The Development of a GIS-Based Crash Location Tool

Background and Project Statement

  1. The National Model, the Officer Information Manager, and the Mobile Accident Reporting System
  2. The National Model is a statewide effort to apply new technologies and techniques to improve Iowa’s highway safety data collection and management. A key component of the National Model is the development of the Officer Information Manager (OIM), which automates the completion of driver and vehicle related reports by law enforcement officers in the field using pen-based computers. Software has been developed for OIM to provide the computer interface through which crash information is recorded. This software, the Mobile Accident Reporting System (MARS), supports the link-node location of crashes that has been historically used in Iowa. It is designed to support the development of GPS technologies to locate accidents. Despite the success of the National Model, OIM, and MARS, much work remains to be done to collect crash data in a systematic, integrated manner throughout the state. Existing technologies must be further implemented and new technologies must be created to promote the seamless integration of data collection and management processes.

  3. The Accident Location and Analysis System
  4. Iowa’s efforts in safety data collection and management have been closely tied to its efforts in data access and analysis, as illustrated by the development and use of the Accident Location and Analysis System (ALAS). The ALAS effort stemmed from a widespread desire to create a user-friendly, fast, portable, system for accident data retrieval and analysis that could be used by a variety of clients, including the Iowa Department of Transportation (DOT), county and city engineers, municipal planning organizations, regional planning affiliations, law enforcement agencies, the Iowa Department of Public Safety, and the Iowa Office of the Federal Highway Administration. The first tool developed in the ALAS effort, PC-ALAS has been well received by users. Agencies can use the system to obtain accident statistics for specific locations and time periods, to query the database by crash or driver characteristics, and to generate reports to be sent to the screen, to a file, or to a printer. However, the DOS-based nature of PC-ALAS requires the use of node tables or paper maps, requires the manual entry of node numbers, and hinders the spatial analysis of accident patterns, the identification of crash "hot spots" and countermeasures, and the integration of additional types of data.

  5. Geographic Information Systems – Accident Location and Analysis System (GIS-ALAS)
  6. Iowa’s relative success in crash data collection, particularly in providing a location reference for every crash in the state, has facilitated the development of GIS-ALAS by the Center for Transportation Research and Education (CTRE) on behalf of the Iowa DOT. GIS-ALAS is being developed to address the above difficulties associated with the use of PC-ALAS. In the Year 1997 effort (Phase I of a three-year sequence), GIS-ALAS was constructed to reproduce the current functionality of PC-ALAS and, moreover, to incorporate the powerful spatial query and display capabilities of GIS. The graphical interface of GIS-ALAS allows the viewer to see on-screen maps of accident locations and to select specific nodes and links of interest with the click of a mouse. Paper maps and tables of node numbers are unnecessary, as is the manual typing of node numbers to do queries. The results of GIS-ALAS queries can be displayed, not only in tabular form but also in maps.

    Phase 2 of the GIS-ALAS effort focuses on extending the usefulness of system through the completion of several tasks, including: the refinement and enhancement of GIS-ALAS based on input from current users; the assessment of methods to identify accident rates for highway sections or intersections based on specific accident locations and traffic counts; the development of an enhanced procedure for link-node/latitude-longitude conversions; the analysis of changes in emergency response patterns due to the construction of the "Avenue of the Saints"; and the continuation of Technology Transfer activities, including training and documentation on the enhanced version of GIS-ALAS.

  7. The Potential Use of GIS in the Crash Data Collection Process

The development and progress of National Model has generated considerable interest in exploring additional efficiencies that could be exploited through the coordination of its various data-related activities, from collection to analysis.

The ALAS effort has benefited from Iowa’s longstanding effort to provide a location reference to crash data. The importance of data collection, in turn, is being made more apparent by advances in data analysis. Moreover, technologies, such as GIS, developed largely for analytical purposes, are showing promise in improving the efficiency and accuracy of data collection.

To explore these possibilities, several meetings have been held between members of the GIS-ALAS Advisory Committee, personnel from Office of Transportation Data in the Planning and Programming Division of the DOT, the Office of Driver Services in the Motor Vehicle Division, the DOT GIS Coordinator, and AMS (a consultant) regarding data quality, input, formatting, and conversion issues, and various related process improvements. Among other topics, discussions have focused on methods used to process crash information, including a location reference, and incorporate it into the crash database. This includes the possibility of "smart maps" to locate crashes.

