GIS-ALAS: Locating and Analyzing Crash Locations within a GIS Environment National Highway Traffic Safety Administration 1999 Region Seven Data Conference June 8-10, 1999
Why Crash Analysis Systems? >100 persons killed/day (>37,000 in 1996) 8.8 million crashes per year in USA 2.3 million injuries vast amount of uncoordinated data powerful/low cost computing potentially huge B/C source: NHTSA 1997
Past/present ALAS (PC-ALAS) PC-based system User-friendly interface, easy to learn About 700,000 crashes over 10 years Provides easy access to data Several Uses: obtain accident statistics by time and location query database by accident/driver characteristics generate reports on-screen, to a file, to the printer
Past/present ALAS
CAD Node Maps
Current Difficulties Node numbers must be identified from tables or paper maps Difficult to analyze patterns Does not readily support integration of additional data Hard to identify crash “hot spots” and to analyze causes and countermeasures
GIS-ALAS Project Goals Develop geographic/map-based ALAS Use power of GIS Portable, accessible, windows based Free users from node maps Statewide coverage Supports highway safety analysis Facilitate integration with other data
Crash Locations CAD node file Text - node ID, x, y Paper crash records MGE (unit conversion) DB2 - ID - from node - to node - distance - crash information Text - node ID, lat, long y’ MapInfo Node Locations x’ MIF text MapBasic interpolation program MapInfo Crash Locations ArcView Crash Locations
Roadway and Crash Coverages
MapBasic defines 3 tables A, B and C Crash Information MapBasic defines 3 tables A, B and C MIF MapInfo Paper crash records ArcView Crash Information (for ArcView-ALAS) text DB2 - ID - location information - A (crash) records - B (driver 1) record - B (driver 2) record - … - C (1st 3 injuries) record - C (2nd 3 injuries) record - ... text fortran ABBBC ArcView Crash Information (for Explorer-ALAS)
Background Data IDMS Base Records (DOT) - ADT - pavement type - lane width - ... CAD Roads (DOT) - State - County - Local CAD Hydrology (DOT) Rail (BTS) DXF Text file - vertices - information BTS preprocessor MapInfo/MapBasic aggregate to county level MIF ArcView
Block Groups, Crashes, and Business Coverages
Alcohol-Related Crashes and Tavern Locations
Benefits of Customization technology transfer - similar interface to PC-ALAS users don't need to know (much) GIS users don't need to be database experts variable names and labels (e.g., 3 = icy surface conditions) increased flexibility in interface (e.g., choosing crashes by selection box, link/node (as in PC-ALAS), or city/county/region) enhanced display, e.g., standardized colors, defined zooms, "stacking" of crash points standardized reports, e.g., for enforcement, engineering easier to do queries across counties, regions, years, tables works with relational data structure of crash files
Relational Data Structure of Crash Files
Avenue Scripts
Additionally... Point location specifications Utilize GIS environment by node by crash location by link Utilize GIS environment logical queries spatial queries thematic maps buffering additional data sources more...
Logical Query
Spatial Query
Thematic Map - Crashes by Time of Day
Thematic Map - Crashes by Age
Thematic Map - Crashes by Surface Conditions
Applications: Collision Diagram Software
Emergency Response Applications Emergency response areas Nearest facility/shortest path to crash Impact of “Avenue of the Saints” on emergency response CODES - linking crash and hospital records
Emergency Response Times
Aerial photo integration
CTRE Crash Location Tool Kansas City June 1999
Outline The National Model Current Iowa Location Procedure Advantage Safety Development and Demo
The National Model Project Goal: Shorten collection time Minimize traffic disruption Increase officer efficiency and safety Improve data quality
The National Model Projects: Data Collection Expert System GPS Location Crash Data Collection Process Smart Police Vehicle Systems Integration Technology Sharing and Assistance
Current Location Process
Current Data-Flow Chart PC-ALAS Paper Officer Report Bottleneck Access ALAS Central Office Location Processing of Literal Description ALAS Paper Driver Report Link / Node to XY GIS-ALAS
Advantage Safety
Proposed Flow-Chart Advantage Safety w/LocTool (Office) Local Data Analysis Paper Officer Report XY to Link / Node Translator PC-ALAS Paper Driver Report Access ALAS Central Office Location Advantage Safety w/LocTool (Enterprise) ALAS Advantage Safety w/LocTool (Mobile) GIS-ALAS
Crash Location Improvement Crash location performed on-site or at local office Geographic coordinates of crash Roadway information confirms location Key fields identified for base record ID and future cartographic upgrade
Software Selected ESRI MapObjects Microsoft Visual Basic Arcview Shape Cartography Data from DOT Spatial Data Warehouse (Oracle) Distributed as a DLL
Coordinate Information Location Tool GUI User Interface Menu Main Map Window Coordinate Information
User Interface Menu Pan Map Previous View View Entire Map Zoom In/Out Crash Locate Tool Pan Map Zoom In/Out Previous View View Entire Map
Location Finders Coordinate Milepost County City Intersection
Demonstration Corporate Limits Milepost Marker Crash Location
Snap Location
www.ctre.iastate.edu GIS Projects
GIS-ALAS