The number of people killed on Ohio roads increased in 2012 compared with 2011, even as the State Highway Patrol made thousands of stops for drug violations, impaired driving and other problems.

The patrol reported at least 1,056 deaths in 962 fatal crashes during the past year, up from 1,015 deaths in 2011, which was the lowest total since record-keeping began in 1936. Hamilton, Mercer, Trumbull and Warren counties each had at least 10 more traffic fatalities in 2012 than in the previous year, according to preliminary data.

Patrol spokeswoman Lt. Anne Ralston said it's too soon to understand the reasons for the increase in deaths, though she noted that an increase during the first half of the year reflected a similar trend at the national level.

Ohio also has at least 45 unconfirmed crash fatalities, which include those that remain under investigation and may not ultimately be ruled traffic deaths. That makes the potential total about 1,100 fatalities for the year. The final number, to be released later after ongoing investigations wrap up, is likely to fall somewhere between the number of confirmed deaths and the possible total.

"If one person is dying on our roadways, we still have work to do," Ralston said. Compared with 2011, troopers made about 1,500 more arrests for drug violations and over 800 more arrests for impaired driving in 2012, according to preliminary data. They also issued about 7,500 more citations for seat belt use and used three regional squads to specifically target crash-causing violations.

Col. John Born, the patrol's superintendent, said the agency was "seeing positive results" from troopers' work to get dangerous drivers off the roads.

Hoping to lower the number of traffic fatalities below 1,000, the patrol this year plans to continue its focus on impaired driving and high-visibility enforcement efforts, such as checkpoints targeting impaired drivers and "All-Out" days that send all its officers on patrol for a day.

Ohio also plans to steps up its investigations into the source of drugs or alcohol suspected of causing serious wrecks. Troopers will aim to identify impaired drivers, and state investigative agents will be looking for possible criminal violations stemming from the source of the drugs or alcohol involved.

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