U.S. Department of Transportation
Federal Highway Administration
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Federal Highway Administration Research and Technology
Coordinating, Developing, and Delivering Highway Transportation Innovations
This magazine is an archived publication and may contain dated technical, contact, and link information.
|Publication Number: FHWA-HRT-2006-001 Date: November/December 2006|
Publication Number: FHWA-HRT-2006-001
Issue No: Vol. 70 No. 3
Date: November/December 2006
Transportation professionals employ audits to scrutinize roadways for safety issues—and reduce crashes, injuries, fatalities, and costs in the process.
|In this photo from Oregon, a team of transportation professionals confers during a road safety audit (RSA) on a stretch of U.S. 97.|
For more than 10 years, the number of fatalities on U.S. roadways has remained at a plateau of about 42,000 deaths annually. Although the fatality rate on U.S. roadways has decreased remarkably to 1.46 deaths for every 100 million vehicle miles (MVMT) traveled, further improvements are vital. The number and rate of deaths are unacceptable to the Nation, the Federal Highway Administration (FHWA), and partners such as the American Association of State Highway and Transportation Officials (AASHTO), the Institute of Transportation Engineers (ITE), the National Association of County Engineers (NACE), and the American Public Works Association (APWA).
In 2005, nearly 3 million people were injured and some 43,200 killed on U.S. roadways. That means there were 117 traffic fatalities every day on average, including one road departure fatality every 21 minutes, one intersection fatality every hour, and one pedestrian fatality every 2 hours. There are economic implications as well: a "societal cost" of $230 billion annually, or $630 million daily, according to FHWA.
One of numerous initiatives to reduce the crash rates is FHWA's promotion of road safety audits (RSAs) as a proactive means of reducing deaths and injuries. FHWA first studied RSAs in 1996 in a 2-week "scan" of audits in Australia and New Zealand (see the September/October 1997 issue of Public Roads ).
An RSA is a formal examination of the safety performance of a roadway or intersection by an independent, multidisciplinary team of transportation professionals. RSAs are a comprehensive and effective tool for proactively improving road safety while a facility is still in the planning or design stage, or for identifying and mitigating safety issues on existing roadways.
Identifying a problem before it becomes part of the infrastructure is a preferable approach. As a manual on RSAs by Austroads, an association of road transport and traffic authorities in Australia and New Zealand, indicated: "It is easier, quicker, and cheaper to change a pencil line on a drawing than to move concrete and asphalt after the job is built."
FHWA's Office of Safety, Office of Infrastructure, Resource Center, and Highways for LIFE (HfL) team work with AASHTO's Technology Implementation Group to champion RSAs. The HfL team assists the FHWA Office of Safety with marketing expertise and funding to speed implementation of RSAs across the country, building on the inroads already made. The purpose of the HfL program is "to advance longer lasting highway infrastructure using innovations to accomplish the fast construction of efficient and safe highways and bridges" (thus spelling out "LIFE"). HfL uses "innovations" as a broad term to cover technologies, materials, tools, equipment, procedures, specifications, methodologies, and processes or practices used in the finance, design, or construction of highways.
Many State departments of transportation (DOTs) have shown increased safety resulting from the process. "The road safety audit process looks at the roadway from a purely technical safety viewpoint without outside influences," says Ricky Lee May, district engineer with the Mississippi Department of Transportation. "It is a valuable process that gives an unbiased view of safety issues with support from safety experts."
In short, RSAs can make safe roads even safer.
Most DOTs have established traditional safety review processes through their high-hazard identification and correction programs. However, an RSA and a traditional safety review are different processes. Generally, an RSA involves more people from more disciplines who are looking only at the issue of safety and have not been involved in the project's design or implementation. This approach allows for greater objectivity and a fuller report on a roadway's safety problems.
