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|Federal Highway Administration > Publications > Public Roads > Vol. 70 · No. 1 > Living To Tell the Tale|
Publication Number: FHWA-HRT-2006-005
Living To Tell the Tale
by Ann H. Do and David L. Harkey
A new version of PBCAT helps identify the maneuvers that lead to traffic crashes involving pedestrians and bicyclists so DOTs can select appropriate safety countermeasures.
On a sunny day in January 2006, an experienced bicyclist, Marc J., was pedaling near the edge of the travel lane on a narrow, rural road in Florida when he approached a green traffic light, where he intended to continue straight through the intersection. The driver of a pickup truck traveling in the same direction on the two-lane road reached the intersection at the same moment and made a right turn directly in front of Marc. The pickup truck and bicycle collided, and Marc was thrown hard onto the pavement. He sustained abrasions and a shattered thigh bone. After being airlifted out by helicopter, undergoing an operation, and enduring lengthy physical therapy, Marc is again able to bicycle. But his femur was permanently replaced by a titanium rod connected by metal pins to his knee joint and hip bone.
Marc was fortunate to have survived. Nationwide, 725 of his fellow bicyclists and 4,641 pedestrians were killed in traffic crashes in 2004, accounting for more than 12 percent of all traffic fatalities in the United States. An additional 68,000 pedestrians and 41,000 bicyclists were reported injured as a result of traffic crashes involving motor vehicles.
Reducing the number of traffic crashes that involve pedestrians and bicyclists requires knowledge of the actions that lead up to the incidents. Traditionally, the data contained in electronic crash files at State departments of transportation (DOTs) provide facts about where and when crashes occurred and who was involved. But the files often do not include an adequate level of detail about the sequence of events that led up to the crashes, and that information is needed before practitioners can select appropriate safety countermeasures. A new release of software from the Federal Highway Administration (FHWA) is intended to fill that gap and thus help improve walking and biking safety.
The new version of the software product, the Pedestrian and Bicycle Crash Analysis Tool (PBCAT) 2.0, which replaces PBCAT 1.0, is designed to help State and local pedestrian and bicycle coordinators, planners, transportation engineers, highway safety researchers, and health and safety officials develop and analyze databases that contain the information they need to select countermeasures.
"PBCAT 1.0 was groundbreaking in that it provided a sound method of creating good information where none previously existed," says John Madera, senior transportation planner with the Delaware Valley Regional Planning Commission (DVRPC), which is the metropolitan planning organization for the Philadelphia region. "PBCAT enabled planners, engineers, and the public to discuss, for the first time, facts rather than opinions."
Analysis of computerized State crash files can provide information on where pedestrian and bicyclist crashes occur, such as city, street, intersection, two-lane road, and so on; when they occur, including time of day and day of the week; and who is involved, that is, characteristics of the victims, such as their age and gender, plus the severity of their injuries. All of these data are useful for selecting safety countermeasures, but also critical are what happened and why it occurred — the type of crash.
Crash types are brief descriptions of the precrash actions of the parties involved. In the 1970s, the National Highway Traffic Safety Administration (NHTSA) developed methods for manually "typing" pedestrian and bicyclist crashes by defining the sequence of events and precipitating actions. In the early 1990s, FHWA applied the methodologies to more than 8,000 pedestrian and bicyclist crashes from 6 States. The results provided a representative summary of the distribution of crash types.
The crash typing methodology continued to evolve over time. FHWA refined it during development of version 1.0 of PBCAT, which was released in 1999. Version 1.0 automated the manual methodology for crash typing so that users could input data from police crash reports into a series of screens. At the end of the input process, PBCAT automatically assigned one of a number of pedestrian or bicyclist crash types. PBCAT saved the user's responses to each screen and the resulting crash type into a Microsoft® Access pedestrian/bicyclist database. The user could analyze the database to identify crash types and then select safety countermeasures to address those problems. PBCAT 1.0 provided links between crash types and appropriate countermeasures.
PBCAT version 2.0 does all of the same things and more. Version 2.0 lists 56 pedestrian crash types and 79 bicyclist crash types that fall under larger, more simplified crash groups — 16 for pedestrian-related and 21 for bicycle-related incidents — that allow users the option of grouping crashes in the larger categories, if desired. In the case of Marc's crash mentioned earlier, the most applicable selections are bicyclist simplified crash group 215 (motorist right turn/merge) and crash type 213 (motorist right turn - same direction). (See "Sample Bicyclist Crash Groups and Types From PBCAT".)
Version 2.0 Enhancements
The PBCAT 1.0 tool attracted more than 600 registered users in all 50 States and 28 countries.
