Center for Risk Management of Engineering Systems University of Virginia, Charlottesville 1 RISK-BASED MANAGEMENT OF GUARDRAILS: SITE SELECTION AND UPGRADING Presented to Project Steering Committee Virginia Department of Transportation by the Center for Risk Management of Engineering Systems April 17, 2000

Center for Risk Management of Engineering Systems University of Virginia, Charlottesville 2 Agenda Introduction Risk-based screening of corridors Data representation for site screening Multiple objectives in the selection among candidate sites Software demonstrations Discussion

Center for Risk Management of Engineering Systems University of Virginia, Charlottesville 3 Project Team Center for Risk Management of Engineering Systems James H. Lambert, Research Assistant Professor of Systems Engineering, Center Associate Director Yacov Y. Haimes, Quarles Professor of Systems Engineering and Civil Engineering and Center Director Jeffrey A. Baker, BS/MS Student Christian R. Baldwin Irene A. Jacoub Mike R. Raker Virginia Transportation Research Council Wayne S. Ferguson, Research Manager VDOT Richmond District Travis Bridewell, District Traffic Engineer, Richmond District Jeff Wilkinson, Transportation Engineer, Traffic Engineering Section, Richmond District Baron Gissendaner

Center for Risk Management of Engineering Systems University of Virginia, Charlottesville 4 Project Team (cont.) Additional Steering Committee Steve Edwards, Transportation Engineer Senior, Traffic Engineering Division, Central Office Paul Kelley, Transportation Engineer, Location and Design Division, Central Office Charlie Kilpatrick, Fredericksburg Resident Engineer, Fredericksburg District Bob McCarty, Senior Field Operations Engineer, Federal Highway Administration - Richmond Ginger Quinn, District Safety Officer, Traffic Engineering Section, Salem District Nancy Berry, Transportation Engineering Program Supervisor, Location and Design Division, Central Office Bill Bushman, Virginia Transportation Research Council Angela Tucker, Resident Engineer Willie Gentry, Resident Engineer Alan Leatherwood, Resident Engineer

Center for Risk Management of Engineering Systems University of Virginia, Charlottesville 5 Problem Statement Public and transportation-agency values concerning the location of roadway guardrails in need of clarification Concerns of Virginians for adequate guardrails high relative to the national norms VDOT Districts select locations for new guardrails based on citizen complaints, a general knowledge of roadway needs from local engineers, and accident history

Center for Risk Management of Engineering Systems University of Virginia, Charlottesville 6 Problem Statement (cont.) Kentucky hazard-index point system (Kentucky Transportation Center Report KTC "Warrants and Guidelines for Installation of Guardrail") Hundreds of candidate locations on the thirteen-county secondary system of Richmond District New Kent and Charles City County the focus of a related preliminary study in Richmond District

Center for Risk Management of Engineering Systems University of Virginia, Charlottesville 7 Purpose and Scope Identify attributes and develop associated cost-benefit-risk tradeoff methodology to support screening and evaluation for guardrail site selection and upgrading with limited available funding

Center for Risk Management of Engineering Systems University of Virginia, Charlottesville 8 Purpose and Scope (cont.) Objectives –Review and evaluate what others have done –Adopt assessment methods –Develop tradeoff methodology –Specify and develop prototype databases

Center for Risk Management of Engineering Systems University of Virginia, Charlottesville 9 Screening of Corridors

Center for Risk Management of Engineering Systems University of Virginia, Charlottesville 10 Evaluation of Sites

Center for Risk Management of Engineering Systems University of Virginia, Charlottesville 11 Risk Based Screening of Corridors

Center for Risk Management of Engineering Systems University of Virginia, Charlottesville 12 Motivation A data-driven approach to assess accident risk and associated guardrail needs across Districts and Residencies

Center for Risk Management of Engineering Systems University of Virginia, Charlottesville 13 Data Needs Screening –Guardrail inventories Percent unprotected hazards Percent guardrail coverage Percent substandard guardrail –Accident histories FO accidents per DVMT Fatalities caused by FO accidents –Average daily traffic –Complaint records

Center for Risk Management of Engineering Systems University of Virginia, Charlottesville 14 Data Needs (cont.) Evaluation –Cost (installation, upgrade) –Length of hazard –Severity of hazard –Shoulder width –Slope –Curvature

Center for Risk Management of Engineering Systems University of Virginia, Charlottesville 15 Accident Statistics Disadvantages –Unreported accidents –Severity iceberg –First and most harmful event –Fatalities do not occur frequently enough to be statistically predictive –Random nature of road accidents (Adams, 1996), (Michie and Bronsted, 1994)

Center for Risk Management of Engineering Systems University of Virginia, Charlottesville 16 Accident Statistics (cont.) Advantages –Available –Factual –Public interest (Adams, 1996), (Michie and Bronsted, 1994)

Center for Risk Management of Engineering Systems University of Virginia, Charlottesville 17 New Kent Case Study Initial data collection –Routes Corridor analysis –Collect data –Perform calculations (accidents per mile, accidents per DVMT) –Generate tables and graphs

Center for Risk Management of Engineering Systems University of Virginia, Charlottesville 18 Corridor Analysis Compare routes for frequency and severity of accidents Compare accident statistics with guardrail coverage Advantages –Reduce randomness of individual accidents –Use summary statistics available in HTRIS

Center for Risk Management of Engineering Systems University of Virginia, Charlottesville 19 Corridor Analysis (cont.) Disadvantages –Does not focus on individual locations –E.g., many locations of mediocre severity vs. one location of very high severity

Center for Risk Management of Engineering Systems University of Virginia, Charlottesville 20 Data Acquisition

Center for Risk Management of Engineering Systems University of Virginia, Charlottesville 21 Corridor Screening [Similar treatment of accident counts and accidents per DVMT]

Center for Risk Management of Engineering Systems University of Virginia, Charlottesville 22 Corridor Screening (cont.) Example graph –Run off the road accidents per DVMT

Center for Risk Management of Engineering Systems University of Virginia, Charlottesville 23 Data Representation for Site Screening

Center for Risk Management of Engineering Systems University of Virginia, Charlottesville 24 Motivation Need to organize data on many hazards protected and unprotected by guardrail on 40,000 miles of roadway across Virginia

Center for Risk Management of Engineering Systems University of Virginia, Charlottesville 25 Sample of Guardrail Inventory