District of Columbia 2006 Five Percent Report

This report is in response to the Federal requirement that each state describe at least 5 percent of its locations currently exhibiting the most severe highway safety needs, in accordance with Sections 148(c)(1)(D) and 148(g)(3)(A), of Title 23, United States Code.  Each state’s report is to include potential remedies to the hazardous locations identified; estimated costs of the remedies; and impediments to implementation of the remedies other than costs.  The reports included on this Web site represent a variety of methods utilized and various degrees of road coverage.  Therefore, this report cannot be compared with the other reports included on this Web site.

Protection from Discovery and Admission into Evidence—Under 23 U.S.C. 148(g)(4) information collected or compiled for any purpose directly relating to this report shall not be subject to discovery or admitted into evidence in a Federal or State court proceeding or considered for other purposes in any action for damages arising from any occurrence at a location identified or addressed in the reports.

Additional information, including the specific legislative requirements, can be found in the guidance provided by the Federal Highway Administration,
http://safety.fhwa.dot.gov/safetealu/fiveguidance.htm.

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District of Columbia Department of Transportation
Traffic Services Administration
City Wide Support Division

Highway Safety Improvement Program (HSIP)
2006 Annual Report

HSIP – 5 Percent Report

The Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU) creates the Highway Safety Improvement Program (HSIP) as a “core” FHWA program and provides a significant amount of funding to support highway safety improvement program (HSIP).  The purpose of HSIP is to achieve a significant reduction in traffic fatalities and severe injuries on public roads.  States are required to identify 5 percent or more of their public road locations experiencing fatal and severe injury crashes.  Based on the requirement, DC Department of Transportation identifies those locations using measures such as number of crashes, number injury crashes, and number of injuries.  This report also provides a list of potential remedies for each of locations, the estimated costs of the remedies and impediments to the implementation.

Methodology

The Traffic Accident Reporting and Analysis System (TARAS), maintained by the City Wide Support Division of the Traffic Services Administration, is the primary tool for documenting traffic crash data, analyzing traffic patterns, and identifying crash-prone locations.  A total of 17,018 crashes were reported to have occurred on Washington D.C. public roads in 2005.  There were 5,196 crashes involving at least one injured person, among which 44 were fatal crashes. 

The number of fatal crashes occurring in the District of Columbia is too small to constitute a database from which significant statistics can be derived.  DDOT, in cooperation with the major Crash Unit of the District of Columbia Metropolitan Police Department (MPD), investigates all fatalities and orders traffic signals, signing and pavement marking improvements when required.  A cursory examination of locations where fatalities have occurred shows no significant trends, which could evolve into a program of effective countermeasures.  As a result, fatal crashes have been included in the database of personal injury crashes, which is more substantial and offers more possibilities for the development of engineering countermeasures.

The TARAS is not sophisticated enough to differentiate between injuries and severe injuries which include fatal injuries.  DDOT has a code for injury severity for each involved person in the person-involved database.  However, there is no such code in the main TARAS database, which would allow us to differentiate injuries by severity.  Technically, based on the current PD-10 table, we could do that, but it would take some time to get it processed.  In addition, if we use the national ratio of incapacitating injury to fatality (7.22), the number incapacitating injuries in DC are estimated to be 354 for 2005.  This number is still too low to statistically scientifically identify high hazard locations using the number of incapacitating injuries at each location.

It is further noted that TARAS only uses intersection ID as a unique identifier to record and categorize each crash by location.  Mid-block crashes are not clearly recognized in the TARAS database and many are frequently assigned as occurring at the nearest intersection.  Interstate and freeway crashes are recorded in the TARAS database, but their precise locations cannot be established because neither TARAS nor the police report is currently tied to a GIS platform.  As a result, DDOT focuses upon intersection-related crashes when categorizing locations as high hazard.

DDOT uses three categories of crash statistics to define high hazard: the total number of crashes at an intersection, the number of injury crashes at an intersection, and the total number of injuries at an intersection.  Intersections are ranked from most severe to least severe in all three categories.  DDOT has established crash and injury thresholds to determine high hazard locations.  Intersections featuring twelve or more crashes per year, four or more injury crashes per year and five or more injuries per year are the established thresholds in each category, respectively.  DDOT reported 245 intersections featuring 12 or more crashes, 315 intersections experiencing 4 or more injury crashes, and 392 intersections with 5 or more injuries in 2005.  DDOT subsequently determined that 13 intersections with 12 or more annual crashes, 16 intersections experiencing 4 or more injury crashes and 20 intersections featuring 5 or more injuries constitute the top five percent high hazard intersections in each category.

DDOT has defined the top five percent high hazard intersections as those appearing in all three reporting categories at the five percent level.  An examination of all categories shows that all thirteen identified in the 12 or more annual crashes category are also represented in each of the other two reporting categories.  Therefore, the top five percent high hazard intersections in the District of Columbia are the following:

Table 1 District of Columbia 2005 High Hazard Locations

The SAFETEA-LU legislation requires that potential remedies be identified for each of the intersections in the five percent listing.  The estimated cost of the potential remedies and implementation impediments shall also be documented for each of the intersections.  This information is detailed in Table 2.

District of Columbia Department of Transportation
Traffic Services Administration
City Wide Support Division Phone: (202) 671-1493
2000 14th Street NW 2nd Floor
Washington, DC 20009