Alternative%20Database%20System

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Alternative Database System

• HSIS (Highway Safety Information System) combined
  with GIS
• Incorporates many databases such as crash
  inventory, roadway inventory, traffic signal
  inventory, and ADT
• User interface allows data to be edited,
  analyzed, and exported
• Supports graphical displays, point-and-click
  selections, pull-down and pop-up menus
• Crash analysis
• Supports five searching methods
• All methods allow user to designate variables to
  be reported

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Crash Analysis

• Spot/Intersection Analysis
• Evaluate accidents at a user designated spot or
  intersection
• Strip Analysis
• Examine crashes along a designated length of
  roadway
• User enters a route and length of segment
• Program automatically searches consecutive strips

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Crash Analysis (cont.)

• Cluster Analysis
• Study accidents around a given roadway feature
• Sliding-Scale Analysis
• Identify high accident roadway segments
• Program memorizes all strips that exceed accident
  threshold
• Corridor Analysis
• Locates high crash areas within a corridor

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New Kent Case Study

• Initial Data Collection
• Routes 609-622
• Corridor Analysis
• Corridors for which guardrail inventory is
  available
• Routes 33, 106, 249, 273

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Corridor Analysis

• Compare routes for frequency and severity of
  accidents
• Select routes that have greatest accidents/miles
• Compare results with current guardrail inventory
• Advantages
• Reduce random chance associated with accidents
• Use summary statistics available in HTRIS

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Corridor Analysis (cont.)

• Disadvantages
• Overlooks role of hazardous locations
• Many locations of mediocre severity vs. one
  location of very high severity

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Initial Analysis
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Initial Analysis (cont.)
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Initial Analysis (cont.)
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Initial Analysis (cont.)
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Initial Analysis (cont.)

• Route 249 (Using Total Accidents as measure)

• Route 106 (Using FO accidents/miles and FO
  accidents/DVMT as measure)

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Initial Analysis (cont.)

• Route 273 (Using Total FO accidents as measure)

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Future Work

• Conclude screening
• Comprehensive corridor analysis
• Examine evaluation methods
• Risk assessment and safety evaluation
• Examine the safety state model
• Suggest Safety alternatives

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Motivation

• Ability to compare multiple projects with a
  graphical user interface (GUI)
• Assist resource allocation
• Decision support
• More evidence to the table, sooner
• Demonstrate with New Kent Countys guardrails

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Mission Statement

• Develop a GUI for a guardrail and hazard
  inventory system for resource allocation and
  decision making

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Visualization of New Kent

• Graphically represent what resident engineers
  know using an electronic map indicating the
  locations of
• Guardrails
• Obstacles
• Accidents
• Complaints, etc.

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Electronic Map (Map 1)
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Electronic Map

• Map of New Kent/route 249 area
• Similar to the zoomed in view on standard maps
• Only concerned with guardrail sites, candidate
  sites, and accident data

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Legend

• R, L, R, L
• Side of road on which guardrail is located,
  indicates substandard guardrail
• C1, C2, C3, Cn
• C citizen complaint
• n number of complaints

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Legend (cont.)

• O
• Obstacle
• A1, A2, A3, An
• A Accident
• n number of accidents

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Legend

• Same functionality as the New Kent County maps
  legend with different symbols
• Guardrails
• Obstructions
• Complaints
• Accidents

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Integration of Map and Catalog

• The data visualized on the map comes from the
  catalog
• Users able to retrieve the data they want via the
  map

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Example Functionality

• When a user selects a guardrail site, the
  information in the catalog about that site is
  displayed
• Location, type, direction, length, etc.
• When a user selects a route, that information is
  displayed
• Guardrail prevalence, ADT, accidents, etc.

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Zoomed In (Map 2)
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Zoomed In (Map 3)