RSAs help produce designs that may reduce the number and severity of crashes, promote awareness of safe design practices, and reduce costs by identifying safety issues and correcting them before projects are built. Highway authorities formally respond to the suggestions of the RSA team and either implement its suggestions or document the reasons for not doing so.
|Traditional Safety Reviews||RSAs|
|Performed by a safety review team that is usually not completely independent of the design team.||Performed by a team independent of the project.|
|Typically performed by a team with only design and/or safety expertise.||Performed by a multidisciplinary team.|
|Often concentrate on motorized traffic.||Consider all potential road users.|
|Do not normally consider human-factor issues.||Account for road user capabilities and limitations as essential elements of an audit.|
|Often do not generate a formal report.||Always involve generating a formal RSA report.|
|Often do not generate a formal response report.||Always include a formal response report.|
Source: Road Safety Audit Guidelines (FHWA-SA-06-06).
The keys to success in implementing an RSA program are top-level agency support, willingness to incorporate findings, and willingness to investigate new ideas outside the traditional scope of work. The small, multidisciplinary audit teams should include members from the highway/traffic safety, traffic engineering, planning, operations, geometric design, construction, maintenance, human factors, or enforcement fields. Also integral to success is conducting RSAs at the earliest possible stage of project development.
Steps in an RSA Process
States on the Move
Several State DOTs and local agencies have incorporated RSAs into their existing efforts to enhance safety. The following sampling highlights a few RSA programs around the country without being an all-inclusive list. Looked at in conjunction with activities in other States such as Florida, Illinois, Michigan, South Carolina, Wisconsin, and elsewhere, the list demonstrates that the momentum for RSAs is building.
Evaluation of RSAs has been more extensive in Australia and New Zealand than in the United States. Austroads has documented favorable benefit/cost ratios for RSAs, but the early returns on RSAs in the United States are positive as well. For example, Terecia Wilson, safety director for the South Carolina Department of Transportation (SCDOT), sees a beneficial impact from the State's program: " We view RSAs as a proactive, low-cost approach to improve safety," she says. "The RSAs helped our engineering team develop a number of solutions incorporating measures that were not originally included in projects. The very first audit conducted saved SCDOT thousands of dollars by correcting a design problem."
SCDOT has conducted six RSAs since 2003. The results of these RSAs (two of them are described below) are now available, and while SCDOT officials acknowledge that the findings are preliminary, they believe that the numbers are promising. In the RSA of SC-14 in Greenville County, SC, nine safety improvements were suggested, and all were implemented. Fatalities on that highway were reduced by 60 percent from 2003 to 2004, avoiding more than $3.6 million in estimated potential economic losses. In Spartanburg County, an SCDOT audit of SC-296 in 2003 led to a 23.4-percent reduction in crashes in 2005. Of 37 safety recommendations, 25 were adopted, and the economic benefit is estimated at $147,000.
In Michigan, a public-private partnership was formed to improve intersection safety. The partnership included AAA Michigan, the city of Detroit, city of Grand Rapids, Wayne County, Michigan DOT, Southeast Michigan Council of Governments, the Michigan Office of Highway Safety Planning, and Wayne State University. The partnership conducted RSAs on 250 intersections in Detroit and Grand Rapids. Of those, more than 80 have been evaluated. Collectively, these intersection improvements resulted in a more than 25-percent reduction in total crashes and more than 40-percent in injury collisions. The benefit/cost ratio exceeded 16 to 1 over 10 years.
|These before (above) and after (below) photos depict the intersection of 7 Mile Road and Dequindre Road in Detroit, MI. An RSA in 2002 led to, among other changes, placement of a left-turn arrow on the pavement to improve roadway navigation and safety. Photos: AAA Michigan.|
In late 2004, FHWA's Office of Safety initiated a series of 10 RSAs that will be documented in a book of case studies to show the variety of applications in different parts of the country, on different roads and intersections, and at different stages of the project development process. The full report, containing summaries of RSAs conducted by the Oklahoma Department of Transportation (DOT); Clark County, WA, DOT; the city of Cincinnati, OH, transportation department; the Standing Rock Sioux Tribe transportation department in North and South Dakota; plus those listed below, can be found on FHWA's Web site in early winter 2007: http://safety.fhwa.dot.gov/rsa/.
