toledoblade.com --

Imagine the lives that could be saved if you could predict where and when traffic accidents will occur.

The Ohio Highway Patrol took a big step in that direction recently with the implementation of an elaborate statistical modeling system.

Developed for the state patrol by the Ohio State University Statistical Consulting Service, the system calculated where the highest-risk areas were for serious crashes on selected freeways in Toledo and four other metropolitan areas statewide.

In the past, Ohio's state troopers relied almost exclusively on experience - theirs and their supervisors' - to determine where patrol efforts might do the most good to promote highway safety.

"Troopers traditionally have a good idea where crashes have occurred," Lt. Rick Zwayer, an OHP spokesman said. "But this model flags certain areas, times, and even days."

With that information, Lieutenant Zwayer said, troopers can focus traffic enforcement efforts on areas with the highest potential for or frequency of accidents.

On a page at its Web site, the OHP is also mapping fatal-crash locations statewide on Google Earth's satellite pictures of the state. The public can access data for 2005 fatal crashes statewide, with point-and-click computer access allowing viewers to call a pop-up box providing a brief synopsis of each crash. Computer-screen icons identify crashes by auto, motorcycle, and commercial vehicles and whether alcohol was a factor in the crash.

"We can look for patterns there too," said Lt. Robin Schmutz, commander of the highway patrol's Toledo post. "Lately, we've seen a pattern of motorcycle fatalities in Lucas and Fulton counties, and this allows us to pay special attention to motorcyclists and also discuss motorcycle awareness with motorists we contact."

The statistical crash-prediction model created by Ohio State used statewide crash data from 2001 through 2005 to develop histories for sections of the interstate in the Toledo, Cleveland, Columbus, Cincinnati, and Dayton metro areas. It then prepared forecasts for June 30 - the beginning of the travel period for the Independence Day holiday - for certain freeways selected by the highway patrol, including I-280 and I-475 in Toledo.

The highway patrol is not targeting I-75 right now, nor is it targeting all freeways in the other metro areas, but the model's geographic coverage could expand in the future as the program advances, Lieutenant Zwayer said.

Crunching the numbers produced some forecasts that to most troopers and even the general public probably seem intuitive, such as:

Alcohol-related crashes are most common in the evening.

Overall crash numbers are highest during the afternoon rush hour.

Crash rates increase in bad weather.

But statewide, the analysis revealed a few previously unknown patterns, said Christopher Holloman, the Ohio State consulting service's director.

Most notable, he said, are spikes in crashes involving commercial vehicles on Friday afternoons and in alcohol-related crashes during the wee hours of Fridays or other days just before holiday weekends - such as early on Thursday if Friday is a holiday.

"Those alcohol-related crash periods actually go much later into the morning than was previously recognized," Mr. Holloman said.

In developing the statistical model, Mr. Holloman's agency entered fatal and injury crash records from January, 2001, through June, 2005, then used July through December, 2005, data as a "control" to check the accuracy of predictions the model made for that period based on the earlier records.

The results showed that while pinpoint forecasts could not be made for specific dates and times at a given location, over the long haul the model is accurate enough to justify directing patrols to certain stretches of highway during certain high-risk periods, Mr. Holloman said.

Lieutenant Schmutz, who on June 30 assigned extra patrols to sections of I-475/U.S. 23 identified by the model's forecast, said the Toledo post handled just one noninjury crash on that freeway during the entire holiday weekend.

"If you look at it, we were successful" in preventing more serious accidents, he said.

Mr. Holloman said he was not aware until informed by The Blade that I-280 has been closed since mid-October for construction in North Toledo, a closing for which the posted detour directs through traffic away from that freeway except for its southernmost two miles in Lake Township. The detour could certainly explain why crashes on I-280 between July and December were lower than the model predicted, he said.

The model also assumed that when a holiday like Independence Day, Christmas, or New Year's Day falls on a weekend, the public holiday is always moved to Monday, when, in practice, a Friday is assigned if the holiday falls on Saturday.

Mr. Holloman said future revisions could be made to the model to reflect that practice, but he did not consider it to have a significant impact for now. Between 2001 and 2005, Christmas and New Year's fell on Saturday in 2004, but Independence Day did not.

While the forecasting model covers injury accidents as well as fatal crashes, the online mapping capability applies only to fatalities.

Even so, Lieutenant Zwayer said, "it gives a visual idea where certain types of crashes are occurring," both for the patrol's internal planning purposes and for public awareness.

As further technological advances occur, he said, the highway patrol will likely include more and more information with the mapping system that the public can access online.

Right now, for example, the system states whether alcohol was a factor in a truck or motorcycle crash but, in a multi-vehicle crash, does not identify which driver was found at fault. In the future, Lieutenant Zwayer said, the system could even provide a direct link to complete police crash reports, including scene photographs.

"There's a lot of informational possibilities out there with technology," he said.

Contact David Patch at: dpatch@theblade.com or 419-724-6094.

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