identified issue?). Expected crash

severity (Table 3) was qualitatively estimated on the basis of factors such as

anticipated speeds, expected collision types, and the likelihood that vulnerable

road users would be exposed. These two risk elements (frequency and severity)

were then combined to obtain a qualitative risk assessment on the basis of the

matrix shown in Table 4. Consequently, each safety issue was prioritized on the

basis of a ranking between A (lowest risk and lowest priority) and F (highest risk

and highest priority). It should be stressed that this prioritization method was

qualitative, based on the expectations and judgment of the RSA team members,

and was employed to help the Owner and Design Team prioritize the multiple

issues identified in the RSA.

For each safety issue identified, possible mitigation measures were suggested.

The suggestions focused on measures that could be cost-effectively implemented

at the current design stage.
ROAD SAFETY AUDITS: CASE STUDIES

8

TABLE 2 FREQUENCY RATING

ESTIMATED

EXPOSURE PROBABILITY

EXPECTED CRASH FREQUENCY

(per RSA item)

FREQUENCY

RATING

high high

medium high

10 or more crashes per year Frequent

high medium

medium medium

low high

1 to 9 crashes per year Occasional

high low

low medium

less than 1 crash per year, but more than

1 crash every 5 years Infrequent

medium low

low low

less than 1 crash every 5 years Rare

TABLE 3 SEVERITY RATING

TYPICAL CRASHES EXPECTED

(per RSA item)

EXPECTED CRASH

SEVERITY

SEVERITY

RATING

crashes involving high speeds or heavy

vehicles, pedestrians, or bicycles

probable fatality or

incapacitating injury Extreme

crashes involving medium to high speed;

head-on, crossing, or off-road crashes moderate to severe injury High

crashes involving medium to low speeds;

left-turn and right-turn crashes minor to moderate injury Moderate

crashes involving low to medium speeds;

rear-end or sideswipe crashes

property damage only or

minor injury Low

TABLE 4 CRASH RISK ASSESSMENT

FREQUENCY SEVERITY RATING

RATING Low Moderate High Extreme

Frequent C D E F

Occasional B C D E

Infrequent A B C D

Rare A A B C

Crash Risk Ratings: A: lowest risk level C: moderate-low risk level E: high risk level

B: low risk level D: moderate-high risk level F: highest risk level
ROAD SAFETY AUDITS: CASE STUDIES

9

RSAs: COSTS AND BENEFITS

RSA Costs

Three main factors contribute to the cost of an RSA:

RSA team costs,

design team and owner costs,

costs of design changes or enhancements.

The RSA team costs reflect the size of the team and the time required for the

RSA, which in turn are dependent on the complexity of the RSA project. For the

RSAs in this case studies project, the following cost components are noted:

RSA teams were composed of between four and ten persons in this case

studies project, but these teams were large since the RSAs served as

training exercises for local engineering staff. Without the need for training,

the RSA teams would more typically have been composed of three or four

persons.

Opening and closing meetings, site visits, and RSA analysis sessions were

conducted in a three-day period for each RSA.

Prior to and following the on-site portion of the RSA, the time required for

analysis (such as analysis of collision records, and research on applicable

design standards or mitigation measures) and writing the RSA report

ranged between 20 and 55 man-hours, with 30 to 40 man-hours being

typical. The wide range primarily reflected the number and complexity of

the issues identified during the RSA.

For this case studies project, additional RSA team costs were incurred in travel for

experienced RSA team leaders. However, typical RSAs would employ local team

members, and consequently entail only minor travel costs.

The design team and owner costs reflect the time required for staff to attend the

start-up and preliminary findings meetings, and to subsequently read the RSA
ROAD SAFETY AUDITS: CASE STUDIES

10

report and respond to its findings. In addition, staff time is required to compile

design drawings and other project or site materials for the RSA team.

The final cost component is that resulting from design changes or enhancements,

which reflect the number and complexity of the issues identified during the RSA.

Suggested design changes and enhancements, listed in the Appendix (Tables A.1

through A.12) for each of the RSAs conducted for this case studies project, have

focused on low-cost improvements or countermeasures where possible.

Suggested improvements for the four RSAs of existing roads focused

mainly on improved signing, signal enhancements, parking and access

management.

Suggested improvements for the four detailed-design RSAs focused on

improved signing and pavement markings, minor or moderate geometric

changes (such as added auxiliary lanes at intersections), and barrier

improvements. It should be noted, however, that one project owner initiated

a fundamental reconsideration of its entire project on the basis of the RSA

findings, which identified fundamental concerns regarding the net safety

benefits of the improvement project.

Suggestions for the preliminary and planning stage RSAs ranged from

minor improvements such as signing, through moderate geometric

improvements such as median and gateway treatments, to suggestions

related to fundamental issues such as design vehicles, design volumes,

and access restrictions.

RSA Benefits

The primary benefits of RSAs are to be found in reduced crash costs as road

safety is improved. The costs of automotive crashes are estimated by the US

Department of TransportationF

1

F as:

$3,000,000 for a traffic fatality,

$2,290,000 for a critical injury,

$565,000 for a severe injury,

$175,000 for a serious injury,

$45,000 for a moderate injury,

$6,000 for a minor injury.

1

Intersection Safety Issue Brief No. 15 (“Road Safety Audits: An Emerging and Effective Tool for Improved Safety”), issued

April 2004 by Federal Highway Administration and Institute of Transportation Engineers.
ROAD SAFETY AUDITS: CASE STUDIES

11

Other benefits of RSAs include reduced life-cycle project costs as crashes and the

need for retrofitted safety improvements are reduced, and the development of

good safety engineering and design practices, including integration of multimodal

safety concerns and consideration of human factors in the design.

As mentioned in the recent FHWA/ITE Intersection Safety Issue Brief on RSAs, it

is difficult to quantify the benefits of design-stage RSAs, since they aim to prevent

crashes from occurring on new or improved facilities that have no crash record.

However, when compared with the high cost of motor-vehicle injuries discussed

above, the moderate cost of a design-stage RSA suggests that changes

implemented from an RSA only need to prevent a few moderate- or high-severity

crashes for an RSA to be cost effective.

The benefits of RSAs on existing roads can be more easily quantified, since preand post-improvement collision histories are available. As an example, the Road

Improvement Demonstration Project conducted by AAA Michigan in Detroit and

Grand Rapids (MI), which is based on RSAs of existing high-crash urban

intersections and implementation of low-cost safety measures at them, has

demonstrated a benefit-cost ratio of 16:1.

Another example of U.S. data on the quantitative safety benefit of RSAs

conducted on existing roads comes from the New York DOT, which reports a 20 to

40 percent reduction in crashes at more than 300 high-crash locations that had

received surface improvements and had been treated with other low-cost safety

improvements suggested by RSAs.

The South Carolina DOT RSA program has had a positive impact on safety. Early

results from four separate RSAs, following one year of results, are promising. One

site, implementing four of eight suggested improvements, saw total crashes

decrease 12.5 percent, resulting in an economic savings of $40,000. A second

site had a 15.8 percent increase in crashes after only two of the thirteen

suggestions for improvements were incorporated. A third site, implementing all

nine suggested improvements, saw a reduction of 60 percent in fatalities, resulting

in an economic savings of $3,660,000. Finally, a fourth location, implementing 25

of the 37 suggested safety improvements, had a 23.4 percent reduction in

crashes, resulting in an economic savings of $147,000.
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12

The most objective and most often-cited study of the benefits of RSAs, conducted

in Surrey County, United Kingdom, compared fatal and injury crash reductions at

19 audited highway projects to those at 19 highway projects for which RSAs were

not conducted. It found that, while the average yearly fatal and injury crash

frequency at the RSA sites had dropped by 1.25 crashes per year (an average

reduction from 2.08 to 0.83 crashes per year), the average yearly fatal and injury

crash frequency at the sites that were not audited had dropped by only 0.26

crashes per hear (an average reduction from 2.6 to 2.34 crashes per year). This

suggests that RSAs of highway projects make them almost five times more

effective in reducing fatal and injury crashes.

Other major studies from the United Kingdom, Denmark, New Zealand, and

Jordan quantify the benefits of RSAs in different ways. However, all report that

RSAs are relatively inexpensive to conduct and are highly cost effective in

identifying safety enhancements.
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13

THE FHWA CASE STUDIES: PROMOTING THE ACCEPTANCE OF RSAs

The RSAs in this case studies project have been well received by all participating

agencies. Characteristics of the FHWA RSAs that have promoted their

acceptance by the participating agencies are generally those that are aimed at

making the RSA as useful and “user-friendly” as possible:

Key Factors for Success

1. The RSA suggestions have been consistent with the project’s design stage.

When a safety issue is identified by the RSA team, one or more possible mitigation

measures are suggested for consideration by the Design Team and Owner.

Suggested mitigation measures must be consistent with the design stage at which

the RSA is being conducted.

For example, an RSA was conducted on the detailed design of improvements to

US 60 in Oklahoma within 12 weeks of the date on which the final design was due

for submission. In the course of the RSA, the team identified a vertical crest curve

that limited sight distance to an intersection and driveways. Both the RSA team

and Design Team agreed that redesign of the road profile would improve sight

distance, but was infeasible financially and at such an advanced project stage,

when the land acquisition process had already been completed and utility

relocation was underway. The Design Team had already incorporated geometric

features to address the limited sight distance in the design, and the RSA team put

forward further mitigation measures that could feasibly be implemented at the

advanced design stage, such as signing and driveway relocation. Conversely, for

the RSA conducted at an early (planning) stage for widening an arterial roadway in

Collier County, FL, the RSA team could consider a wider range of safety

improvements that could feasibly be included in subsequent design stages.

Suggested measures included improved pedestrian and cycling facilities (since the

arterial was adjacent to newly constructed schools) and a comprehensive access

management program.
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14

2. Preliminary RSA results (findings and suggestions) have been presented to the

Owner twice, verbally and in a draft written form, to provide the Owner and Design

Team with the opportunity for input and review before the results are documented

in the final report.

Since RSA reports may become public documents, transportation agencies may

be sensitive to their contents and the way in which the RSA results are presented.

To address an agency’s concerns and provide it with an opportunity for input, the

RSA team first discusses the RSA results in the preliminary findings meeting. In

this discussion, the design team and the Owner have the opportunity to identify

potentially sensitive safety issues or alternative suggestions to those that have

been identified by the RSA team. In practice, the safety issues identified by the

RSA team in this case studies project have been consistently accepted as valid,

and no agency has attempted to discourage their inclusion in the RSA report. In

contrast, the RSA team’s suggestions for improvements were discussed at some

length.