Illinois . The Illinois Department of Transportation (IDOT), which uses the term "assessments" instead of "audits," uses RSAs as a tool to look at locations that have had a history of severe crashes and to identify safety issues, their risks, and potential low-cost countermeasures. Sample findings from the RSAs include signage issues, existence of vulnerable users (pedestrians and bicyclists), turning-radius issues, signal displays out of alignment, clear-zone violations, drainage grates that are unfriendly to bicyclists, trees in medians showing evidence of being struck, exposed culverts, and openings in guardrails. IDOT has hosted three RSA training courses taught by FHWA and plans to host one in each of the State's districts.
Yellowstone National Park . In May 2005, an FHWA team conducted an RSA in the Old Faithful area of the park, specifically from Black Sand Basin to Kepler Cascades. Currently, traffic conflicts occur between pedestrians and vehicles after each eruption of the geyser, and issues also exist with signage and the geometry and operation of one of the park's overpasses. The short-term mitigation measures identified during the RSA include changing the traffic flow to reduce posteruption conflicts, developing signing and way-finding plans, and providing a shoulder plus exclusive merge/diverge lanes at the overpass. Longer term remedies suggested include using roundabouts, considering older-driver needs, maintaining emergency response and government access routes, matching road design with speed, and considering context sensitive gateways.
Collier County, FL . In 2002, the FHWA team conducted an RSA on a project at the conceptual stage, which involved widening a section of Immokalee Road from two lanes to four. To accommodate current and forecast demands, Collier County now is considering additional widening to six lanes.
The RSA suggestions included improved access management features, right-turn acceleration lanes, devices and designs to prevent wrong-way movements, signal operation and median treatments to prevent midblock crossings, pedestrian countdown signals, a continuous pedestrian network, improvements to existing bicycle facilities, avoidance of fixed objects and sight-line obstructions in the median, angled left-turn lanes in wide medians, redundant signal displays and/or double red displays for left-turn signals, backplates with reflective borders on traffic signals, coordinated traffic signal progressions, and considerations of the needs of older drivers. Collier County has since decided to establish a program of regular RSAs and has consultants on retainer for future projects.
City of Tucson, AZ . FHWA's team conducted an RSA of a corridor where the HAWK ( High-intensity Activated cross Wal K) pedestrian crossing device had been installed. The HAWK is a type of traffic control beacon developed by Tucson for marked pedestrian crosswalks and currently is approved for experimentation under the Manual on Uniform Traffic Control Devices (MUTCD) and is under consideration for inclusion in the next edition of the MUTCD. The RSA suggested placing "no passing" lines in crosswalk approaches, activating the dual red lights simultaneously, using split phasing for median-divided streets, using reflective-border backplates, lowering the walking speed to 1.1 meters (3.5 feet) per second for all crossings (not just school crossings), and making connections to pedestrian facilities.
Wisconsin . In December 2003, an RSA on the Marquette Interchange (I-43, I-94, and I-794) was the first done on a megaproject in the United States. The RSA team was limited in what it could feasibly review given the volume of documentation associated with the $800 million project, its advanced design stage, the completion of the public involvement process, and the limited time available for the RSA.
Nevertheless, the team identified six categories of safety issues, ranging from location-specific to general project conditions, for WisDOT to consider for improving the new design. Suggestions included revising advance signage for a specific ramp, adding flexible delineators or lengthening concrete barriers to reduce the chance of inappropriate exiting maneuvers, improving pavement markings at various locations, conducting additional microsimulation modeling, signalizing and coordinating ramp intersection traffic movements, restricting certain movements, improving pedestrian accommodation at several intersections, providing higher barrier heights on several ramps, placing ramp speed limit advisory signs, adding "gawk screens" to avoid motorists being distracted at work zones, considering some street closures and turning restrictions during construction, and changing construction staging to reduce traffic on certain streets.
S.C. Stands for Scrutiny and Concern
For an idea of the exacting nature of RSAs, one needs to look no further than SCDOT District 3. In June 2003, a three-person team from outside the district, with expertise in road design and traffic engineering, audited a completed project on Greenville County's SC-14, in District 3. The project widened a section of SC-14 from two lanes to three, with the center lane as a dedicated left-turn lane or a two-way left-turn lane.
