Safety Data Analysis Tools Workshop

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Uses, Benefits, and Current Status of GIS in
Safety and Planning Applications

• Safety Data Analysis Tools Workshop

Transportation Safety Planning Working Group
March 27-28, 2006
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GIS-Based Safety Management Systems

• Basis for development
• Highway Safety Improvement Program
• Collect and maintain safety data
• Identify hazardous locations
• Conduct engineering studies
• Establish project priorities
• Schedule and implement
• Determine the effect of safety improvements
• Safety Analyst
• Provide state-of-the-art analytical tools for use
  in the decision-making process to identify and
  manage a system-wide program of site-specific
  improvements to enhance highway safety by
  cost-effective means

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Benefits of GIS

• Collect data once, use many times
• Reduces data collection costs
• Improves data accuracy
• Improves data consistency
• Reduces data maintenance costs
• Reduces time needed to access data
• Promotes better decision-making for safety
• Improved public safety

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Conceptual Framework for SMS/GIS
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Conceptual Framework for SMS/GIS

• Inventory collection/maintenance of all data
  elements
• Assess process data, establish parameters, find
  locations
• Analyze diagnose critical locations, establish
  costs/benefits
• Model synthesize data into optimal resource
  allocation
• Evaluate determine countermeasure
  effectiveness
• Program develop implementation plans
• Publish generate standardized and ad hoc reports

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SMS/GIS Functionality
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SMS/GIS Functionality
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Geospatial Data Inventory

• Purpose
• Collect/integrate safety safety-related
  geospatial data
• Integrate into SMS database
• Safety data warehouse
• Types of Inventory
• Crash data (local, regional, statewide)
• Road inventory, including functional
  classification
• Traffic volumes
• Pavement data
• Road safety improvements (past, present, future)
• High crash locations
• Potentially hazardous locations

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Geospatial Data Inventory

• Data is most critical system element
• Data must be designed
• To be feasible to collect/generate
• To be of sufficient quality
• To produce essential information
• Data design must be output driven
• What information is essential?
• What information will add value?
• Will the data produce this information?

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Geospatial Data Inventory

• Data typically 70-80 of project cost
• Collection, aggregation
• Conflation, merging, etc.
• Quality checks
• Often neglected in technical specs
• Use of available data
• New data sources and capabilities
• Enhance data accuracy/timeliness
• Enlarge analytical capabilities

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SMS/GIS Functionality
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Geospatial Data Assessment

• Purpose
• Characterize safety of roads, intersections, and
  network
• Compute accident rates for roads and
  intersections
• Develop safety rating index for roads and
  intersections
• Determine overall crash characteristics by type
• Aggregate safety rating for areas and locations
• Find locations indicated to be hazardous or
  potentially hazardous
• Data quality, conformance to standards
• Other potential assessment indicators

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Data for SMS/GIS

• Crash Data
• Varies significantly by state
• Standards within the State are required
• State/Local coordination is necessary to achieve
  standards for capture and data models
• Geo-location element is critical for success
• Standard naming conventions are also critical
• Use of a common base map
• Should use one of the standard LRMs
• Time stamp the crash date
• Current GIS approaches can locate to 1/100 mile

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Data for SMS/GIS

• Traffic Data
• Traffic counts are important
• They are used for crash rate calculations and
  other statistics
• They typically start as sparse point data and
  need to be filled in
• Data is needed for both State and local levels

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Data for SMS/GIS

• Highway Classification
• Functional classification
• Number of lanes
• Divided or undivided
• Access control
• Type of area (urban, rural, suburban)

• Hazardous Highway Features
• Blunt end guard rails
• Slippery pavement sections
• Narrow lanes or shoulders
• Non-break away signs supports
• Rigid light pole supports
• Inadequate horizontal or vertical curves
• Poor sight distances
• Non-uniform or inadequate traffic control devices

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SMS/GIS Functionality
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Analyze/Diagnose

