Safety Data Analysis Tools Workshop March 27-28, 2006 Uses, Benefits, and Current Status of GIS in Safety and Planning Applications Transportation Safety

Safety Data Analysis Tools Workshop

March 27-28, 2006

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

Transportation Safety Planning Working Group

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GIS-Based Safety Management Systems

Basis for development: Highway Safety Improvement Program

o Collect and maintain safety datao Identify hazardous locationso Conduct engineering studieso Establish project prioritieso Schedule and implemento Determine the effect of safety

improvements Safety Analyst

o 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

Evaluate Implementation

Planning

Inventory AssessmentAnalyze / Diagnose

Model / OptimzeProgram / PublishEvaluate

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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

Functions

Inventory Assess Analyze Model Evaluate Program Publish

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Functions


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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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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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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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Functions


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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

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

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

suburban)

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Functions


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Analyze/Diagnose

Purpose - to generate: Identify anomalies Conformance to current standards Location statistical analysis Location summary reports

o For location investigations Location visualization Crash report visualization Countermeasure development

o Alternative strategies per locationo System considerations

Countermeasure cost Safety benefit determination

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Functions


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Model/Optimize

Purpose Optimize countermeasure strategy

o Maximum possible benefito Subject to funding limitationo 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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Functions


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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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Functions


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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

o Project levelo Regional levelo 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:o Other transportation network featureso Political & administrative boundarieso Geodetic control pointso Orthoimageryo Elevationo Water featureso Parcel boundaries

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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 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

4.16

5.56 5.51

6.726.28 6.27

0123456789

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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

Hilary Perkins, AICP, GISPJacobs Civil, [email protected]

Many thanks to:Gerald DildineITIS-Corp

Questions/Discussion

Documents

Safety Data Analysis Tools Workshop March 27-28, 2006 Uses, Benefits, and Current Status of GIS in Safety and Planning Applications Transportation Safety