PSYCHOLOGY 409A April 24, 2006

Outline 10:

MODELING HAZARDOUS LOCATIONS WITH GEOGRAPHIC INFORMATION SYSTEMS

By Lincoln James Whyte

Arthur, Robert M., (2002). Modeling Hazardous Locations with Geographic Information Systems. In Rothe, J. Peter (ed.), Driving Lessons: Exploring Systems That Make Traffic Safer (pp.257- 269). Edmonton: University of Alberta Press.

Instructions for this activity are found at:
www.soc.hawaii.edu/leonj/leonj/leonpsy24/g24-oral1.htm
Instructor: Dr. Leon James

Geographic Information Systems

There are certain spots that seem to be more prone to accidents such as certain stretches of highway, a particular intersection, etc. Geographic information systems (GIS) can be used to assess how hazardous these areas are. The geographic characteristics of these high risk areas can be looked at to determine how to re- engineer them and other areas with the same features.

What is GIS?

• A system that is relatively new to traffic safety research but that has huge potential to improve current methods.
• Is very helpful in assessing why certain hot spots have so many accidents
• Computer system designed for acquisition, storage, manipulation, analysis, display of geographical data.
• Developed from computer-assisted design (CAD), database-management systems (DBMS), and spatial query language (SQL).
• Uses raster (grid of small cells and pixels) and vector data models (points, lines, polygons).
• In the Calgary study described in the book, the GIS system included information such as collectors, major streets, highways, traffic flow, speed limits, divided/ undivided roadways, bridges, railroads, zoning such as residential, industrial, and reserve or park, the location/ road conditions/ driver characteristics/ car make/ time of day/ weather/ and severity of all the accidents during the timeframe under study

Temporal Dimension:

• Comparing accident frequencies before and after intervention.
• Ignored by current engineering research.
• Some interventions may alleviate problems at high frequency accident times as intended, such as rush hour, but then end up increasing accidents in the same spot during other times.

Applications of GIS:

· Shows traffic volume trends for different times, days, and weeks.

· Can be used to help design and build roadways as well as maintain, monitor, and re-engineer them.

· Helps identify locations of high accident frequency and can find ways to correct the problem area.

· for example, in the Calgary study they found differences in high risk zones between rush hour during the week and late nights on the weekend. They conclude the rush hour creates certain risks in certain intersections, while weekend nights create different problems at different locations. This can help explain the need for different intervention measures. The rush hour risk zones may need re-engineering while the late night risk zones need police presence. Late night (and early morning) accidents include higher speeds and alcohol presence and thus are more dangerous and need to be addressed in a different way than the slower speed but more common and less fatal rush hour accidents (Late night accidents are more frequent for the amount of vehicles on the road, that is a higher proportion of them are at risk).

· GIS can point out differences in accident rates before and after interventions during all possible hourly, diurnal, and weekly patterns.

· GIS can calculate difficult and tedious calculations and data collection and organization. This is useful because traffic analysis incorporates such a wide range of data measures and is often unreliable and incomplete.

· Helps identify problems specific to certain locations such as industrial, rural, or residential areas.

GIS on its own is not enough to solve the problems associated with driving but is one of the many useful tools that need to be incorporated with other means such as education and enforcement to improve traffic conditions. Much of the data that is currently needed for the full application of GIS is not available and thus its use is restricted to areas with well documented and detailed data. This is changing though and GIS will become increasingly beneficial to increasing traffic safety.

Related Links:

1) What is GIS?

http://www.gis.com/whatisgis/ This link provides further information of what GIS is as well as links to other information involving uses of GIS, its importance and other information regarding GIS.

2) GIS on Wikipedia

http://en.wikipedia.org/wiki/GIS This link is to www.wikipedia.com ‘s entry on GIS and includes a definition as well as many other links to learn about what GIS is, how it was developed, how it is and can be used, and other useful information.

3) Evaluation of Accident Black Spots on Roads using Geographical Information Systems (GIS)

http://www.gisdevelopment.net/application/utility/transport/mi03038.htm This article shows how GIS is used to deal specifically with improving road conditions in hazardous areas that are accident hot spots.

My Home Page: http://www.soc.hawaii.edu/leon/409as2006/whyte/home.htm

G24 Class Home Page: http://www.soc.hawaii.edu/leonj/leonj/leonpsy24/classhome-g24.htm