Presentation Title: Safety Data Analysis Utilizing GIS Technology
Michael Pawlovich
Crash Analysis Engineer
Iowa DOT Office of Traffic and Safety
800 Lincoln Way, Ames, Iowa 50010
E-mail: Michael.pawlovich@dot.state.ia.us
Dan Gieseman
Center for Transportation Research and Education
Iowa State University
2901 S. Loop Drive, Suite 3100
Ames, Iowa 50010-8615
E-mail: dgiesema@iastate.edu
This presentation will describe two new software packages for analysis of Iowa crash and other safety data. The first one, GIS-SAVER created by Michael Pawlovich, requires an ArcView license. The other, CMAT created by Dan Gieseman, is a MapObjects application that is licensed statewide. These new programs are part of a suite of tools to serve different needs and segments of the analysis community in Iowa.
Because presentation time is limited, only highlights will be included in the presentation itself. Ongoing developments with these tools can be obtained by visiting the Iowa DOT web site at http://www.dot.state.ia.us/crashanalysis/ after August 1, 2002.
Descriptions of these tools are given below. Following these sections, there is some background information about GIS development in Iowa authored by Joyce Emery, Program Manager, Iowa DOT Office of Traffic and Safety.
Geographic Information System-based Safety Analysis, Visualization, and Exploration Resource
(GIS-SAVER)
The Iowa DOT has had, for many years, PC-based Accident Location and Analysis (PC-ALAS and Access-ALAS) tools for the retrieval, query, and reporting of crash data. Over the past few years, the Iowa DOT has been developing GIS-SAVER (formerly called GIS-ALAS), which now enables retrieval, query, analysis, reporting, and visualization of a variety of safety-related information including crashes. GIS-SAVER presents a user-friendly interface to practitioners in the area of highway safety (e.g., engineering, enforcement, medical) to retrieve data pertinent to their needs.
GIS-SAVER consists of a series of dialog boxes, a number of scripts, and configuration files which facilitate the previously mentioned uses (retrieval, query, analysis, reporting, and visualization) and the updating of the system to fit changes in the data (e.g., a new crash reporting form). Previous analysis tools from the Iowa DOT 1) did not have mapping capability, 2) did not have or had limited visualization capabilities, and 3) did not include data beyond crash data. Additionally, GIS-SAVER allows local police using TraCS software to analyze their data on an immediate basis using the same tool as for statewide data that has been aggregated and released by the Iowa DOT.
Additional updates to GIS-SAVER include enhancing the user-interface, the analysis and visualization capabilities (by adding statistical analysis capabilities and charting/graphing), and the eventual broadening of SAVER to other GIS and non-GIS platforms (to provide low-cost alternatives).
GIS-SAVER is currently in alpha/early beta-testing and is slated to be released within the next couple months (July/August 2002). It will include 10 years of crash data (1991-2000) for the entire state of Iowa, along with background coverages (e.g., roads, rivers, rail, corporate limits). Please see http://www.iowasms.org/ under the "Data" link to view some of the data developed using GIS-SAVER.
Crash Mapping Analysis Tool
(CMAT)
Overview:
Iowa State University’s Center for Transportation Research and Education (CTRE) Crash Mapping and Analysis Tools (CMAT) is a software program that, when integrated with other analysis software, facilitates the graphical selection of geographically referenced events and incidents. The Iowa DOT commissioned CMAT so that older analysis tools based on the link-node system, used by hundreds of persons statewide, could continue to be used once the state converted to a coordinates location system. CMAT has done far more than just solve that problem.
CMAT uses a variety of tools to find event locations such as vehicular crashes, crime events, etc. By using such functions as: Point Select, Rectangle Select, Polygon Select, Route Segment Select, Intersection Select, City Select, and County Select a user has a wide variety of options for obtaining event information. An inset map allows the user to stay oriented during the selection (query) process.
Additional functions allow the user to change the color of CMAT features or labels (cities, counties, rivers, lakes, roads, mileposts, crash locations, etc.); to change the default distance units or distance from an intersection or a search point; to turn labels (county names, city names, road names, etc.) on or off; to select one or more specific years of crash data; to save, load, or delete queries; and to find a specific city or county.