After discussion in the preliminary findings meeting, a final set of suggestions can

be identified and incorporated in the RSA report. A draft version of the RSA report

is provided to the Owner for review. The Owner or Design Team can suggest

clarifications or provide additional information that can be incorporated in the final

RSA report. In practice, of the ten RSA reports completed to date in this case

studies project, changes to the draft have been requested in only three reports.

These changes were minor in nature, dealing with details such as terminology and

clarification of some transportation agency policies.

By discussing RSA findings in the preliminary findings meeting and issuing a draft

version of the report, the RSA team, Design Team, and Owner can work together

to ensure that potentially sensitive issues are appropriately presented. It remains

the responsibility of the RSA team to ensure that, while the Owner’s concerns are

adequately addressed, the final RSA report is an objective and accurate reflection

of its findings, and that the integrity and independence of the RSA process are

maintained.
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15

3. For RSAs at an early design stage, the RSA team has provided guidance on

possible low-cost improvements that could be implemented as interim measures to

decrease interim crash risks.

Two of the RSAs in this pilot series were conducted in the planning or preliminary

design stage, when construction was expected to start two or more years in the

future. In the interim, while waiting for the public consultation, design and funding

processes to proceed, the RSA team and Owner agreed that the safety issues that

had partly motivated the projects should be addressed. Accordingly, during field

reviews, the RSA team conducted an RSA of the existing facilities aimed at

identifying safety issues and low-cost countermeasures that could be implemented

as stopgap measures to improve safety as much as possible while waiting for the

redesign to be implemented. Representative stopgap improvements included

improved signing, improved pedestrian facilities (crosswalks and signal heads),

and a suggestion to review signal operations to determine if left-turn phasing

should be changed.

4. The RSA process has been applied to enhance the implementation of

innovative road safety measures, with the aim of promoting their success.

Transportation agencies may develop or adopt technologies or measures that are

innovative (locally or nationally) with the aim of promoting road safety. A common

example of such a measure is the modern roundabout. Since these measures

may be new to both the transportation agency and the wider community of road

users, they may involve unforeseen consequences that ultimately compromise,

rather than promote, safety. An RSA can be beneficial as a means of reviewing

the innovative improvement in its intended environment, identifying possible

factors that may compromise its successful implementation, and suggesting

measures to address them.

For example, the City of Tucson has developed an innovative pedestrian crossing

device, the HAWK signal (High Intensity Activated CrossWalK, a type of flashing

beacon), and is implementing it at intersections where pedestrian safety is a

concern. The City of Tucson received approval from FHWA to experiment with

this device; it is not yet adopted in the Manual of Uniform Traffic Control Devices.

One of the outcomes of the RSA conducted for six implementation sites in Tucson

was a set of suggestions to enhance the HAWK system with a view to its wider

(statewide or nationwide) application. Another outcome was a set of suggestions
ROAD SAFETY AUDITS: CASE STUDIES

16

for site-specific low-cost improvements that could be “piggybacked” onto the signal

implementation works to further enhance pedestrian and traffic safety.

5. The safety benefits of a project have been identified as part of the RSA process

and report.

In this RSA case studies project, all of the road improvement projects on which

RSAs were conducted during the planning or design stages were initially

motivated, wholly or in part, by a desire to address safety issues. Part of the RSA

process developed in this case studies project has been to identify safety issues

that were observed on-site or through collision data, and to clearly state how the

elements of the Design Team’s proposed improvements or design can be

expected to positively address these issues. Acknowledging the safety benefits of

the original design puts the RSA findings in an appropriate context.

6. RSA teams have been composed of a multidisciplinary group of experienced

professionals.

The core disciplines on an RSA team are traffic operations, geometric design, and

road safety. Beyond these core requirements, all of the RSA teams in this case

studies project have included members who have brought a range of backgrounds

and specialties to the RSA. For example, the RSA of a preliminary design for

arterial road upgrades for the Illinois DOT involved a team of professionals with

individual specialties in construction, maintenance, access management, and

enforcement. In addition, the RSA team included members from outside the state

as well as locally based members from Illinois DOT and FHWA Field Safety staff.

Those team members with local experience provided first-hand knowledge of local

policies, practices, and conditions (including important information on commuter

routes and local land use), while those from outside the state contributed ideas

gained from experience with other agencies and in other jurisdictions.

7. RSA reports have been brief.

The RSA report is concise, and focuses on describing safety issues and

suggested mitigation. Graphics and photographs were used as extensively as

possible. The reports included:

• background: a brief summary of the road or project being audited;
ROAD SAFETY AUDITS: CASE STUDIES

17

• RSA team and process: a listing of the RSA team members, the design or

as-built drawings used, site visit dates, and a description of the prioritization

method used;

• site observations made during site visits, including photographs;

• safety benefits of the proposed improvements, describing elements of the

project that are expected to effectively address existing safety issues or

otherwise enhance road safety;

• RSA findings: a listing of safety issues and suggested mitigation, usually

one or two pages each. A two-page example is shown in FIGURE 6. A

safety issue has been identified in a single sentence at the top of the page.

A description of the safety issue follows, describing the nature of the safety

concern and how it may contribute to collisions. A figure has been used to

illustrate the safety issue. Prioritization of the safety issue follows, using the

prioritization matrix described earlier, and ways to address the safety issue

are suggested.

FIGURE 6 EXAMPLE DISCUSSION OF AN RSA SAFETY ISSUE
ROAD SAFETY AUDITS: CASE STUDIES

18

Lessons Learned

Over the course of the RSA case studies project, the RSA teams have identified

several key elements that help to make an RSA successful.

1. The RSA team must acquire a clear understanding of the project background

and constraints.

At the RSA start-up meeting, a frank discussion of the constraints and challenges

encountered in the design of the project, or operation of existing road, is critical to

the success of the RSA. It is crucial that the RSA team understand the trade-offs

and compromises that were a part of the design process. Knowledge of these

constraints helps the RSA team to identify mitigation measures that are practical

and reasonable.

2. The RSA team and Design Team need to work in a cooperative fashion to

achieve a successful RSA result. It is important to maintain an atmosphere of

cooperation among all participants in the RSA process – the Design Team, RSA

team, and the Owner.

The RSA team should be consistently positive and constructive when dealing with

the Design Team. Many problems can be avoided if the RSA team maintains

effective communication with the Design Team during the RSA (including the

opportunities presented in the start-up and preliminary findings meetings) to

understand why roadway elements were designed as they were, and whether

mitigation measures identified by the RSA team are feasible and practical. This

consultation also gives the Design Team a “heads-up” regarding the issues

identified during the RSA, as well as some input into possible solutions, both of

which can reduce apprehension (and therefore defensiveness) concerning the

RSA findings.
ROAD SAFETY AUDITS: CASE STUDIES

19

The cooperation of the Design Team is vital to the success of the RSA. An RSA is

not a critical review of the design team’s work, but rather a supportive review of

the design with a focus on how safety can be further incorporated into it.

Cooperation between the RSA team and Design Team usually results in a

productive RSA, since the RSA team will fully understand the design issues and

challenges (as explained by the Design Team), and suggested mitigation

measures (as discussed in advance with the Design Team) will be practical and

reasonable.

Support from the Owner is vital to the success of individual RSAs and the RSA

program as a whole. It is essential that the Owner commit the necessary time

within the project schedule for conducting the RSA and incorporating any

improvements resulting from it, as well as the staff to represent the Owner in the

RSA process (primarily the start-up and preliminary findings meetings).

3. A “local champion” can greatly help to facilitate the establishment of RSAs.

Wilson and LipinskiF

2

F noted in their recent synthesis of RSA practices in the United

States (1) that the introduction of RSAs or an RSA program can face opposition

based on liability concerns, the anticipated costs of the RSA or of implementing

suggested changes, and commitment of staff resources. To help overcome this

resistance, a “local champion” who understands the purposes and procedures of

an RSA, and who is willing and able to promote RSAs on at least a trial basis, is

desirable. Thus, measures to introduce RSAs to a core of senior transportation

professionals can help to promote their wider acceptance. “Local champions”

have been found within state DOTs, FHWA field offices, or city, county, or Tribal

transportation agencies.

4. The RSA field review should be scheduled to coincide with important site

conditions.

The RSA team should visit the project site when traffic conditions are typical or

representative. For example, the RSA in Yellowstone National Park was

conducted at the start of the Park’s summer season when visitor volumes were

2 Eugene Wilson and Martin Lipinski. NCHRP Synthesis 336: Road Safety Audits, A Synthesis of

Highway Practice (National Cooperative Highway Research Program, TRB, 2004)
ROAD SAFETY AUDITS: CASE STUDIES

20

increasing. Consequently, the RSA team observed parking and circulation issues

that were characteristic of the Park’s high-volume summer season. In contrast,

the RSA in Cincinnati was conducted in late December, after classes at a nearby

university had ended. The RSA team was consequently unable to observe the

impact of university traffic at the site. Although this did not significantly affect the

RSA findings, scheduling the field review to observe typical or usual traffic

conditions is preferable, since it allows the RSA team to see how regularlyrecurring traffic conditions and road user behavior may affect safety.
ROAD SAFETY AUDITS: CASE STUDIES

21

CONCLUSION

The RSA case studies project sponsored by the FHWA Office of Safety has been

well received by the participating transportation agencies. The case studies

project has exposed State and local agencies and Tribal governments to the

concepts and practices of an RSA, and provided the opportunity for agency staff

members to participate on the RSA team as part of the process. Within a year of

the first case study RSA, at least two of the participating agencies have

implemented regular RSA programs for their new and upgrade transportation

projects.

This case study document has summarized the results of each RSA, with the

intent of providing State and local agencies and Tribal governments with examples

and advice to assist them in implementing RSAs in their own jurisdictions. In the

future, an evaluation of these RSAs, as well as other RSAs conducted in the

United States, will be conducted and published to provide further guidance to

agencies contemplating an RSA program in their jurisdictions.