"But any product can be made better, and PBCAT is no exception," says DVRPC's Madera. "Version 1.0 was based on database and operating system technology that had become obsolete. Also, the software had gained enough user experience over the years that could be tapped to make a better product."
The new version of PBCAT, released in July 2006, significantly improves the product's functionality. To make the software easier to use, the PBCAT 2.0 designers changed to the more familiar Microsoft® Windows® operating environment, which includes drop-down menus and toolbars. The designers also included a conversion utility for importing PBCAT 1.0 datasets into 2.0. In version 2.0, moreover, users may export data in several formats to conduct more sophisticated analyses using other applications, such as SAS® or Microsoft® Excel®.
Another change in PBCAT 2.0 relates to the design of the data entry forms. Users can customize the form to match the police crash reports used in the communities in their States. Customization helps expedite the input of crash data.
A third change, mentioned earlier, is the availability of group crash typing. For users who do not want the level of detail offered in the full list of crash types, there are 37 simplified crash groups for pedestrian and bicyclist crashes.
A fourth change enables users to record specific location information. For a pedestrian crash that occurred at an intersection, for example, users now can include the approach leg and travel direction of the parties involved. This allows users to perform crash type analyses and apply necessary countermeasures more accurately.
In addition, version 2.0 enables users to produce single variable and multivariable tables within the application, and they can export the results to Microsoft Excel for further customization and graphic production. Although PBCAT has some basic data analysis capabilities, the export feature enables users to perform robust data analyses using more powerful software packages such as Excel, SAS, or SPSS®.
Users of PBCAT 2.0 have access to detailed descriptions of engineering, educational, and enforcement countermeasures that address specific types of crashes. Each description includes a purpose, considerations, estimated cost, and access to real-world case studies.
Bike lanes, for example, are one of the countermeasures recommended for Marc's crash type 215 where the motorist failed to yield and turned right in front of the bicyclist. The countermeasure description for bike lanes indicates that their purpose is to create on-street travel facilities for bicyclists while narrowing the roadway to encourage slower motor vehicle speeds, provide additional separation between pedestrians and motor vehicles, and reduce the distance that pedestrians must walk when crossing automobile lanes.
The description suggests that special considerations include providing adequate space between the bike lane and parked cars so that open doors do not create a hazard for bicyclists. As for cost, installation of a bike lane ranges from approximately $3,100 to $31,000 per kilometer ($5,000 to $50,000 per mile), depending on the condition of the pavement, the need to remove and repaint the lane lines, the need to adjust signalization, and similar factors. It is most cost efficient to create bicycle lanes during street reconstruction, street resurfacing, or at the time of original construction.
A bike lane might help drivers be more aware that bicyclists are sharing the road and thus actually look for them. The pickup truck driver, then, might have seen Marc in time to stop and allow the bicyclist to continue safely through the intersection.
The PBCAT 2.0 software includes links to FHWA's Pedestrian Safety Guide and Countermeasure Selection System ("PEDSAFE" at www.walkinginfo.org/pedsafe) and FHWA's Bicycle Countermeasure Selection System ("BIKESAFE" at www.bicyclinginfo.org/bikesafe). PEDSAFE and BIKESAFE are Web-based tools that provide additional help with selecting countermeasures.
Real-World Applications: Pennsylvania
According to Madera, DVRPC used PBCAT 1.0 to type bicycle crashes that occurred from 1996 through 2001 in the part of Philadelphia known as University City. The typing was one component in a "Share the Road" public educational and informational campaign. The presentation of findings led to discussions between project stakeholders about enforcement and educational actions.
DVRPC also typed and analyzed pedestrian crashes that occurred in front of a commuter rail station in the Philadelphia suburbs. The agency recommended countermeasures based on its crash analysis, and the Pennsylvania Department of Transportation is designing roadway modifications based on those recommendations.
"Without access to good information, folks resort to making assumptions — often erroneous ones — about problems and solutions," says Madera. "The emphasis on safety mandated in the latest Federal surface transportation bill, SAFETEA-LU [Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users], provides new opportunities for PBCAT users. At DVRPC we plan to put version 2.0 to work uncovering patterns of pedestrian crashes at high-priority crash locations and recommending countermeasures to be included in a regional safety plan."
Already, DVRPC has uncovered a pattern of multiple-threat pedestrian crashes at a single midblock location in front of another commuter rail station — this one in Upper Darby Township, Delaware County, PA. A multiple-threat crash results when a pedestrian enters a traffic lane in front of slowing or stopped traffic and then is struck by traffic traveling in the same direction in the adjacent lane. Countermeasure recommendations from PBCAT 2.0 include constricting the road to one lane by direction and installing a raised median at that location.
