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 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:
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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.
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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.
The FHWA RSA Case Study Program
The ten RSAs conducted in this case study program are summarized in Table 1.
| 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.