ROAD SAFETY AUDITS: CASE STUDIES

A-1

APPENDIX A

RSA CASE STUDIES
ROAD SAFETY AUDITS: CASE STUDIES

A-2

RSA NUMBER 1

ILLINOIS DEPARTMENT OF TRANSPORTATION:

RSA OF IMPROVEMENTS TO CLEAR LAKE AVENUE AND DIRKSEN PARKWAY

Project: improvements to roadways and intersections in a commercial area adjacent to an interchange

Planned Improvements: access consolidation and construction of two new service roads

dual left turn lanes at existing intersection

realignment of local road

new signalized intersection

Project Environment: urban suburban rural

Project Design Stage: conceptual (0 to 30%) preliminary (40 to 80%) advanced (over 80%)

Project Cost: < $100,000 $100,000 - $1,000,000 >$1,000,000

Project Owner: Illinois Department of Transportation

Road Safety Audit

Date of RSA: 8-10 February 2005

RSA Stage(s): design stage RSA of existing roads

RSA team: staff from Federal Highway Administration Resource Center, Federal Highway

Administration Illinois Field Office, Illinois DOT, and Opus Hamilton

PROJECT BACKGROUND:

Clear Lake Avenue connects the I-72/I-55 interchange east of Springfield, Illinois, with downtown

Springfield. Dirksen Parkway intersects Clear Lake Avenue just west of the interchange. Views of

Clear Lake Avenue and Dirksen Parkway are shown in FIGURE A.1. In addition to functioning as

major arterials, both roadways provide access to adjacent commercial properties.

The intersection of Clear Lake Avenue and Dirksen Parkway was designated a high accident

location for six consecutive years (1998 through 2003), and the intersection of Hill Street and Clear

Lake Avenue was designated a high accident location in 2003. In response, the Illinois Department

of Transportation (IDOT) developed plans to upgrade Clear Lake Avenue between Dirksen

Parkway and the I-72/I-55 interchange. The scope of the planned improvements, shown in

FIGURE A.2, included:

access consolidation and construction of two new service roads intersecting Clear Lake

Avenue at a new signalized intersection east of Dirksen Parkway;

realignment of Hill Street (a local road) to intersect Clear Lake Avenue at new signalized

intersection;

dual left turn lanes on all legs of the intersection of Clear Lake Avenue and Dirksen

Parkway, and dual right turn lanes on the southeast corner of the intersection.
ROAD SAFETY AUDITS: CASE STUDIES

A-3

Clear Lake Avenue (looking west toward

intersection with Dirksen Parkway)

Dirksen Parkway (looking south toward

intersection with Clear Lake Avenue)

FIGURE A.1 VIEWS OF RSA SITE (ILLINOIS DOT RSA)

realigned Hill Street

new north service road

new south service road

additional left- and right-turn lanes

new signalized intersection

DIRKSEN PARKWAY

CLEAR LAKE AVENUE

FIGURE A.2 RSA PROJECT (ILLINOIS DOT RSA)

KEY RSA FINDINGS AND SUGGESTIONS:

The key findings and suggestions of the RSA are summarized in TABLE A.1.
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A-4

TABLE A.1 SUMMARY OF SELECTED SAFETY ISSUES AND SUGGESTIONS

ILLINOIS DOT RSA

SELECTED SAFETY ISSUE

(Number and Description)

RISK

RATING SUGGESTIONS

1

The new signalized Hill Street

intersection will be about 650 feet from

the signalized intersection of Dirksen

Parkway and Clear Lake Avenue.

C

coordination of adjacent signals

“Do Not Block Intersection” signs

signing and signal displays to enhance

intersection conspicuousness

2

The realigned Hill Street can be

expected to accommodate commercial

driveways, which may be located on

back-to-back horizontal curves.

C

raised medians to prohibit left turns

inclusion of service roads along Hill

Street

measures to regulate driveway design

and location

3

Queued, turning, and parking vehicles

around the closely-spaced intersections

at Clear Lake Ave. and the south service

road may interfere with each other.

D

restricted turning movements

relocation of service road intersection

relocation of specified parking stalls in

parking lot

confirmation of pavement strength

4

Drivers exiting the interchange onto

Clear Lake Avenue encounter a new

urban driving environment with slower

speeds and greater potential for conflicts

with stopping and turning vehicles.

--

“Gateway” treatment:

curb and gutter drainage

landscaping treatments

more conspicuous signing

visitor pull-out (if space permits)

5 Opportunities for interim improvements --

clearer signing for eastbound traffic

improved signing at raised medians

accommodation of high demand at Hill

Street intersection

review of permitted left turns

improved pedestrian facilities

interim access management

improved signal visibility (eastbound)

KEY LESSONS LEARNED:

The benefit of a design-stage RSA can be increased by including a review of existing roads, based

on the RSA team’s site visit, particularly where the design project will not be implemented for

several years. Typically, roadway improvements are motivated at least in part by an effort to

improve traffic safety. Consequently, traffic safety issues are frequently already a concern at the

RSA site. The RSA site visit provides an opportunity for a group of traffic and road safety experts

to examine the site with a view to identifying immediate, low-cost improvements that can be

implemented on an interim basis before the start of construction.

See also the discussion of “Key Factors for Success” and “Lessons Learned” in the main text.
ROAD SAFETY AUDITS: CASE STUDIES

A-5

RSA NUMBER 2

OKLAHAMA DEPARTMENT OF TRANSPORTATION:

RSA OF IMPROVEMENTS TO US HIGHWAY 60

Project: widening and resurfacing a two-lane rural highway

Planned Improvements: replacement of three bridges over two creeks

shoulder widening to provide a continuous 8-foot paved shoulder

intersection improvements (one intersection)

resurfacing of improved section as well as an adjacent 1.2-mile section

Project Environment: urban suburban rural

Project Design Stage: conceptual (0 to 30%) preliminary (40 to 80%) advanced (over 80%)

Project Cost: < $100,000 $100,000 - $1,000,000 >$1,000,000

Project Owner: Oklahoma Department of Transportation

Road Safety Audit

Date of RSA: 1-3 February 2005

RSA Stage(s): design stage RSA of existing roads

RSA team: staff from Federal Highway Administration Oklahoma Field Office, Oklahoma DOT,

and Opus Hamilton

PROJECT BACKGROUND:

US 60 is a US numbered highway (part of the National Highway System) extending for 350 miles

across northern Oklahoma. The RSA team reviewed detailed (90 percent) design stage drawings

of upgrades to a 2.9-mile stretch of US 60 in Osage County. Along the upgraded section, US 60

has a posted speed limit of 65 mph, and a reported AADT of 3,500 vehicles. The existing roadway,

shown in FIGURE A.3, is a two-lane rural roadway having 12-foot driving lanes with narrow or

absent paved shoulders. In addition to resurfacing, the upgrades included:

replacing existing bridges over Buck Creek and Turkey Creek, including reconstructing the

approach roadways as two 12-foot lanes with 8-foot paved shoulders;

between the bridges, widening shoulders to provide a continuous 8-foot paved shoulder

and adding one channelized right turn lane at the unsignalized intersection with Bowring

Road, a section-line road;

resurfacing a 1.2-mile “incidental section” west of Buck Creek (12-foot lanes with 2-foot

paved shoulders) to connect with an adjacent segment of US 60 further west that had been

recently overlaid.

The RSA team also reviewed proposed construction-stage detours.
ROAD SAFETY AUDITS: CASE STUDIES

Buck Creek bridge

(planned improvements include repaving, bridge

improvements, and 8’ paved shoulders)

adjacent “incidental” section

(planned improvements include repaving and 2’ paved

shoulders)

FIGURE A.3 VIEWS OF RSA SITE (OKLAHOMA DOT RSA)

KEY RSA FINDINGS AND SUGGESTIONS:

The key findings and suggestions of the RSA are summarized in TABLE A.2. The DOT responded

that changes would be made as suggested except for changes that would involve re-negotiation

with property owners or utility relocation (Issue 1), since these processes were already complete,

or changes that would entail substantial delay or additional expense (redesign of cross-section

elements on the incidental section, Issue 2D). The DOT also declined the suggestion to install

rumble strips, since they are not typically used on Oklahoma highways.

KEY LESSONS LEARNED:

It is important to identify the safety benefits of the design as part of the RSA process. The

improvements to US60 were motivated largely by safety, to provide a consistent and high-quality

roadway where the existing roadway was characterized by poor pavement and roadside conditions.

As part of the RSA process, the RSA team identified how the elements of the Design Team’s

proposed improvements were expected to positively address existing safety concerns. Examples

cited in the RSA report included the following:

Paved 8-foot shoulders and shallower fill slopes will reduce the risk and severity of off-road

collisions.

Resurfacing will improve the travel surface, and new pavement markings will improve

driver guidance.

Bridge reconstruction will increase the clearance distance to roadside safety issues, and

provide the opportunity to improve barrier end treatments.

Acknowledging the safety benefits of the original design put the RSA findings in an appropriate

context.

See also the discussion of “Key Factors for Success” and “Lessons Learned” in the main text.

A-6
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A-7

TABLE A.2 SUMMARY OF SELECTED SAFETY ISSUES AND SUGGESTIONS

OKLAHOMA DOT RSA

SELECTED SAFETY ISSUE

(Number and Description)

RISK

RATING SUGGESTIONS

1

Vertical crest curves limit drivers’

advance view of the intersection of

US60 with Bowring Road.

C

“Intersection Ahead” warning signs

relocate private driveways to minor

approach

provide acceleration lane

2 The safety impacts of improving the incidental section should be reviewed:

2A

The overlay may reduce the

effectiveness of an existing guardrail.

Reinstall guardrail at an appropriate

height.

2B The shoulder width will drop from 8

feet to 2 feet for westbound traffic.

Provide appropriate tapers at transition

point.

Provide appropriate delineation.

2C

Westbound drivers may fail to follow

the horizontal curve near the east end

of the incidental section.

Provide appropriate signs and

delineation.

2D

The improved overlay surface may

encourage higher prevailing speeds

along the incidental section, which

may be designed to an outdated

standard.

C

Confirm that existing design elements are

consistent with likely speeds and current

geometric standards.

Introduce edgeline and/or centerline

rumble strips.

3

Potential roadside safety issues may

be present during construction. C

Consider reduction in construction speed

limit.

Flare or protect ends of temporary

barrier.

Introduce temporary barrier near 2:1

slope.

