Northeastern Illinois Safety Data and Analysis

Regional Performance Measurement: Highway Traffic Safety Data Overview

New!  Highway Traffic Safety Data Overview for Metropolitan Chicago. This analysis, as reported by Jon Hilkevitch's Getting Around column in the Chicago Tribune, provides an overview of highway traffic safety trends in the Chicago region.  The report shows substantial reductions in fatalities and serious injuries since 2002. 

The causes of motor vehicle crashes are complex, owing to interactions between vehicles, roadways, and driver behavior.  However, the report demonstrates that concerted efforts to improve vehicles' ability to avoid crashes, vehicles' crashworthiness, driver training and compliance with traffic safety laws, and highway safety engineering focused on addressing locations with high rates of fatal and serious injury crashes have, together, had a strong positive effect over the past several years.

Supplementary Information: Highway Safety Improvement Strategies:  To address highway safety, communities and highway agencies have engaged in a number of strategies to reduce crashes.  Implementation of some strategies is just beginning, or may even be experimental, while other strategies may be fully implemented.  A definitive Highway Safety Manual is now being published (July 2010) by the American Association of State Highway and Transportation Officials (see item below).  Here are a few resources on improving highway safety, including information on proven strategies.  Several of the strategies listed in the resources below were highlighted by Jon Hilkevitch of the Chicago Tribune in his Getting Around column.  Note that the implementation of all strategies is subject to further study of a particular proposed improvment site, evaluation of detailed crash information, and engineering judgment.  Various vendors and technologies to implement the strategies may have specific strengths and weaknesses that must be evaluated by implementing agencies.  Further, none of the strategies is a substitute for traveling with care while on the road, and taking necessary precautions like wearing a safety belt and avoiding driver distractions.

- Federal Highway Administration: Guidance Memorandum on Consideration and Implementation of Proven Safety Countermeasures: This policy document provides a brief analysis of nine proven safety countermeasures, indicating when and where these countermeasures should be used.  The countermeasures include Road Safety Audits, Rumble Strips/Stripes, Median Barriers, Safety Edge, Roundabouts, Left and Right Turn Lanes at Stop-Controlled Intersections, Yellow Change Intervals, Medians and Pedestrian Refuge Areas in Urban and Suburban Areas, and Walkways. 

- Federal Highway Administration: FHWA Safety Program:  In addition to the brief document above, FHWA maintains information related to its reseach, program support, and promotion of many strategies to address safety.  These include intersection safety, local and rural road safety, pedestrian and bicycle safety, roadway departure safety, speed management, and additional initiatives. 

As part of its strategy research for GO TO 2040, CMAP also studied the following strategies with positive implications for highway safety:

-  Roundabouts (strategy paper) (see also the July, 2010 FHWA video on roundabouts, posted on the FHWA roundabout page).

-  Access Management (strategy paper)

Of course, crashes are directly related to driving, and can be reduced by implementing proven travel demand management strategies (strategy paper). More broadly, implementing many of the recommendations of the draft GO TO 2040 Regional Comprehensive Plan will also reduce travel demand, by encouraging the development of more compact, walkable communities. 

Motor Vehicle Crashes with Bicycles and Pedestrians

CMAP maintains a separate web page with data and maps related to walking and cycling safety.  The data and maps are posted here.  

Highway Safety Manual

Expected, July 2010:  The Highway Safety Manual (HSM) should soon be published by the American Association of State Highway and Transportation Officals (AASHTO) after a decade of research and analysis by AASHTO, the Federal Highway Administration, and the Transportation Research Board.  The Manual will help measurably reduce the frequency and severity of crashes on roadways by providing tools for analyzing safety impacts in the during highway project development. The Manual will assist engineers and planners in selecting countermeasures and prioritizing projects, and comparing alternatives. According to AASHTO, the Highway Safety Manual "will present information on roadway safety fundamentals, the safety management process, models for estimating the expected safety performance of a specific facility, and crash modification factors for estimating the expected effectiveness of individual infrastructure-based countermeasures. "  For more information about the manual, see http://www.highwaysafetymanual.org/Pages/default.aspx.  The manual is available to purchase from either AASHTO or the Institute of Transportation Engineers.

Community Safety Approach

CMAP strongly encourages northeastern Illinois to take a community approach to addressing highway safety that uses the best data and analysis combined with local knowledge of traffic conditions to reduce crashes.  This approach can result in safety improvements by strategically looking at traffic patterns in a corridor or neighborhood to address traffic crashes, identifying ways not only to reduce crash risk, but the exposure to risk as well.  Sometimes, a solution to a crash problem at one location may be a few blocks or more away.  

Presentation to Council of Mayors (pdf, 1MB) February 5, 2008

Detailed Analyses for Engineers and Planners 

Intersection Crash Analyses

Intersection Crash Analyses, Years 2005-2006.  (Revised December 22, 2008) This report examines high-crash locations in 2005-2006 in metropolitan Chicago that contain intersections.  The goal of the report is to identify intersections that have high crash frequencies or high crash rates for specific types of crashes.  Determining where specific types of collisions occur will allow safety funds to be invested where they may be of the highest benefit. 

Regional Crash Maps

The maps below are technical maps of crash locations and crash concentrations within Metropolitan Chicago.  These data represent one among many resources that may be used by engineers and planners to identify sites that might bear further analysis of crash information.  The data are not definitive in identifying hazards, since they do not control for volumes at intersections or highway segments.  Furthermore, any hazard identification should include a review of original crash records by professional personnel.  However, the crash data may be an information tool to use to begin a community process of improving highway safety where concentrations of crashes and casualties are identified.

The most serious cost of crashes is the human toll in casualties - injuries and deaths.  Thus, most of the maps below are focused on identifying the sites of fatalities and serious injuries.  However, less serious crashes also have a price in property damage and delay.  Therefore, that information is also available (via our ftp site because of the file size).

Instructions for using these maps are provided and should be read before trying to open the maps.  The maps are technical in nature, with many layers that can be opened and closed, and are best used at highly zoomed-in levels (800-2400%). 

Map of All Regional Crashes 

A regional map of all crashes in 2005-2006 (pdf, 46MB) is posted to the CMAP FTP site.  Access the map with username "cmapftpro" and password "cmapread".  Right-click on the posted file entitled safety_allcrashes_yrs0506_20080208.pdf, then select "Save As" to your computer.  Note: The map includes several hundred thousand crashes, so opening this file takes some time on even fast computers. 

Maps of 2005-2006 Metropolitan Chicago Fatal and Serious Injury Crashes

All Fatal and Serious Injury Crashes (pdf, 12MB)

Overturned Vehicle Crashes (pdf, 10MB)

Head-on Crashes (pdf, 10MB)

Angle Crashes (pdf, 10MB)

Side-Swipe Crashes - Opposite Direction (pdf, 10MB)

Side-Swipe Crashes - Same Direction (pdf, 10MB)

Parked Vehicle Crashes (pdf, 10MB)

Semitractor-Trailer Crashes (pdf, 9MB)

Motorcycle Crashes (pdf, 10MB)

Late Night Crashes (pdf, 10MB)

Speed-Related Crashes (pdf, 10MB)

Vehicle Turning Crashes (pdf, 10MB)