The details of every fender-bender and serious collision could fill a book on how people drive and the unsafe conditions that may exist at accident sites, but too often no one is stringing the chapters together.
Accident data are frequently incomplete or scattered in paper files, making it difficult to retrieve information and analyze it to spot trends quickly, before traffic deaths and injuries pile up.
But now, there is a drive to improve the way accident data are collected, categorized and interpreted to obtain more reliable information about the cause of traffic accidents and how to prevent many of them.
The city of Chicago and the Illinois Department of Transportation are building computerized databases to generate higher-quality crash information that will be used to engineer roadway, pedestrian-safety and traffic-flow improvements and to spend money where it is needed the most.
Federal funding to Illinois for transportation safety improvements has more than doubled from $21.6 million in fiscal 2003 to $49.1 million in fiscal 2006, according to IDOT. The federal money can be used for a wide variety of improvements, ranging from pavement rumble strips to gates at railroad grade crossings, with the goal of reducing deaths and serious injuries.
“We will sift through the data in much more flexible ways, focusing first on intersections, which are the hot spot for pedestrian and bicyclist accidents and injuries,” said Cheri Heramb, acting commissioner of the Chicago Department of Transportation.
The desktop technology will use filters to isolate or combine various factors and traffic conditions, depending on the type of analysis performed, officials said. The results can be presented in spreadsheets or in graphs.
For example, crash rates can be compared at specific locations based on whether the pavement is wet or dry, whether it’s day or night or whether it is a rear-end or angle crash. Dozens of other parameters appear as checklists or fill-in-the-blank sections of standard police accident report forms.
The new system is expected to be running next year. Currently, five years of accident data are being entered into the system, and the computer program is being refined, officials said. More data added to the system over the years will add depth and texture to the information, the officials said.
“It really is providing a different cut from the data to get to the root cause of the safety problems at each location,” said Christopher Wuellner, project development manager at CDOT.
The program is seen as a major improvement over the labor-intensive paper shuffling that Chicago officials now perform to come up with an annual report titled “Top 100 High Crash Intersections.”
It is so much work that the most recent report published is based on 2004 data.
The city relies on the data, rough as they sometimes are, to decide where to deploy red-light violation cameras and other traffic-calming devices that range from speed bumps to stop lights to traffic circles.
Red-light cameras are expected to be in place at 50 Chicago intersections by the end of the year and 280 intersections by 2010.