4

A proposed guardrail ends at a private

driveway. B Wrap guardrail around driveway.
ROAD SAFETY AUDITS: CASE STUDIES

RSA NUMBER 3

OREGON DEPARTMENT OF TRANSPORTATION:

RSA OF IMPROVEMENTS TO US 97 (MODOC POINT TO SHADY PINE ROAD)

Project: improvements to two-lane rural highway in a constrained area

Planned Improvements: cold plane removal and overlay of the existing surface

widening of shoulders to 8 feet along some sections

elimination or protection of clear zone safety issues

new and upgraded barriers, guardrails, and end terminals

minor realignment to improve sight distances and to move the highway away from

some rock fall areas

construction of retaining walls

Project Environment: urban suburban rural

Project Design Stage: conceptual (0 to 30%) preliminary (40 to 80%) advanced (over 80%)

Project Cost: < $100,000 $100,000 - $1,000,000 >$1,000,000

Project Owner: Oregon Department of Transportation

Road Safety Audit

Date of RSA: 11-13 April 2006

RSA Stage(s): design stage RSA of existing roads

RSA team: staff from Federal Highway Administration (including Office of Safety, Resource Center,

and Oregon Field Office), Oregon DOT, VHB, and Opus Hamilton Consultants

PROJECT BACKGROUND:

A-8

The project, along US Highway 97 between

Modoc Point and Algoma, was located in

Klamath County in South Central Oregon.

In this area, the US 97 alignment passes

along the east side of Upper Klamath Lake

and the Union Pacific Railroad (FIGURE

A.4). The Oregon Department of

Transportation (ODOT) identified several

safety issues along this section of US 97,

including a fatality rate of 5.3 per million

vehicle miles, almost double the average

rate for similar Oregon highways. The DOT

noted the presence of narrow substandard

shoulders widths, substandard cut and fill slopes, and unprotected safety issues within clear the

zone, including barriers, guardrail, and guardrail end terminals that did not meet current standards.

FIGURE A.4 RSA SEGMENT OF US 97
ROAD SAFETY AUDITS: CASE STUDIES

A-9

To address these and other concerns, a two-phase road improvement program was adopted by

ODOT. Phase One work, which began in early 2005 and was in progress at the time of the RSA,

included replacement/repair of four bridges as well as rockfall work and widening on the east side

of the highway. Phase Two work, which was to be let in September 2007 with a projected

completion date of November 2009, was expected to take place on the west side of US 97,

between the highway and the adjacent railroad tracks.

The improvement projects were subject to several conditions that imposed unique and substantial

constraints on design and construction:

 Topography and slope stability were challenging constraints. Steep, unstable slopes were

present on both sides of the highway (FIGURE A.4). The project limits included six rockfall

sites, one of which would be affected by construction.

 To the west of the roadway, the Union Pacific Railroad imposed right-of-way constraints

that affected road design. In addition, the railroad’s rockfall warning system affected

construction methods.

 Cultural sites associated with the area’s Indian tribes affected slope stabilization efforts.

 The roadway, which was to remain open during construction, must accommodate mobility

needs. ODOT required that the construction design maintain specified minimum lane

widths and that average traffic delay not exceed six minutes. In addition, US 97 is a

designated truck corridor, and was expected to accommodate additional truck traffic

diverted from nearby construction works on Interstate Highway 5.

This RSA incorporated the use of the Interactive Highway Safety Design Model (IHSDM), a suite of

software analysis toolsF

3

F being developed by the FHWA to provide an explicit, quantitative

evaluation of safety and operational effects of geometric design on two-lane rural highways.

IHSDM was used to evaluate the elements of the existing and proposed design against design

policy values, design consistency, and to predict the expected safety of the future road. IHSDM

may be downloaded free of charge at http://www.ihsdm.org.

KEY RSA FINDINGS AND SUGGESTIONS:

The key findings and suggestions of the RSA are summarized in TABLE A.3.

3

IHSDM currently includes five evaluation modules: Crash Prediction Module (CPM), Design Consistency Module (DCM),

Intersection Review Module (IRM), Policy Review Module (PRM), and Traffic Analysis Module (TAM).
ROAD SAFETY AUDITS: CASE STUDIES

A-10

TABLE A.3 SUMMARY OF RSA SAFETY ISSUES AND SUGGESTIONS

OREGON DOT RSA

SAFETY ISSUE

(Number and Description)

Risk

Rating Suggestions

1

Roadside safety issues included:

 steep slopes and ditches within

clear zone

 unprotected utility poles

 shoulder edge-drops.

D

additional roadside barriers

relocation or shielding of utility poles

fillet to limit edge-drops

2

Sight distance was constrained by

roadside topography, rockfall fences, and

bridge superstructures at horizontal

curves and at intersections.

C

confirm stopping sight distance

review of specified sight distance

obstructions at intersections

3

Limited night-time guidance was provided

on a curved alignment with hazardous side

slopes. An enhanced level of delineation

would be beneficial along this hazardous

segment of roadway.

B

enhanced post-mounted delineators

improved centerline and edgeline

delineation

4

Signing issues included possible re-use of

faded signs, missing intersection warning

signs, and use of small lettering on street

name signs.

B

intersection warning signs

advance street name signs and larger

street name signs

confirm retroreflectivity of reused

signs

5

Rockfall protection formed an important

part of the design requirements. The

very challenging improvement site may

be a candidate for the use of enhanced

rockfall protection measures.

B

enhanced rockfall protection

measures if standard measures are

ineffective or infeasible

6

High speeds contributed to increased

collision risk and severity. C

use of IHSDM in speed enforcement

variable speed limits

7

Winter weather: A high proportion of

crashes occurred under winter road

conditions.

C ice detection and warning system
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A-11

KEY LESSONS LEARNED:

The Interactive Highway Safety Design Model (IHSDM) is a useful tool to quantify safety issues

associated with the audited design.

This RSA used IHSDM to evaluate design consistency, compliance with selected design policy

values, and to predict the expected safety of the future roadway. Specifically,

the proposed alignment was analyzed using:

the IHSDM Policy Review Module (PRM) to identify two locations where stopping sight

distance did not appear to meet minimum sight distance requirements. It is important to

note that an RSA is not simply a check that design standards have been met. Therefore,

minimum policy checks using IHSDM were limited to sight distance policy checks. This

enabled the RSA team to observe conditions in the field that IHSDM identified as having a

sight distance issue.

the IHSDM Crash Prediction Module (CPM) and five years of crash data (2000-2004) to

identify the potential for a future increase in crash frequency at two intersections along the

alignment;

the IHSDM Design Consistency Module (DCM) to estimate free flow 85th percentile

operating speeds between successive alignment elements, as a measure of design

consistency. The results from the DCM suggested that, with the proposed improvements,

the alignment of US 97 was reasonably consistent. The DCM found no locations requiring

speed reductions greater than 6 mi/hr entering a curve, which was considered the upper

limit for good consistency. There were however, two horizontal curves where the DCM

module identified speed differentials approaching this limit, and the PRM module identified

insufficient stopping sight distances. The RSA team flagged the locations where the

combination of design-consistency and sight-distance issues was found for the Design

Team's further consideration.

The ability to quantify values associated with design issues such as stopping sight distance, and to

estimate future crash frequencies based on the road re-design, enhanced the value of the RSA by

demonstrating the magnitude of the safety issues identified by the RSA team. Without IHSDM

estimates, the RSA team could identify, but could not necessarily quantify, expected changes in

safety parameters such as operating speeds or in expected crash frequencies. Quantifying these

parameters and frequencies provided a higher level of confidence to all parties (the RSA team,

Design Team, and Owner) concerning the magnitude and importance of the safety issues identified

in the RSA.

See also the discussion of “Key Factors for Success” and “Lessons Learned” in the main text.
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A-12

RSA NUMBER 4

WISCONSIN DEPARTMENT OF TRANSPORTATION:

RSA OF IMPROVEMENTS TO MARQUETTE INTERCHANGE

Project: reconstruction of a major interstate interchange in Milwaukee, Wisconsin

Planned Improvements: replacement of three bridges over two creeks

shoulder widening to provide a continuous 8-foot paved shoulder

intersection improvements (one intersection)

resurfacing of improved section as well as an adjacent 1.2-mile section

Project Environment: urban suburban rural

Project Design Stage: conceptual (0 to 30%) preliminary (40 to 80%) advanced (over 80%)

Project Cost: < $100,000 $100,000 - $1,000,000 >$1,000,000

Project Owner: Wisconsin Department of Transportation

Road Safety Audit

Date of RSA: 1-3 February 2005

RSA Stage(s): design stage RSA of existing roads

RSA team: staff from Wisconsin DOT, Milwaukee County Sheriff’s Office, Federal Highway

Administration, and Opus Hamilton

PROJECT BACKGROUND:

Highways I-94, I-794, and I-43 meet at the Marquette Interchange in Milwaukee. The interchange,

considered the cornerstone of the southeastern Wisconsin freeway system, accommodates

Milwaukee’s commuter traffic, as well as interurban traffic traveling to and from Madison, Green

Bay, and Chicago, and long-distance interstate traffic. Reconstruction of the existing interchange,

which built in 1968, was required to address structural deterioration and operational concerns. At

the time of the RSA in December 2003, planning and design for the reconstructed interchange had

been ongoing for several years, and construction was to commence in about six months. The RSA

examined both the proposed changes and construction-stage plans, since the interchange was

required to remain operational throughout the four-year construction period. The existing and

redesigned interchanges are shown in FIGURE A.5. The total cost of the interchange

reconstruction was anticipated to be $800 million.
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A-13

Existing Interchange Improved Interchange (simulation)

FIGURE A.5 EXISTING INTERCHANGE AND PROPOSED IMPROVEMENTS

The planned reconstruction includes upgrades and improvements include:

replacement of left-side ramps with conventional right-side ramps,

lengthening or elimination of existing short weaving sections,

increased curve radii on ramps,

lane continuity and consistency for through traffic,

increased capacity on system ramps,

increased barrier height.

KEY RSA FINDINGS AND SUGGESTIONS:

The key findings and suggestions of the RSA are summarized in TABLE A.4. In their response,

the design team accepted a number of suggestions that could be implemented at the late design

stage for this RSA, but declined suggestions that would entail revisiting the public involvement,

design, or environmental assessment processes. A number of suggestions were identified as

already in the design plans (see discussion below on document control under “Lessons Learned”).

Where signing could be retroactively deployed to correct a safety issue (Issue 2), the design team

suggested monitoring operations after improvements were completed to confirm whether the safety

issue would actually occur before implementing suggested signing changes.
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A-14

TABLE A.4 SUMMARY OF SELECTED SAFETY ISSUES AND SUGGESTIONS

WISCONSIN DOT RSA

SELECTED SAFETY ISSUE

(Number and Description)

RISK

RATING SUGGESTIONS

1

Plankinton Exit Ramp and Clybourn

Street Entry Ramp: Mainline drivers

may attempt an abrupt, unsafe lane

change to access these ramps.