Researchers with the Wisconsin Department of Transportation (WisDOT) explored the potential of PBCAT 1.0 when developing the State's pedestrian plan and then used the beta version of PBCAT 2.0 to generate bicycle crash types for 2002-2004. WisDOT also analyzed the most frequent bicycle crash types, along with roadway characteristics, to develop commonalities among the crashes. Crash locations were geocoded to relate the crashes to local and State highway data files. The crashes then were cross-referenced by roadway, traffic, and intersection physical characteristics to determine the commonalities and whether roadway and traffic conditions were contributing factors.
Mike Amsden, research analyst with WisDOT, has been working with the beta version of PBCAT 2.0 since June 2005. "It uses a set of straight-forward, easy- to-understand diagrams and situations for crash typing," says Amsden. "It also simplifies crash typing and generates many more crash types than one could develop by just looking at a police report."
WisDOT currently is conducting a comprehensive bicycle crash analysis for the State, slated for completion in summer 2006. The manager of the State's bicycle and pedestrian safety program soon will be using the most common crash types identified in the study for educational and enforcement efforts.
As part of the Miami-Dade Comprehensive Bicycle Safety Plan, Herman Huang, project planner with Sprinkle Consulting, Inc., used the beta version of PBCAT 2.0 to help perform an extensive bicycle crash analysis for Miami-Dade County, FL. Huang obtained hardcopies of police crash reports for bicycle crashes in Miami-Dade County and used PBCAT 2.0 to assign a crash type to each incident. The analysis included crash typing more than 1,300 bicycle crashes, a detailed review of the crash reports, and field investigations of high-crash locations. The purpose of this extensive analysis was to determine the engineering, enforcement, and educational countermeasures that could be implemented to reduce the bicycle crash rate in Miami-Dade County.
"PBCAT contains limited analysis capabilities," says Huang, "so we exported the database into Microsoft Excel for indepth analysis. The tool allowed us to look at crash trends to determine general intervention-type countermeasures."
He found that the PBCAT analysis of crashes in Miami-Dade County revealed that many were the result of poor judgment on the part of bicyclists, resulting in unsafe behaviors. The most common example of these behaviors was a bicyclist turning into a motorist's path.
The North Carolina Department of Transportation's (NCDOT) Division of Bicycle and Pedestrian Transportation crash types every incident involving pedestrians or bicyclists and motor vehicles that occurs in the State each year and adds that data to its Web site (www.pedbikeinfo.org/pbcat/index.htm), which now contains information on more than 26,000 crashes from 1997 through 2004. The reports involving pedestrians and bicyclists are downloaded, printed, and used to type the crashes. Before beginning to use PBCAT 1.0 in 1996, NCDOT already had a robust database that included all the variables in police crash reports.
After analyzing the crashes, NCDOT produces an annual report on the state of pedestrian and bicyclist safety. Posting the information on the Web site enables State and local agencies, as well as the public, to access the reports and produce customized queries.
In 2005, for example, NCDOT studied a major corridor for the town of Chapel Hill and crash typed all motor vehicle crashes with pedestrians and bicyclists for the last 5 years for background data. Bill Hunter, senior research scientist, The University of North Carolina Highway Safety Research Center, currently is crash typing pedestrian-motor vehicle crashes for an NHTSA senior pedestrian safety project in Hendersonville, NC.
The Bottom Line
Throughout FHWA, the guiding principle is commitment to ensuring safe travel on roadways. If FHWA and the States are to achieve the 2008 goal of reducing the fatality rate to 1.0 per million vehicle miles traveled, pedestrian and bicyclist traffic crashes need to be addressed aggressively. For the new Pedestrian and Bicycle Crash Analysis Tool, the bottom line defining its value will be the lives saved and suffering reduced.
"Improvements to the road will help us keep on pedaling and live longer," says Marc J.
Ann H. Do is a research highway engineer at FHWA's Turner-Fairbank Highway Research Center in McLean, VA. She has been the program manager for FHWA research on pedestrian and bicycle safety since 2001 in the Office of Safety Research and Development. She has a B.S. in civil engineering from Virginia Polytechnic Institute and State University.
David L. Harkey is the interim director and a senior research engineer at The University of North Carolina's Highway Safety Research Center. He has more than 20 years of experience applying transportation engineering principles and research evaluation methodologies to improve highway safety. One area of emphasis has been the development of tools for practitioners, like PBCAT 2.0.
PBCAT 2.0 will be available in late summer 2006. To download the software, visit www.fhwa.dot.gov/research/tfhrc/, www.walkinginfo.org, or www.bicyclinginfo.org. For more information, contact Ann Do at 202-493-3319 or email@example.com.
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