1. 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

2. Why Crash Analysis Systems? n >100 persons killed/day (>37,000 in 1996) n 8.8 million crashes per year in USA n 2.3 million injuries n vast amount of uncoordinated data n powerful/low cost computing n potentially huge B/C source: NHTSA 1997

3. Past/present ALAS (PC-ALAS) n PC-based system n User-friendly interface, easy to learn n About 700,000 crashes over 10 years n Provides easy access to data n 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

4. Past/present ALAS

5. CAD Node Maps

6. Current Difficulties n Node numbers must be identified from tables or paper maps n Difficult to analyze patterns n Does not readily support integration of additional data n Hard to identify crash “hot spots” and to analyze causes and countermeasures

7. GIS-ALAS Project Goals n Develop geographic/map-based ALAS n Use power of GIS n Portable, accessible, windows based n Free users from node maps n Statewide coverage n Supports highway safety analysis n Facilitate integration with other data

8. Crash Locations text Text - node ID, x, y MapBasic interpolation program MapInfo Crash Locations CAD node file MGE (unit conversion) Text - node ID, lat, long MapInfo Node Locations Paper crash records DB2 - ID - from node - to node - distance - crash information MIF ArcView Crash Locations x’ y’

9. Roadway and Crash Coverages

10. 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 -... Crash Information Paper crash records MapBasic defines 3 tables A, B and C MapInfo text MIF ArcView Crash Information (for ArcView-ALAS) text fortran ABBBC ArcView Crash Information (for Explorer-ALAS)

11. Background Data IDMS Base Records (DOT) - ADT - pavement type - lane width -... CAD Roads (DOT) - State - County - Local Text file - vertices - information MapInfo/MapBasic aggregate to county level MIFArcView CAD Hydrology (DOT) DXF Rail (BTS) BTS preprocessor

12. Block Groups, Crashes, and Business Coverages

13. Alcohol-Related Crashes and Tavern Locations

14. Benefits of Customization n technology transfer - similar interface to PC-ALAS n users don't need to know (much) GIS n users don't need to be database experts – variable names and labels (e.g., 3 = icy surface conditions) n increased flexibility in interface (e.g., choosing crashes by selection box, link/node (as in PC-ALAS), or city/county/region) n enhanced display, e.g., standardized colors, defined zooms, "stacking" of crash points n standardized reports, e.g., for enforcement, engineering n easier to do queries across counties, regions, years, tables n works with relational data structure of crash files

15. Relational Data Structure of Crash Files

16. Avenue Scripts

17. Opening AV-ALAS

19. Opening View

21. Opening Tabular Data

22. Selecting Region

24. Selecting Counties

25. Selecting Cities

26. Selecting Cities within Multiple Counties Recounting Selected Crashes

27. Refining Search

30. Viewing Reports

32. Additionally... n Point location specifications – by node – by crash location – by link n Utilize GIS environment – logical queries – spatial queries – thematic maps – buffering – additional data sources – more...

33. Logical Query

34. Spatial Query

35. Thematic Map - Crashes by Time of Day

36. Thematic Map - Crashes by Age

37. Thematic Map - Crashes by Surface Conditions

38. Applications: Collision Diagram Software

39. Emergency Response Applications n Emergency response areas n Nearest facility/shortest path to crash n Impact of “Avenue of the Saints” on emergency response n CODES - linking crash and hospital records

40. Emergency Response Times

41. Aerial photo integration

43. www.ctre.iastate.edu GIS Projects

44. GIS-ALAS