D

Extend a proposed concrete barrier to

block unsafe movements.

2

Westbound I-94: Traffic from two highvolume system ramps meets the eastwest mainline approximately about

1,700 feet upstream of Exit 309B,

resulting in a limited weave distance.

E

Provide advanced signing for Exit 309B

to reduce the need for sudden lane

changes.

Block access to Exit 309B from

westbound I-94.

3A

Wisconsin Avenue at 11th Street: Dual

turning lanes leading to different

destinations may cause driver

confusion and erratic movements.

C

Improve signing and pavement marking.

Consider geometric changes (possibly

as a future retrofit).

3B

Highland Street: During peak periods,

left-turn queues may extend into or

past adjacent closely-spaced

intersections on Highland Street.

D

Conduct microsimulation modeling.

Signalize / coordinate ramp intersection.

Restrict some left-turn movements.

3C

Highland Street at 12th: Long crossing

distances, diagonal curb ramps, and a

partial crosswalk obstruction may

increase the pedestrian collision risk.

D

Review / improve accommodation of

pedestrians.

4

Barrier Heights at Ramps: The

proposed barrier height of 42 inches

on system-to-system ramps may not

be sufficient to prevent truck roll-over

collisions.

C

Consider higher barriers where needed

and where feasible.

5

Signing: Some proposed signing may

not provide sufficient guidance,

especially to unfamiliar drivers.

B

Clarify “Downtown” signing.

Clarify cardinal directions.

Add advance signing at noted locations.

Add ramp advisory speed limit signs.

6A

Distractions During Construction:

Roadside construction activities may

distract or startle drivers,

C

Consider “gawk screens” to block

drivers’ view of construction activities.

6B

Construction Phase Traffic

Management: Construction-phase

routing may entail some risk for

drivers.

D

Conduct microsimulation analysis, and

consider specified road closures or

turning restrictions to reduce traffic load

on unsuitable local streets.
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KEY LESSONS LEARNED:

RSAs conducted late in the design process require a selective focus to be effective. The

Marquette Interchange RSA was conducted at an advanced stage in the interchange design, after

the completion of the public involvement process, and was consequently limited in the range of

items and suggested alternatives that could usefully and practically be identified and implemented.

Fundamental design elements had to be taken as “given”, since changes to them were impractical

at the advanced stage that the RSA was conducted. Consequently, the RSA team focused on

elements of the design that could be amended or mitigated at the detailed design stage.

Time constraints require that the RSA team direct its efforts and use its time efficiently. As is

typical for design-stage RSAs, this RSA was on the critical path in the Interchange design

schedule. The RSA team had less than five days to review a comprehensive interchange design

that had been many years in the making. The RSA was therefore limited in its level of detail.

Consequently, the RSA team split into two- or three-person teams to cover the interchange

elements as comprehensively as possible. The RSA team presented its preliminary findings to the

Owner and Design Team after the RSA analysis session, and followed up with the RSA report.

The design team issued a timely response to the RSA, outlining what actions had or would be

taken. The entire RSA process was completed within three months.

Document control is an important element of the RSA process to ensure that the RSA is based on

the most recent design drawings. As with all very large design projects, the Marquette Interchange

design generated a vast number of drawings and other documents. The RSA team based its

review on drawings which, in some cases, had been superseded at the time of the RSA. The

inadvertent inclusion of superseded drawings in the RSA materials reflected the large volume of

design documentation on this very large project that was in its final design stages, and the resulting

document control issues.

Specialists contribute valuable insight on the RSA team. Members of the eight-person RSA team

had a general knowledge of road safety, geometric design, and traffic operations, but several

members also had specialized knowledge in various areas. The RSA team included an officer from

the Milwaukee County Sheriff’s Office who had extensive experience as a patrol officer on the

existing interchange. The insights offered by the officer regarding driver behavior helped the

design team to realistically assess the risk associated with design elements and the effectiveness

of suggested improvements.
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The success of the RSA was promoted by early management of expectations, and by a

cooperative approach on the part of all participants. At the start of the RSA, the RSA team

explained to the Design Team and Owner what could feasibly be audited within the constraints of

the time available and the advanced design stage. At the same time, the Design Team outlined its

constraints in terms of the trade-offs that were a necessary part of the design process. This

exchange promoted an understanding on the part of all participants concerning what could feasibly

be achieved in the RSA. Prior to the start of the RSA, the Design Team responded to the RSA

team’s request to identify design issues that they felt the RSA team could assist with. The Design

Team identified twelve issues, such as complex intersection channelization and the need to

obstruct improper or prohibited vehicle movements (such as wrong-way movements onto exit

ramps). The RSA was conducted in the Design Team office, and the Design Team made available

a senior designer to answer the RSA team’s questions and clarify issues. This continual liaison

enabled the RSA to be completed in the limited time available.

See also the discussion of “Key Factors for Success” and “Lessons Learned” in the main text.
ROAD SAFETY AUDITS: CASE STUDIES

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RSA NUMBER 5

CLARK COUNTY (WASHINGTON):

RSA OF IMPROVEMENTS TO UPPER WARD ROAD

Project: road alignment and intersection improvements to two-lane rural road

Planned Improvements: realignment of horizontal curves

reconfiguration of four intersections, including traffic control changes

Project Environment: urban suburban rural

Project Design Stage: conceptual (0 to 30%) preliminary (40 to 80%) advanced (over 80%)

Project Cost: < $100,000 $100,000 - $1,000,000 >$1,000,000

Project Owner: Clark County, Washington

Road Safety Audit

Date of RSA: 10-12 May 2005

RSA Stage(s): design stage RSA of existing roads

RSA team: staff from Clark County and Opus Hamilton

PROJECT BACKGROUND:

The improvements to Ward Road, a two-lane rural roadway, were initially motivated by safety

concerns resulting from high-severity off-road collisions. Subsequently, the county’s Growth

Management Act (1995) resulted in anticipated changes to the road network and hierarchy in the

vicinity of the planned improvements, which resulted in the introduction of additional elements to

the upgrades. The road improvements were the subject of considerable public interest and input,

which have also influenced their design.

The planned improvements affected three roads: Ward Road (also known as 182nd Avenue), 172nd

Avenue, and 119th Street, shown in FIGURE A.6. In addition to functioning as major rural

collectors, these roads provided access to adjacent properties (residential and farm) and a small

farming town. Improvements, numbered and shown in FIGURE A.7, included:

1) realignment of Ward Road between 172nd Avenue and Davis Road (involving

abandonment of an existing road section on structure), and introduction of a new fourway signalized intersection;

2 and 3) intersection improvements at the STOP-controlled intersections of 119th Street / 172nd

Avenue and 119th Street / 182nd Avenue, including the introduction of a free right turn

lane on one approach;

4) reconfiguration of the existing Ward Road / Davis Road intersection, and relocating the

STOP sign from Davis Road to 182nd Street.
ROAD SAFETY AUDITS: CASE STUDIES

Ward Road near Davis Road 172nd Avenue near Ward Road 182nd Avenue at 119th Street

FIGURE A.6 VIEWS OF RSA SITE (CLARK COUNTY RSA)

SOURCE: Wallis Engineering

FIGURE A.7 RSA PROJECT (CLARK COUNTY RSA)

A-18
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At the time of the RSA, the improvements were in the county’s current Transportation Improvement

Program, and were in the final design stage. Overall construction costs were estimated at about $9

million, including land acquisition costs.

KEY RSA FINDINGS AND SUGGESTIONS:

The key findings and suggestions of the RSA are summarized in TABLE A.5.

TABLE A.5 SUMMARY OF SELECTED SAFETY ISSUES AND SUGGESTIONS

CLARK COUNTY RSA

SELECTED SAFETY ISSUE

(Number and Description)

RISK

RATING SUGGESTIONS

1

New Conflict Points: Traffic on Ward

Road will be directed through

reconfigured intersections where new

traffic control devices and required

turn maneuvers will generate an

increased potential for rear-end,

turning, and merging conflicts.

C

Provide turning lanes.

Revise turning radius at free right turns to

better accommodate pedestrian safety.

Install YIELD control at free right turns.

Review safety of right-turn-on-red.

Provide delineation in merge areas.

Review pedestrian and bicycle requirements.

2

Free Right Turn Lanes: Driver

workload may be high at free right turn

lanes.

B

Confirm that guardrail does not restrict sight

distances.

Revise turning radius to better accommodate

pedestrian safety.

Install YIELD control.

Review safety of right-on-red.

Provide delineation in merge area.

3

Limited Clear Zones: Limited clear

zones increase the risk and potential

severity of collisions when drivers

leave the travel lanes.

C

Remove fixed objects within the clear zone.

Provide barriers at marginally critical slopes if

the slope steepness cannot be reduced.

4

Limited Sight Distances: Limited sight

distance may increase the risk of

collision when drivers fail to observe

potentially hazardous conditions

ahead.

C

Review alignment where a crest vertical

curve restricts drivers’ view of conditions

ahead. If alignment cannot be altered,

provide warning signs and delineation.

Confirm that guardrail does not restrict sight

distances at free right turn lanes.

5

Signing and Pavement Markings:

Proposed signing and pavement

markings may not be adequate.

--

Improve signing and pavement markings for:

dedicated turn lanes

unexpected conditions where horizontal and

vertical curves limit sightlines

right turn channelizing island at 182nd Avenue

and 119th Street.

6

Future Conditions on 172nd Avenue:

Proposed new land use may increase

vehicle, pedestrian, and bicycle traffic

on the improved roads.

B

Review pedestrian and bicycle requirements.

Prohibit street parking near proposed park.
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SELECTED SAFETY ISSUE

(Number and Description)

RISK

RATING SUGGESTIONS

7

Opportunities for Interim

Improvements --

Introduce left turn lane at existing intersection

of Ward Road/172nd Avenue.

Paint stop bar at existing intersection of Ward

Rd/172nd Ave.

Remove vegetation to improve sight triangle

if proposed change to 2-way STOP control at

119th St. and 182nd Ave is implemented.

