GIS Applications in Traffic Accidents

Hongtao Gao

GIS Applications in Transportation

• Transportation planning

• Highway design

• Traffic routing (navigation)

• Traffic tracking

• Accident location and analysis

Accident Application

Geo-referenced Accident database

• The traditional accident database is a summary spreadsheet format using codes and mileposts to denote location, type and severity of accidents.

• Geo-referenced accident database is location-referenced. It incorporates a GIS graphical interface with the accident information to allow for query searches on various accident attributes.

GIS-based accident analysis

• Identify accident historical trends

• Identify accident-prone locations

• Analyze relationships in accident causation

-volumes, v/c, LOS, road conditions,

weather, and lighting, etc.

GIS-based accident report • Table style or graphical style

-One graph can represent thousands of words; importantly, the graph can display some features that words can not represent

• Choose any features that you interest to report

• Before or after analysis

• Can obtain accident statistics for locations during specified time period; you can identify accidents of specific types or involving driver with certain characteristics.

• The final reports can be printed using pre-defined formats

Example 1 of GIS Accident application projects

• GIS-ALAS (GIS-based Accident Location and Analysis System)

- A locationally-referenced highway accident database created by the Iowa Department of Transportation (DOT), law enforcement agencies, Iowa State University, and several other entities.

-GIS-ALAS reproduces query and reporting functions in a graphical environment that facilitates advanced spatial query and display capabilities.

-GIS-ALAS provides graphical data access, enabling the user to view and select desired locations on the network, Query results can be displayed in both map and tabular form, thereby creating more easily interpreted query results and promoting the analysis of accident patterns and causal relationships.

Accident pin map GIS-ALAS

Accident Display in terms of locations (GIS-ALAS )

Example 2 of GIS Accident application projects

• AIMS:GIS (Accident Information Management System: Geographic Information System)

AIMS:GIS is a GIS-based program originally developed for the

City of San Francisco by JMW Engineering, Inc. The program runs on

Windows 95, and uses MapInfo 4.1 to operate the GIS portion of the

program. The program allows the user to select intersections or links

by manual input or point and click selection from the map. Once an

intersection or link is selected, a collision diagram can be generated.

Other features of AIMS:GIS are the ability to plot worst accident

locations, provide annual reports, and perform queries.

Accident display in terms of time AIMS:GIS

Analysis report in terms of locations AIMS:GIS

Example 3 of GIS Accident application projects

• CUAA (Champaign-Urbana Accident Analysis)

Purpose of this project

-Identify and display current accident trends

-Highlight dangerous intersections and corridors

-Provide visual reference in order to identify areas needing improvement

Accident report(CUAA)

Accident analysis output(CUAA)

Accident report(CUAA)

Conclusion

• Geo-referenced accident database is easy to access,

display, visualize, query, analyze, and combine data from

other database by using GIS.

• GIS provides powerful tool for analysis, makes visual

identification of hazardous locations simple

• GIS provides flexible and visual report functions