DANVILLE – It's illegal in Illinois to talk on a cell phone in a construction zone, but every driver pulled over for that offense in a recent traffic detail had no idea the law existed.

"I see that pretty routinely on the road," Vermilion County Sheriff Pat Hartshorn said of drivers using cell phones. "It appears to me that about every other car, someone is involved in a conversation (on a cell phone)."

Driver distraction is thought to be the cause of nearly 80 percent of automobile accidents in the U.S., resulting in about 2,600 deaths, 330,000 injuries and 1.5 million instances of property damage annually, according to a published study by Sheldon H. Jacobson, a UI computer science professor who has researched the impact of cell phone legislation on driving safety.

Jacobson's research shows that cell phone bans in more densely populated areas can reduce the rate of fatal and personal injury accidents.

In New York state, 46 counties had lower fatal accident rates after a cell phone ban was implemented in 2001, and all 62 counties experienced lower personal injury accident rates, according to Jacobson's research, which analyzed data from five years before the ban and the years after.

According to his study, every state has considered cell phone ban legislation since 1999, but as of 2008, only six states and the District of Columbia have laws banning hand-held cell phones while driving.

Jacobson said other research suggests that in laboratory settings, hand-held cell-phone use impairs driver performance by increasing tension, delaying reaction time and decreasing awareness, but there is insufficient evidence to prove that it increases the risk of automobile accidents.

And that's what Jacobson intended to investigate with his research in New York.

He said cell phone bans are controversial, because there are freedom issues at stake, and those for and against cell phone bans have good arguments.

Still, in the highly congested New York counties where there are 9,000 to 30,000 licensed drivers per square mile, there was a precipitous drop in the rate of fatal accidents after the cell phone ban took effect.

"When you look at counties that are less dense, we stopped seeing this effect" for fatal accidents, Jacobson said, but for personal injury accidents, there was a significant drop even in the less dense counties.

In New York counties with 100 licensed drivers per square mile or more, which would be the same density as Champaign County, there was a statistically significant drop in personal injury accidents after the ban, according to the study.

"So (Champaign County) is in the group that is highly likely a ban would reduce the number of personal injury accidents," Jacobson said.

Jacobson emphasizes in his study that although a ban on hand-held cell phone use in rural areas has less of an impact on driver safety, it doesn't necessarily mean a ban is worthless.

"It just means that such legislation is less likely to have an impact on driver accident rates," he states in the study. "If you have a lower congestion of cars, you're still distracted, but you're less likely to hit anyone, because there are less people to hit. It's simple probability."

Almost two weeks ago, a highway construction crew on U.S. 150 west of Danville alerted Vermilion County sheriff's deputies that a lot of drivers had been spotted in the zone talking on cell phones.

Hartshorn said deputies set up an enforcement detail. And 50 percent of the drivers observed during that operation were talking on cell phones, and all those who were stopped were not aware of the state law prohibiting cell phone use in construction and school zones, Hartshorn said.

"In a work zone or school zone, there's such a large opportunity for an accident," he said.

"People need to be concentrating as much as possible when they go through those areas."

Illinois law makes exceptions for people dialing 911 for an emergency.