KEY LESSONS LEARNED:

Even at a final design stage, the RSA team may need to identify significant safety issues

associated with fundamental design elements. Discussions with County staff indicated that,

although improvements to Ward Road were initially proposed primarily to address high-severity offroad collisions, additional issues arose during the lengthy public consultation process concerning

the level of traffic considered by different community groups to be suitable on the improved roads.

To reconcile the competing desires of these groups, and to provide a forum for the groups to

contribute beyond the public consultation stage to the actual design, a Community Design Team

(CDT) was established that included representatives of the adjacent communities. The design that

was adopted to meet the requirements of the CDT appeared to have expanded beyond the initial

safety-related aim of reducing collisions, to include two additional (and potentially competing) aims

of controlling traffic speeds by increasing the number of controlled intersections through which

traffic would pass, and achieving a redistribution of traffic that the CDT deemed equitable.

Although the County’s efforts to include the public in the design process were in many ways

laudable, the resulting reconfiguration of intersections and introduction of new traffic control

devices were expected to compromise traffic safety by introducing additional conflict points (see

Issues 1 and 2 in TABLE A.5). The RSA team felt it necessary to point out that that net result of

directing formerly free-flowing traffic through controlled intersections was expected to be decreased

severity, but increased frequency, of collisions compared with existing conditions. As a result of

the RSA, County engineering staff started a re-examination of major elements of the project, which

they expected would lead to a safer project at considerably less expense.

RSAs can contribute to achieving pre-existing roadway safety goals. This FHWA-sponsored RSA

contributed to the achievement of the Washington Traffic Safety Commission’s Target Zero: A

Strategic Plan for Highway Safety 2000, a statewide traffic safety plan supporting the achievement

of a transportation system without deaths or disabling injuries. Specifically, one of the Target Zero

emphasis areas was the road environment. Strategies in this area that the RSA supported

included improving signing and delineation, and training county traffic engineers and planners to

identify traffic safety problems and develop solutions. As a pilot implementation of a potential

state-wide program of RSAs, it may also have helped to promote the Target Zero strategy to

develop programs and partnerships to implement safety projects for local roadways.

See also the discussion of “Key Factors for Success” and “Lessons Learned” in the main text.
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RSA NUMBER 6

COLLIER COUNTY (FLORIDA):

RSA OF IMPROVEMENTS TO IMMOKALEE ROAD

Project: widening of four-lane arterial road

Planned Improvement: widening of arterial roadway from four lanes to six lanes

Project Environment: urban suburban rural

Project Design Stage: conceptual (0 to 30%) preliminary (40 to 80%) advanced (over 80%)

Project Cost: < $100,000 $100,000 - $1,000,000 >$1,000,000

Project Owner: Collier County, Florida

Road Safety Audit

Date of RSA: 15-19 November 2004

RSA Stage(s): design stage RSA of existing roads

RSA team: staff from Collier County, Federal Highway Administration Resource Center, VHB, and

Opus Hamilton

PROJECT BACKGROUND:

Immokalee Road, a County road, is a major east/west arterial connecting residential areas in

western Collier County with I-75, US Highway 41, and the City of Naples. The RSA section of the

roadway, shown in FIGURE A.8, was widened from two lanes to four lanes in 2002. The four-lane

cross-section, shown in FIGURE A.9, was a divided arterial roadway with two through lanes in

each direction, a grass median (up to about 40 feet wide), and turning lanes at signalized

intersections. The corridor was adjacent to low-density residential, commercial, and institutional

land uses, including the North Naples Fire Station No. 42, Gulf Coast High School, Laurel Oaks

Elementary School, and several churches.

To accommodate current and forecast future demand, the County was considering additional

widening to six lanes. The proposed upgrade would entail widening the road to a six-lane divided

urban arterial standard. At the time of the RSA, the widening project was at a conceptual stage.

Design documentation consisted of State design practices and the County’s typical section for a

six-lane divided urban arterial.
ROAD SAFETY AUDITS: CASE STUDIES

Collier Blvd

High SchoolEast Access

Laurel OaksElementary Rd

Valewood Dr

Northbrooke DrOakes Blvd

Signalized intersections shown.

FIGURE A.8 RSA SEGMENT (COLLIER COUNTY RSA)

Immokalee Road near Valewood Drive Immokalee Road in front of schools

FIGURE A.9 VIEWS OF RSA SITE (COLLIER COUNTY RSA)

KEY RSA FINDINGS AND SUGGESTIONS:

1BThe RSA findings were divided into two parts:

issues arising from the proposed upgrade (TABLE A.6): These issues reflected concerns

arising from the proposed upgrading from a four-lane mixed urban/rural arterial to a sixlane urban arterial cross-section, and dealt with properties or specific conditions of the

Immokalee Road widening project that could influence design details or require the

modification of design standards.

further opportunities for improvement (TABLE A.7): Additional opportunities for

improvements that could be incorporated in the upgrading works were also identified.

Although these improvements were not specifically related to the proposed widening, they

responded to issues observed along the corridor by the RSA team. These improvements

could be “piggybacked” onto the upgrade project at relatively limited effort and expense.

A-22
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A-23

TABLE A.6 SUMMARY OF SELECTED SAFETY ISSUES AND SUGGESTIONS

COLLIER COUNTY RSA

SELECTED SAFETY ISSUE

(Number and Description)

RISK

RATING SUGGESTIONS

1

accesses off arterial road: Movements

at driveways and local road

intersections interfere with traffic on

Immokalee Road, an arterial road.

D

Consult County’s access management

manual.

Consider closure of some median

breaks.

Introduce right-turn acceleration lanes.

Introduce devices and designs to prevent

wrong-way movements.

2

school-related pedestrian and vehicle

traffic: Increased volumes, lanes, and

width may increase the collision risk

for vehicle and pedestrian traffic

associated with adjacent schools.

C

Revise flashing signal operation at

adjacent intersections.

Consider median treatment to obstruct

midblock crossings.

Implement a continuous pedestrian

network.

Reduce curb return radii at adjacent

intersections.

3

pedestrian facilities: Pedestrians need

to be safely accommodated on the

upgraded roadway.

C

Provide a continuous and convenient

pedestrian network.

Provide pedestrian countdown signal

heads.

Reduce return radii at intersections and

driveways.

4

cycling facilities: Cyclists need to be

safely accommodated on the

upgraded roadway.

C

Replace 4-foot bike lanes with wider

paved shoulder.

Provide sufficient bike lane width at

intersections.

5

barriers with curb: The design of

roadside barriers must accommodate

the proposed barrier curb.

C

Consider anticipated speeds when

designing barrier system.

6

stakeholder consultation: Widening

Immokalee Road may affect the North

Naples fire station and may generate

an increased need for speed

enforcement.

--

Consult fire station to determine the need

for a fire signal.

Consult with police to identify their

enforcement requirements.
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TABLE A.7 SUMMARY OF OPPORTUNITIES FOR IMPROVEMENT:

COLLIER COUNTY RSA

SAFETY ISSUE

(Number and Description) SUGGESTIONS

1

median treatments: The impact of

median treatments on road safety

should be considered in this urbanized

transition area.

Avoid fixed-object safety issues in the median.

Avoid sight-line obstructions in the median.

Consider median treatments that obstruct midblock

crossings.

Minimize median maintenance requirements.

Consider angled left turn lanes in wide medians.

2

road shoulders: Shoulders may be

desirable for emergency use, especially

where fire-station traffic is expected.

Confirm whether shoulders are desirable for fire

department and other emergency use.

3

signal display: Signal displays should be

visible and conspicuous at all times.

Mount overhead signals on mast arms.

Consider redundant signal displays and/or double red

display for left-turn signals.

Consider one signal head for each lane.

Use a backplate with reflective border.

4

accommodation of older and unfamiliar

drivers: Older and unfamiliar drivers

require enhanced signing, pavement

marking, and signal displays.

Follow recommended practices of the Florida DOT

Elder Road User program.

KEY LESSONS LEARNED:

In very early-stage design RSAs, a wider scope for safety enhancements exists. This RSA was

conducted very early in the planning stage, when the only design documentation was the County’s

typical section for a six-lane divided urban roadway. As a result, the RSA was able to consider not

only issues related specifically to the proposed widening from four to six lanes (TABLE A.6), but

could also suggest additional opportunities, not necessarily related to the specified widening, to

enhance road safety (TABLE A.7). Of particular significance was the opportunity to include in the

roadway upgrades several measures to accommodate older drivers, which will help to County to

implement elements of the Florida DOT’s “Elder Road User Program” on County roads.

See also the discussion of “Key Factors for Success” and “Lessons Learned” in the main text.
ROAD SAFETY AUDITS: CASE STUDIES

A-25

RSA NUMBER 7

CITY OF CINCINNATI (OHIO):

RSA OF IMPROVEMENTS TO THE SPRING GROVE AVENUE CORRIDOR

Project: improvements to commuter arterial, including bridge widening and intersection improvements

Planned Improvements: intersection improvements

road and bridge widening

traffic signal improvements

Project Environment: urban suburban rural

Project Design Stage: conceptual (0 to 30%) preliminary (40 to 80%) advanced (over 80%)

Project Cost: < $100,000 $100,000 - $1,000,000 >$1,000,000

Project Owner: City of Cincinnati

Road Safety Audit

Date of RSA: 14-16 December 2004

RSA Stage(s): design stage RSA of existing roads

RSA team: staff from Federal Highway Administration, City of Cincinnati, VHB, and Opus

Hamilton

PROJECT BACKGROUND:

The City of Cincinnati was considering improvements along the Spring Grove Avenue corridor

between Winton Road and Clifton Avenue (FIGURES A.10 and A.11). Spring Grove Avenue and

Winton Road are major commuter arterials connecting areas to the north, east, and west to I-75.

Clifton Avenue is a two-lane major/minor arterial street connecting Spring Grove Road to the Clifton

area to the south, and providing access to commercial developments constructed in the past five

years on Kenard Avenue, a collector road.

The corridor had recently experienced a high number of crashes, putting the intersection of Spring

Grove Avenue and Winton Road at the top of the City’s High Accident Location list, and resulting in

an above-average collision rate at the intersection of Spring Grove Avenue and Clifton Avenue. In

addition, traffic near the intersection of Clifton Avenue and Kenard Avenue had increased to a point

where widening Clifton Avenue at the intersection (which would involve bridge widening south of

the intersection) was being considered.

