RISK-BASED MANAGEMENT OF GUARDRAILS: SITE SELECTION AND UPGRADING

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RISK-BASED MANAGEMENT OF GUARDRAILS SITE
SELECTION AND UPGRADING

• Presented to
• The Project Steering Committee
• by
• The Center for Risk Management of Engineering
  Systems
• September 15th, 2000

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Project Team
VDOT Richmond District Travis Bridewell, District
Traffic Engineer, Richmond District Jeff
Wilkinson, Transportation Engineer, Traffic
Engineering Section, Richmond District Baron
Gissendaner Virginia Transportation Research
Council Wayne S. Ferguson, Research Manager
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


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Project Team (cont.)
Additional Current and Former Resident
Engineers Bill Bushman Angela Tucker Willie
Gentry Alan Leatherwood Dan Roosevelt Center for
Risk Management of Engineering Systems James H.
Lambert, Research Assistant Professor of Systems
Engineering Yacov Y. Haimes, Quarles Professor of
Systems Engineering and Civil Engineering and
Center Director Jeffrey A. Baker, BS/MS
Student Kenneth Peterson, Undergraduate
Student Capstone Team Christian Baldwin Irene
Jacoub Mike Raker
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Agenda

• I. Motivation
• II. Data representation for Hazard Catalog
• III. Data representation for Corridor Screening
• IV. Data representation for Site Prioritization
• V. Discussion

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I. Motivation
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Motivation

• Public and transportation-agency priorities
  concerning the location of roadway guardrails are
  in need of clarification
• The concerns of Virginians for adequate
  guardrails relative to national norms are high
• Current practice in some VDOT Districts for
  selecting locations for new guardrails is based
  upon citizen complaints, a general knowledge of
  roadway needs from local engineers, and accident
  history

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Motivation (cont.)

• E.g., there are hundreds of candidate locations
  on the thirteen-county secondary system of
  Richmond District over 50,000 miles of roadway
  in Virginia
• Kentucky developed a hazard-index point system
  (Kentucky Transportation Center Report KTC-89-39
  "Warrants and Guidelines for Installation of
  Guardrail")
• Particular locations in New Kent and Charles City
  County were the focus of a related preliminary
  study in Richmond District

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Purpose and Scope

• Objectives
• Review and evaluation of what others have done
• Adoption of assessment methods and quantitative
  and qualitative factors
• Development of a tradeoff methodology
• Specification and prototype development of
  databases

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Overview of Approach

• A data driven approach to assessing risk and
• evaluating safety of candidate guardrail
  locations by
• Catalog
• Screening phases
• Evaluation phases
• Data needs in a case study
• Developing Software

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Corridor Screening

• Select corridors to examine

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Site Prioritization

• Select locations along given corridor

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New Kent Case Study

• Data Collection for Corridor Screening Tool
• Accident statistics of given corridors
• Routes 601-665
• Data Collection for Site Prioritization and
  Hazard Catalog Tool
• Routes 611, 613, 640, 665

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II. Hazard Catalog Tool
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Purpose

• Compile an inventory of hazard sites and
  guardrail coverage, and conditions of guardrails
• Compare and contrast routes to determine which
  are in need of further study
• Present in a graphical format information
  pertinent to decisions about improvements

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Severity Guidelines
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Hazard Catalog Screening
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Hazard Catalog Screening (cont.)

• Size of bubbles represent cost/value

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Hazard Catalog Screening (cont.)
Size of bubbles represent cost
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Hazard Catalog Screening (cont.)
Size of bubbles represent cost/value
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IV. Corridor Tool
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Purpose

• Compare corridors for frequency and severity of
  accidents
• Highlight corridors that have greatest
  accidents/DVMT ratio
• Compare results with current guardrail coverage

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Corridor Screening
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Corridor Screening (cont.)
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IV. Site Prioritization Tool
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Purpose

• Decide which sites should be improved with the
  current budget constraint
• Consider multiple criteria

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Objective (cont.)
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Objectives of Guardrail Selection
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Example

• Maximize length of hazard protected
• Subject to budget constraints
• (E.g. total cost lt 30,000)

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Site Prioritization Tool Analysis

• Compare sites and their characteristics (cost,
  severity, ADT)
• Select routes with the highest benefit/cost
  ratios that fall within a budget constraint

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Site Prioritization
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Site Prioritization (cont.)
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Site Prioritization (cont.)
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Site Prioritization (cont.)
Size of bubbles represent cost/value ()
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Site Prioritization (cont.)
Size of bubbles represent cost/value ()
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Site Prioritization (cont.)
Size of bubbles represent cost/value ()
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Comparison of Results

• Results can be compared to show the consistency
  of need at a location
• Budget constraint kept constant
• Example
• Locations 1,2,3,7, and 9 are recommended by the
  model to maximize severity protected

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Summary and Future Work

• The spreadsheet tools provides a way to optimally
  select hazard sites within the budget constraints
• Comparing results from different solutions can
  reveal the locations most appropriate for
  improvement

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Summary and Future Work (cont.)

• Issues for Implementation
• Definition of Severity
• Environmental Factors
• Curvature of Road

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Web Page

• http//www.virginia.edu/risk/guardrail/
• Public reference for guardrails and treatment of
  issue
• Communication between VDOT and Capstone
• Software, instructions, and powerpoint

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The Web Site

• Statement of Work
• Guardrail Photos
• Current Team
• Contact Information
• Related Links
• Downloads

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Discussion