The audit team first reviewed relevant data and documentation, including plans for the project, intersection crash and traffic volume data, and profiles (plans showing the vertical alignment of the road design), and also interviewed the District 3 construction engineer. Then the team drove the relevant section several times, stopping often to view areas of concern more closely, over the course of 1.5 hours. In the end, the team offered nine suggestions:
"Overall, the project is constructed satisfactorily," the auditors wrote in their report. "No major design issues were noted. Provided the items above are addressed, this portion of SC-14 should provide for many years of safe and efficient travel."
Important to note is that despite the project being essentially sound, the RSA was able to turn up "marginal" modifications that saved lives and millions of dollars.
Nearly all transportation projects have some degree of pedestrian activity; even roadways in remote areas may serve walkers from time to time. Walkers may not be explicitly or adequately considered in some transportation projects, however, due to a lack of training for traffic engineers on meeting pedestrian safety needs. This lack of training factor makes it critical that pedestrian safety be incorporated into the RSA process.
Accordingly, FHWA is developing a report, Pedestrian Road Safety Audit Guidelines, and a companion "Pedestrian Road Safety Audit Prompt List" that can be used together during the RSA process. These resources will contain detailed information on issues that audit teams should address. Delivery is expected in early 2007.
Instead of checks to verify that minimum standards are being met, the prompt list will guide auditors to look for potential issues, such as those that are not addressed by vehicle-oriented standards or those that can arise from minimum or inappropriate standards.
The guidelines will parallel the prompt list and will provide a more detailed explanation of potential issues. Photographs of good and poor designs will provide examples.
Instead of focusing exclusively on pedestrian needs and issues, the guidelines and prompt list will look at how pedestrians and other modes interact. For example, can a driver see pedestrians waiting or attempting to cross? Are left-turning drivers so focused on finding gaps in conflicting traffic that they may neglect to look for crossing pedestrians? Do larger corner radii, which make it easier to turn a corner without slowing down, encourage higher speeds?
|The city of Tucson developed HAWK signals, such as the one shown here, specifically to aid pedestrians at crosswalks. An RSA recommended changes to the device and roadway environment around it that improved safety for pedestrians even more.|
FHWA offers two RSA training courses for transportation professionals in State and local transportation agencies and tribal governments. The first is a 2-day course available through the National Highway Institute (NHI), called Road Safety Audits and Road Safety Audit Reviews, FHWA-NHI-380069. Information on course scheduling can be found online atwww.nhi.fhwa.dot.gov. The second course, RSA for Locals, is geared toward local agencies, tribal governments, and Federal land management agencies. This course is free and can be presented in 1-day or 2-day formats, with the longer course including information on low-cost safety improvements and a field exercise RSA. (For more information about the RSA for Locals course, contact the author of this article.)
Because technical or procedural questions often arise before and during an RSA, FHWA has established the RSA Peer-to-Peer (P2P) program to provide assistance, at no cost, to agencies either considering the use of or actually conducting RSAs. A State, local, or tribal agency may request assistance either by e-mail at SafetyP2P@fhwa.dot.gov or by calling the toll-free number 1-866-P2P-FHWA and talking with the FHWA-sponsored P2P coordinator. The coordinator will match the agency with a knowledgeable transportation professional. The matched peer then will contact the agency to work out the details of the assistance, which may include a site visit as needed.
RSAs can have an important impact on the safety of the Nation's roads and intersections. To receive assistance in implementing the RSA process, contact the local FHWA division office or contact the author of this article directly.
|During an RSA training exercise, a team performs an onsite inspection at an intersection in Tampa, FL.|
Louisa Ward is the RSA program manager for FHWA's Office of Safety. She has worked in various roles in FHWA for the last 7 years. She previously worked for the Institute of Transportation Engineers as its technical program manager for traffic engineering and safety, and as the assistant traffic engineer for the city of Kettering, OH. Ward received her bachelor's degree in civil engineering from the University of Dayton.
For more information, or to schedule the RSA for Locals course, contact Louisa Ward at 202-366-2218 or firstname.lastname@example.org. For Resource Center technical assistance on RSAs, contact Craig Allred at 720-963-3236 or email@example.com. To contact the RSA P2P program, call 866-P2P-FHWA or e-mail SafetyP2P@fhwa.dot.gov. For pedestrian RSAs, contact Gabriel Rousseau at 202-366-8044 or firstname.lastname@example.org.