This planning-stage RSA reviewed several upgrades, including:

Clifton Avenue bridge widening to accommodate four 10-foot lanes and a 10-foot painted

median strip,

traffic signal improvements at the intersection of Spring Grove Avenue and West Mitchell

Avenue,
ROAD SAFETY AUDITS: CASE STUDIES

other possible improvements to Spring Grove Avenue in connection with the planned

upgrade.

FIGURE A.10 RSA SITE (CITY OF CINCINNATI)

Spring Grove Avenue intersection of Winton Road and Spring Grove Avenue

FIGURE A.11 VIEWS OF RSA SITE (CINCINNATI RSA)

A-26
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A-27

KEY RSA FINDINGS AND SUGGESTIONS:

The key findings and suggestions of the RSA are summarized in TABLE A.8.

TABLE A.8 SUMMARY OF SELECTED SAFETY ISSUES AND SUGGESTIONS

CINCINNATI RSA

SELECTED SAFETY ISSUE

(Number and Description)

RISK

RATING SUGGESTIONS

1

traffic signal infrastructure:

Signal displays should be

visible and conspicuous at all

times.

D

Align traffic signal heads with approach

lanes.

Use redundant signal displays.

Upgrade all signal lenses to 12”.

Provide advance warning signs for signals

that follow horizontal curves.

Use backplates with reflective border.

2

turn-movement operations

and geometry: Conflicting

turning movements and

complex geometry increase

the risk of collisions at

intersections.

D

Review the need for dual turns.

Review concurrent dual turns.

Review the practice of providing protected

turn phasing in shared-use lanes.

Investigate opportunities for increasing turn

radii.

3

driveways and access

management: Movements at

driveways interfere with

traffic on arterial roads and

intersections, creating

potentially hazardous

conflicts.

C

Investigate opportunities to close and

consolidate some driveways.

Consider eliminating left turns into and out

of driveways.

Include driveway on the west leg of Clifton

Avenue / Kenard Avenue in the intersection

signalization.

4

road cross section: The cross

section of Spring Grove

Avenue includes apparent

inconsistencies.

B

Design the new cross-section with uniform

lane widths.

5

pedestrian facilities:

Pedestrian facilities need

upgrading and maintenance.

C

Provide consistent levels of lighting and

upgrade lighting at crosswalks.

Review warrant for upgrading crosswalk

makings near Station Avenue.

Improve sidewalk conditions.
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KEY LESSONS LEARNED:

The RSA field review should be scheduled to coincide with important site conditions. This RSA

was conducted in late December, after classes at a nearby university had ended. The RSA team

was consequently unable to observe the impact of university traffic at the site. Although this did not

significantly affect the RSA findings, scheduling the field review to observe typical or usual traffic

conditions is preferable, since it allows the RSA team to see how regularly-recurring traffic

conditions and road user behavior may affect safety.

See also the discussion of “Key Factors for Success” and “Lessons Learned” in the main text.
ROAD SAFETY AUDITS: CASE STUDIES

A-29

RSA NUMBER 8

CITY OF TUCSON (ARIZONA):

RSA OF PEDESTRIAN CROSSING IMPROVEMENTS

Project: installation of six new HAWK signalized pedestrian crossings

Planned Improvement: installation of HAWK signals at six existing pedestrian crosswalks

Project Environment: urban suburban rural

Project Design Stage: conceptual (0 to 30%) preliminary (40 - 80%) advanced (over 80%)

Project Cost: < $100,000 per crossing $100,000 - $1,000,000 >$1,000,000

Project Owner: City of Tucson

Road Safety Audit

Date of RSA: 26 - 28 October 2004

RSA Stage(s): design stage RSA of existing roads

RSA team: staff from Federal Highway Administration Resource Center, Arizona DOT, and Opus

Hamilton

PROJECT BACKGROUND:

HAWK (High-Intensity Activated

CrossWalK) signals are a type of

traffic control beacon for marked

pedestrian crosswalks, developed

by the City of Tucson and

implemented in Tucson and

elsewhere in Arizona. The City of

Tucson received approval from

FHWA to experiment with this

device; it is not yet adopted in the

Manual of Uniform Traffic Control

Devices. The innovative HAWK

signal, shown in FIGURE A.12,

incorporates elements from fire

station signals and school bus

flashing displays, as well as from

European pedestrian signal

displays, to provide a familiar signal

sequence for drivers and

pedestrians. The HAWK signal is

activated by a pedestrian

Source: City of Tucson

FIGURE A.12 HAWK PEDESTRIAN SIGNAL
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A-30

pushbutton. The activated signal progresses from a dark display through flashing amber, solid

amber, solid red, and flashing red, ending with a dark display. Drivers are required to stop during

the solid red display, and may proceed with caution during the flashing red display. Pedestrians

are controlled using traditional pedestrian signal displays and, at the sites audited under this

contract, countdown timers.

At the time of the RSA, about 40 HAWK signals were operating in Tucson, and the City was

expanding its HAWK installation program. In 2003, the City’s Mayor and Council allocated

increased funding to install HAWK signals at six additional locations throughout the City.F

4

F The six

sites selected for HAWK implementation were chosen on the basis of pedestrian and bicycle

collision frequency from 1999 through 2002. The six sites, listed in TABLE A.9, were the focus of

this RSA.

TABLE A.9 TUCSON RSA SITES

MAJOR ROAD MINOR ROAD 2004 MAJOR ROAD AADT*

Flowing Wells Road Pastime Road 24,900

First Avenue Graybill Drive 39,000

Broadway Boulevard Cherry Avenue 26,700

Fort Lowell Road Park Avenue 21,800

Speedway Boulevard Rook Avenue 47,600

Grant Road Palo Verde Boulevard 62,300

* Annual Average Daily Traffic volumes reported by the Pima Association of Governments

At the time of the RSA, the contract for construction had been awarded, and the underground

portion of construction was underway or had been completed at many of the sites. Final design

drawings for the signal hardware were complete. This RSA of locations where an experimental

pedestrian signal system was being implemented provided an opportunity to conduct an RSA with

a focus on pedestrian needs.

KEY RSA FINDINGS AND SUGGESTIONS:

The RSA findings were divided into two categories:

general HAWK system issues and suggestions (Issues 1 and 2),

site-specific issues and suggestions (Issues 3 to 6).

Observations regarding the general HAWK system (Issues 1 and 2) include suggestions that are

intended to enhance the HAWK system with a view to national adoption as a useful and effective

traffic control device with an intermediate level of control between a traditional flashing amber

beacon and a full signal.

4

Additional funding for further HAWK signals was approved by the City during the RSA.
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In its response, the City undertook to consider the RSA team’s suggestions and to monitor a

number of locations at which safety issues had been identified. For this late-stage RSA,

suggestions were declined where they would entail substantial changes to completed works, such

as changes to signal equipment or completed electrical works.

TABLE A.10 SUMMARY OF SELECTED SAFETY ISSUES AND SUGGESTIONS

TUCSON RSA

SELECTED SAFETY ISSUE

(Number and Description)

RISK

RATING SUGGESTIONS

1

use of flashing red signal indication:

Drivers legally entering the crosswalk on

a flashing (alternating or “wig-wag”) red

signal may conflict with pedestrians

clearing the crosswalk near the end of

the pedestrian clearance phase.

B

Eliminate the flashing red interval.

Introduce a split pedestrian phase.

2

duration of pedestrian clearance

interval: The pedestrian clearance

interval may be short, particularly for

elderly pedestrians.

B

Reduce assumed walking speed used

to calculate clearance interval.

3

interference from adjacent side streets

and driveways: Drivers turning into the

arterial road from adjacent side streets

and driveways may interfere with

pedestrians in the HAWK crossing.

B Enhance signing.

4

obstructed sightlines: Sightlines

between pedestrians entering the

HAWK crossings and approaching

drivers may be obstructed.

B

Post “No Parking” signs on selected

approaches.

Relocate near-side bus stops.

Relocate HAWK crossing at one site.

5

pedestrian desire lines: Pedestrians

may not use HAWK crossings that are

located away from apparent pedestrian

desire lines.

B

Observe desire lines before

determining HAWK location.

Enhance pedestrian signing.

6

night-time visibility at Speedway Blvd /

Rook Ave: Drivers may be confused by

competing background visual elements

at night.

B

Install reflective border around HAWK

signal.
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KEY LESSONS LEARNED:

The RSA process can enhance the implementation of innovative road safety measures with the

aim of promoting their success. This RSA focused on pedestrian crossing locations where the

HAWK device was to be installed. One of the outcomes of the RSA has been a set of suggestions

to enhance the HAWK system with a view to its wider (statewide or nationwide) application. In this

way, the RSA may have been beneficial as a means of reviewing the HAWK signal in a working

environment, identifying possible factors that may compromise its successful implementation

elsewhere, and suggesting measures to address them.

See also the discussion of “Key Factors for Success” and “Lessons Learned” in the main text.
ROAD SAFETY AUDITS: CASE STUDIES

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RSA NUMBER 9

STANDING ROCK SIOUX TRIBE (NORTH AND SOUTH DAKOTA):

RSA OF RESERVATION ROADS

Roads: existing two-lane rural tribal roads

RSA Sites: paved and gravel roadways (including secondary highways under State

jurisdiction) in rural and low-density urban environments

one small bridge

Environment: urban suburban rural

Owners: Standing Rock Sioux Tribe, Bureau of Indian Affairs, North Dakota DOT, South

Dakota DOT

Road Safety Audit

Date of RSA: 22-24 May 2005

RSA Stage(s): design stage RSA of existing roads

RSA team: staff from the Standing Rock Sioux Tribe, Federal Highway Administration (North

Dakota and South Dakota Field Offices), North Dakota DOT, South Dakota DOT,

Bureau of Indian Affairs, North Dakota State University, Northern Plains TTAP, and

Opus Hamilton

PROJECT BACKGROUND:

The Standing Rock Sioux Tribe (SRST) reservation in North and South Dakota extends over 2.3

million acres, with an extensive rural road network of BIA roads (about 200 miles) and county and

state roads (about 1,100 miles). The reservation roads connect the reservation’s communities to

each other and to the tribal administrative center in Fort Yates, ND. They also serve through traffic,

and provide access to the Tribe’s two casinos on Highway 24 near Fort Yates, ND (Prairie Knights

Casino) and Highway 12 near Mobridge, SD (Grand River Casino).