The diagram on the next page (not available online) outlines the current and potential future flows of crash data in Iowa, from the initial collection of data to its incorporation into GIS-ALAS, PC-ALAS, and Access-ALAS. It is interpreted as follows. The green boxes represent existing entities or processes in this flow of data. The yellow boxes represent existing processes that would be improved if potential changes were implemented. The red boxes represented new processes. The solid lines represent existing connections between entities/processes, while dashed lined represent potential connections. Similarly, non-italicized text is used to describe the current situation, while italicized text is used to describe potential changes. Four potential process improvements are represented:

In this document, the Center for Transportation Research and Education proposes to address the first process improvement listed above, specifically the development of a GIS-based tool to be integrated into the MARS software, with which local agencies, as well as the Motor Vehicles Division, can locate crashes. This tool would use smart maps to allow the user to view a map on a computer screen and select the appropriate crash location with the mouse. The coordinates of this location would then be saved and linked to the other crash data collected. The tool would be available both in mobile applications (i.e., in police vehicles for use in the field) and in desktop use in an office setting. This would provide the required functionality for creating and providing crash reports, both to local agencies with the mobile application and to local agencies with only the desktop application, as well as to the Motor Vehicle Division.

CTRE proposes to develop this tool and provide for its implementation through undertaking the following tasks.

  1. Proposed Research Methodology

    2.1 Task 1. (15%): Research/Scoping (September)

    Task 1.A Review current crash data collection and management procedures in Iowa, emphasizing crash location

    The project team will review current methods used to locate crashes in Iowa. This review is intended to provide a starting point for assessing potential strategies for developing and implementing the GIS-based crash location tool. This review will include: a) current methods of recording information in the field, such as paper forms and computer-based input via MARS; b) data entry and management activities performed on desktop computers in local agency offices: c) the transfer of information from the local office to the DOT; d) data processing, conversion, and transfer processes performed by the DOT; e) the development of databases for use in PC-ALAS, Access-ALAS, and GIS-ALAS; f) the data formats and software packages used throughout the above process; and f) location referencing and location data collection methods, including the relevant conversions between these methods.

    Throughout this review, the focus will be on the implications of the above elements for the selection of appropriate strategies used to develop the GIS-based location tool. This will ensure that the tool will be compatible with existing and future data collection and management procedures, and that the efficiency of the entire process is improved.

    Task 1.B Identification of user requirements and preferences

    The project team will survey users and potential users to identify user requirements and preferences. The team will consider such aspects as software cost, learning curve, interface, integration with MARS, and other identified factors.

    Task 1.C Assessment of software development options/Selection of one option

    Several software development options will be assessed according to several criteria, including cost, compatibility with MARS and other existing OIM technologies, and ease of use. At a minimum, the project team will consider: a) a freeware GIS data viewer, ArcExplorer; b) a customizable desktop GIS package, ArcView; c) a GIS software designed for application development, MapObjects. Other options will be considered where appropriate.


    2.2 Task 2. (50%): Development of GIS-Based Crash Location Tool (September - December)

    A tool will be developed that can be used to identify the x,y location and the route ID for a crash.


    2.3 Task 3. (15%): Initial Testing/Refinement (October - November)

    The project team will provide a demonstration of the beta version of the location tool to the Division of Motor Vehicles and representatives from local agencies. Feedback generated from this demonstration will be used to identify necessary modifications before technology transfer activities.



    2.4 Task 4. (20%): Technology Transfer (December)

    Technology transfer activities will include: a) documentation of the development of the GIS-based crash location tool; b) a users guide to assist in training users; and c) a tutorial session.

  3. Project Products and Deliverables

Four main products will be delivered as part of this project.

Project Personnel

Principal Investigator: Reg Souleyrette, Associate Director for Transportation Planning and Information Systems at CTRE, Associate Professor of Civil and Construction Engineering at ISU.

Project Manager, Tim Strauss: Research Associate, CTRE.

Michael Pawlovich, Graduate Research Assistant, CTRE

Brad Estochen, Graduate Research Assistant, CTRE

Project Monitor

Terry Dillinger, Director, Office of Driver Services


CTRE is an Iowa State University center.

Address: 2711 S. Loop Drive, Suite 4700, Ames, IA 50010-8664

Phone: 515-294-8103
FAX: 515-294-0467

CTRE Communications: Marcia Brink
CTRE Webmaster: Michele Regenold


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