An optional six-year histogram (vertical bar chart) is automatically created at the end of each query showing the number of crashes for each of the six years. This chart may be given a custom title by the user and printed as a separate report.
Interface With Access-ALAS:
If more than a CMAT summary trend report is desired, a query can be exported to Access-ALAS, the Iowa Department of Transportation’s non-GIS crash analysis software for in-depth analysis (day of the week, time of day, type of crash, major cause, etc.). CMAT permits a seamless query process for merging years of data located with both location systems. No modifications to the Access-ALAS software were required.
Applications:
CMAT allows the user to prepare, in a few seconds, a multi-year vertical bar graph with yearly totals as well as a grand total for all selected years and a two line custom title. The map area of the selected crashes along with the crash “dots” can also be printed.
Distribution and Future Plans:
CMAT has been in the hands of about 30 local agency beta testers for some months, and distribution beyond this group will begin in July 2002. This software essentially frees Iowa crash data users from the most time-consuming part of the analysis process: looking up and entering 8-digit node numbers. The “node map CDROM” will no longer be needed. (For ease of historical correlations, before and after studies, etc, the node numbers remain available on the CMAT CDROM.)
Plans are to replace the aging Access-ALAS software in a year or so, while retaining the CMAT “front end”. Iowa is gradually moving in the direction of consolidating its suite of analysis tools both for customer convenience and for easier maintenance.
History of GIS analysis development in Iowa
Joyce Emery
The first strategic plan of the Statewide Traffic Records Advisory Committee, completed in 1995, recommended to the responsible DOT offices that the current program of crash data availability be modernized and that more timely data be provided. The DOT responded by organizing a quality improvement team to review the existing crash analysis software, PC-ALAS.
Both the STRAC strategic plan and the DOT internal quality team called for investigation into the use of Geographic Information Systems as the future way of doing business. The first contract to begin the transition to GIS was initiated in January 1997 with the Iowa State University Center for Transportation Research and Education. Michael Pawlovich was the CTRE graduate student who undertook the development.
The first version of “GIS-ALAS” was field-tested in 30 state and local agencies with a 10-year crash data set ending with 1998 data. To our consternation, even our most enthusiastic customers were slow to try it out. It required ArcView running in the background, plus some general GIS know-how. The project was at the stage where customer usage was critical to future refinement. Without their input, little more could be done. We realized that the very novelty of it was a barrier for busy people. Our staff took up other urgent data projects, intending to get back to GIS-ALAS later on.
During this gap, GIS work went forward in other contexts. The Location Tool (smart map) for capture of coordinates was developed and implemented statewide. A MapObjects enhancement (Crash Mapping and Analysis Tools, or CMAT) to the non-GIS analysis tool was developed as a spin-off of the Location Tool. The Emergency Response Information System (ERIS) was also developed in this time interval. So, while we did not have a GIS analysis package that non-experts could use, we found ourselves with an array of other applications of GIS technology.
In this development interval, GIS analysis of crash data continued to be performed by GIS experts at Iowa DOT and at Iowa State University, and by a few others around the state. To help get GIS output and maps into non-technical customers’ hands, the Iowa Traffic Safety Data Service was set up through the Statewide Traffic Records Advisory Committee using Section 411 funding. Therefore, GIS analysis never ceased during the “gap” and continued to whet the appetite of customers.
When the GIS-ALAS development work was resumed, we had two new advantages. First, the original developer, Michael Pawlovich, had come to work for DOT from CTRE. Second, the rapid implementation of the Location Tool meant that the old analysis tools were out of date and that the time for GIS analysis “by the masses” had come. Furthermore, an analysis tool that could be used by local agencies for local TraCS databases was urgently needed—and GIS-ALAS was poised to fill that need.
Finally our ancient acronym “ALAS,” for Accident Location and Analysis System, seemed inadequate. Our suite of tools pertained to many more kinds of data than crash data, and to many more functions than analysis. A new name, GIS-SAVER (GIS-based Safety Analysis, Visualization, and Exploration Resource) is now in use and seems to be catching on.