At the time of the RSA, the Standing Rock Sioux Tribe was actively pursuing improvements to

transportation infrastructure on the reservation. Under the SRST Transportation Department, the

Tribe had embarked on a long-range program to upgrade community transportation facilities,

including streets, sidewalks, street lighting, and storm sewers. The financing for this long-range

program, which was expected to cost $26.5 million, involved the innovative use of government,

tribal, and borrowed funds.

In addition to planning and implementing these improvements, the Tribe maintained its extensive

road network using its own funds as well as funding from sources such as the BIA. Maintenance of

tribal roads was a sensitive topic, since funding for maintenance involved an extensive government

allocation effort that limited the amounts available to reservations. At the same time, road

maintenance was viewed as an important responsibility that directly affected tribal efforts to build a
ROAD SAFETY AUDITS: CASE STUDIES

cohesive reservation community and promote economic activity. Maintenance of the roads on the

SRST reservation was a challenge due to their extent (connecting a population of about 9,000

spread over 850,000 acres) and the impacts of the Northern Plains environment (winter road

conditions, frost damage, and variations in the underlying water table). Although the SRST

reported that it fully utilized available government funds and its own funds, the RSA team observed

multiple maintenance-related issues on reservation roads, which are summarized as Issue 1 in

TABLE A.11.

Roads studied during this RSA included ND 24 and Highway 1806 (part of BIA 3), US 12, and

community access roads. Typical reservation roadways are shown in FIGURE A.13. The RSA

team drove these roads to identify safety issues associated with road geometry, traffic operations,

and maintenance. Although bridge inspection is not a usual part of the RSA process, the RSA

team was asked to observe possible maintenance issues associated with a bridge on BIA 3 at

Four-Mile Creek. RSA findings associated with the bridge were included in the RSA report.

BIA3 at intersection with ND24 south of Fort Yates, ND BIA 3 / Hwy 1806 in Kenel, SD

US 12 at Grand River Casino (left), near Mobridge, SD BIA 44 west of Mahto, SD

FIGURE A.13 VIEWS OF RSA SITES (STANDING ROCK SIOUX TRIBE RSA)

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KEY RSA FINDINGS AND SUGGESTIONS:

The key findings and suggestions of the RSA are summarized in TABLE A.11.

TABLE A.11 SUMMARY OF SELECTED SAFETY ISSUES AND SUGGESTIONS

STANDING ROCK SIOUX TRIBE RSA

SELECTED SAFETY ISSUE

(Number and Description)

RISK

RATING SUGGESTIONS

1

Road Maintenance: Limited

maintenance on reservation roads

contributes to poor pavement conditions

and concern regarding bridge stability.

B to D

control cracking with sawcut and fill

accommodate future overlays

bridge inspection and repair

2

Access to Grand River Casino: Drivers

turning into and out of the Grand River

Casino may interfere with crossing,

opposing, and following traffic on US12.

D

speed reduction

improved signing

westbound left turn bay

access relocation

3

BIA 31 and ND 24 (School Frontage):

Driver workload is potentially high near

the intersection of BIA 31 and ND 24,

which accommodates local, school, and

through traffic.

B to D

no-passing zone

crosswalk maintenance

enhanced signing

turning lanes on ND24

improved lighting

access consolidation

urban cross section

4

BIA 3 and Highway 1806 (Kenel):

Vehicle and pedestrian traffic may

interfere with through traffic on BIA 3

through Kenel.

B to D

marked crosswalk

regrading

urban cross section

relocation of grocery store

5

Hwy 1806 and US 12 (Jed’s Landing):

Driver workload is potentially high at the

intersection, which accommodates high

turning volumes and high speeds.

C

speed reduction

review of turning lanes

6

BIA 3 and ND 24: Left-turning vehicles

may obstruct through vehicles at

highway intersection on a horizontal

curve.

A left turn bay
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KEY LESSONS LEARNED:

The RSA team effectively combined disciplines, and included experts with relevant specialist

knowledge. The core disciplines that must be represented on any RSA team are traffic operations,

geometric design, and road safety. Beyond these core requirements, the Standing Rock RSA team

included members with a range of backgrounds and specialties, including State DOT members, a

member with specialist knowledge of pavement maintenance issues, and members familiar with

issues associated with tribal policies, practices, and conditions. This combination of backgrounds

and skills contributed to the Team’s understanding of the issues and constraints unique to this

RSA.

See also the discussion of “Key Factors for Success” and “Lessons Learned” in the main text.
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RSA NUMBER 10

YELLOWSTONE NATIONAL PARK:

RSA OF IMPROVEMENTS TO OLD FAITHFUL AREA

Project: replacement of existing interchange with new access

Planned Improvements: replacement of existing “interstate-style” interchange with at-grade access

revisions to existing parking facilities and circulation

Project Environment: urban suburban rural

Project Design Stage: conceptual (0 to 30%) preliminary (40 to 80%) advanced (over 80%)

Project Cost: < $100,000 $100,000 - $1,000,000 >$1,000,000

Project Owner: National Park Service

Road Safety Audit

Date of RSA: 31 May to 2 June 2005

RSA Stage(s): design stage RSA of existing roads

RSA team: staff from Federal Highway Administration Resource Center, Federal Highway

Administration Federal Lands, and Opus Hamilton

PROJECT BACKGROUND:

Yellowstone National Park, the world’s first national park and a designated World Heritage Site,

accommodates about 3 million visitors every year. The Old Faithful area (FIGURES A.14 and

A.15) is a popular destination within the Park, attracting about 85 percent of all Park visitors. Peak

visitor months are July and August, when the Old Faithful road network accommodates an average

daily traffic volume of about 6,000 vehicles.

At the time of the RSA, two planning-level concepts (FIGURE A.16) had been developed to replace

the existing Old Faithful interchange, which provided the only public access to Old Faithful Road

from the Grand Loop Road:

new east and west entry/exit points using two two-lane roundabouts that provide access to

and from Grand Loop Road and Old Faithful Road (“Concept 2B”),

a one-way circulation scheme connecting the Grand Loop Road and Old Faithful Road with

ramps (“Concept 8/8A”).

These two concepts were reviewed as part of the RSA. At the time of the RSA, these and other

alternative concepts were still under development, and were subject to substantial changes

pending completion of resource surveys and other data collection efforts.
ROAD SAFETY AUDITS: CASE STUDIES

Old Faithful Rd (Rt 17)

Old Faithful

main

parking

areas

Grand Loop Rd (Rt 10)

FIGURE A.14 RSA SITE (YELLOWSTONE NATIONAL PARK)

Old Faithful Road part of main parking area near Old Faithful geyser

FIGURE A.15 VIEWS OF RSA SITE (YELLOWSTONE NATIONAL PARK)

KEY RSA FINDINGS AND SUGGESTIONS:

Since construction of the interchange replacement was expected to start no sooner than 2009,

about four years after the RSA, the RSA also included a review of existing roads to identify lowcost countermeasures that could be implemented on an interim basis before the start of the

planned improvements. The focus of the RSA was the existing Old Faithful Road between the Old

Faithful interchange and the geyser site, including the geyser parking area, as shown in FIGURES

A.14 and A.15. The key findings and suggestions of the RSA are summarized in TABLE A.12. In

its response, the owner undertook to consider the RSA team’s observations in the final choice of

design options for access to the Old Faithful area, and to incorporate the RSA team’s interim

suggestions for pedestrian safety into planned improvements to the Old Faithful area.

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Option 2B Option 8A

one-way circulation

FIGURE A.16 PROPOSED IMPROVEMENTS TO OLD FAITHFUL AREA

TABLE A.12 SUMMARY OF SELECTED SAFETY ISSUES AND SUGGESTIONS

YELLOWSTONE NATIONAL PARK RSA

SELECTED SAFETY ISSUE

(Number and Description)

RISK

RATING SUGGESTIONS

RSA of Conceptual Plans

1

Issues Associated with Concept 2B:

driver unfamiliarity

two-lane roundabouts

mixing through and Old Faithful traffic

streams

traffic volume spikes

large vehicles in roundabouts

possible limited sight distance

downhill approach

pedestrians and cyclists in

roundabouts

B

signing

conservative design speed and

design volume

single-lane roundabouts with rightside bypass lane

appropriate design vehicle

control of roadside vegetation

anti-skid pavement

2

Issues Associated with Concept 8/8A:

short weaving segments

mixing through and Old Faithful traffic

streams

traffic volume spikes

possible limited sight distance

downhill approach

C

grade-separated ramps

conservative design volume

control of roadside vegetation

signing

anti-skid pavement
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SELECTED SAFETY ISSUE

(Number and Description)

RISK

RATING SUGGESTIONS

RSA of Existing Roads

3

Pedestrian Conflicts:

in parking area

at crosswalk on Grand Loop Road

D

Parking Area:

curb extensions

parking restrictions

curb ramps

raised crosswalks

conversion of roadway to pedestrian

zone

Grand Loop Road:

raised median

lighting

4

Conflicts in Old Faithful Loop Parking

Area B

restrictions on large vehicle parking

removal of front-in angle parking

stalls

5

Signing and Wayfinding:

driver guidance

pedestrian guidance

C

Vehicle Signing:

formal review of signing

Pedestrian Signing:

signing for geyser viewing area and

parking sub-areas

6 Old Faithful Interchange D

Interim measures:

roadside barriers

crash attenuators

improved signing and pavement

markings

Ultimate measure:

replacement of existing interchange

(as planned)
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KEY LESSONS LEARNED:

The RSA team and process may need to accommodate very specific demands and conditions.

The Old Faithful area represented a challenging environment in which to plan and implement road

improvements. Any proposed improvements were subject to environmental and historical

constraints, including fragile hydrothermal features and a desire to stay within existing roadway

footprints. At the same time, demands on the transportation infrastructure were considerable. The

roadways had to accommodate high concentrations of visitors, which often mixed with wildlife using

the roadway corridors. About 90 percent of Old Faithful vehicle traffic was composed of Park

visitors, with the result that a large proportion of drivers were unfamiliar with the road network, and

potentially were elderly retirees or were distracted by navigation demands. Traffic volumes varied

widely, reflecting large seasonal variations and, on Old Faithful Road, substantial outbound peaks

associated with a mass exodus following geyser eruptions. Similarly, within the Old Faithful visitor

and parking area, conflicting pedestrian and vehicle traffic both peaked following the regular geyser

eruptions. These factors, which were unique to the Park roadway environment, resulted in specific

demands and constraints, particularly regarding suggested mitigation measures.

See also the discussion of “Key Factors for Success” and “Lessons Learned” in the main text.
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FHWA-SA-06-17