• Purpose - to generate
• Identify anomalies
• Conformance to current standards
• Location statistical analysis
• Location summary reports
• For location investigations
• Location visualization
• Crash report visualization
• Countermeasure development
• Alternative strategies per location
• System considerations
• Countermeasure cost
• Safety benefit determination

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SMS/GIS Functionality
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Model/Optimize

• Purpose
• Optimize countermeasure strategy
• Maximum possible benefit
• Subject to funding limitation
• Fit within feasible schedule
• Maximize benefit over entire network
• Model
• Effects on safety classification
• Countermeasure strategies
• Safety benefit
• Cost
• External priority
• Schedule
• Develop priority listings

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SMS/GIS Functionality
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Evaluate

• Purpose
• Monitor the performance of the countermeasures
• Estimate countermeasure effectiveness
• Adjust collision reduction factors for
  countermeasures

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SMS/GIS Functionality
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Program/Publish

• Purpose
• Transform technical allocations into real plans
• Develop multi-year program from modeling
  information
• Tabulate improvement, budget, and schedule
• Quantify projected improvements in safety
• To Publish
• Statewide safety program
• Statewide safety statistics
• Area safety statistics

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Pedestrian Bicycle Safety

• Safe Routes to School
• Locations for new bicycle routes
• Pedestrian crash zones

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Pedestrian Bicycle Safety

• Uses GIS data not typically captured in roadway
  inventories
• Sidewalks
• Curb lane widths
• Crosswalk locations
• Applications
• Shortest/safest/preferred routes
• Bicycle compatibility
• Location of high crash zones

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Analytical Tools

• National Cooperative Highway Research Program
  (NCHRP) Report 546 Incorporating Safety into
  Long-Range Transportation Planning
• Appendix C Safety Tools
• Project level
• Regional level
• Corridor level
• Require differing levels of data and expertise
• Proactive and reactive
• Differing levels of analysis more generalized
  to more detailed

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GIS at the State level

• 2006 AASHTO GIS-T Symposium
• Ongoing improvement in accuracy of geospatial
  data, particularly with road centerline databases
• Other data collected maintained include
• Other transportation network features
• Political administrative boundaries
• Geodetic control points
• Orthoimagery
• Elevation
• Water features
• Parcel boundaries

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GIS at the State level

• 2006 AASHTO GIS-T Symposium
• Respondents asked to list up to four current GIS
  activities
• Reponses were ranked based on cites
• GIS priorities determined
• The survey noted that
• GIS also seems to be used more frequently in
  specific analysis and planning application,
  particularly safety and crash analyses,
  environmental impact studies, and traffic and
  bridge management systems.

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GIS at the State level
GIS Activity of Citations
Development of web-based GIS application 44
Linear referencing system development / enhancement 15
Enterprise data warehouse 14
Road inventory management system / attribute data 13
Migration to new GIS hardware and software 13
Road centerline database development / enhancement 13
Data sharing partnerships / coordination 12
Orthoimagery data collection / integration 10
Traveler advisory / information system application 10
Development of other geo-spatial databases 10
Safety / crash analysis 9
ITS / traffic management applications 8
Project management applications 8
Environmental / cultural mitigation applications 7
Bridge management applications 7
GIS strategic planning / needs assessment 6
GPS data collection / integration 5
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GIS at the MPO level

• AMPO Survey Technical Priorities (February
  2005)
• On a scale of one to ten, several broad
  categories, followed by more specific
  subcategories within each

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GIS at the MPO level
Technical Resources/Solutions 6.72
Best practices - planning practice and institutional issues 6.82
Safe Streets 6.29
Intelligent transportation systems 6.22
Safety 6.16
Transit-oriented and transit-ready development 5.95
Context sensitive design 5.91
Complete Streets 5.85
Systems operations in general 5.78
Security 5.54
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Hilary Perkins, AICP, GISPJacobs Civil,
Inc.314.335.4909hilary.perkins_at_jacobs.com

• Many thanks to
• Gerald Dildine
• ITIS-Corp

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Questions/Discussion