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?
>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

3. 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

4. Past/present ALAS

5. CAD Node Maps

6. 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

7. 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

8. 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

9. Roadway and Crash Coverages

10. 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)

11. 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

12. Block Groups, Crashes, and Business Coverages

13. Alcohol-Related Crashes and Tavern Locations

14. 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

15. Relational Data Structure of Crash Files

16. Avenue Scripts

17. 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...

18. Logical Query

19. Spatial Query

20. Thematic Map - Crashes by Time of Day

21. Thematic Map - Crashes by Age

22. Thematic Map - Crashes by Surface Conditions

23. Applications: Collision Diagram Software

24. 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

25. Emergency Response Times

26. Aerial photo integration

28. CTRE Crash Location Tool
Kansas City
June 1999

29. Outline The National Model Current Iowa Location Procedure
Advantage Safety
Development and Demo

30. The National Model Project Goal: Shorten collection time
Minimize traffic disruption
Increase officer efficiency and safety
Improve data quality

31. The National Model Projects: Data Collection Expert System
GPS Location
Crash Data Collection Process
Smart Police Vehicle
Systems Integration
Technology Sharing and Assistance

32. Current Location Process

33. 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

34. Advantage Safety

35. 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

36. 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

37. Software Selected ESRI MapObjects Microsoft Visual Basic
Arcview Shape Cartography
Data from DOT Spatial Data Warehouse (Oracle)
Distributed as a DLL

38. Coordinate Information
Location Tool GUI
User Interface Menu
Main Map Window
Coordinate Information

39. 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

40. Location Finders
Coordinate
Milepost
County
City
Intersection

41. Demonstration
Corporate Limits
Milepost Marker
Crash Location

42. Snap Location

43.
GIS Projects

44. GIS-ALAS