Mating season is underway for whitetailed deer, which means they are on the move and are more likely to dart into roadways and cause accidents.

According to new numbers from State Farm Insurance, an estimated one in 86 licensed drivers in Pennsylvania hit a deer in the year ending in June, making Keystone State drivers the fourth-most collision prone in the country.

The company urged drivers not to rely on the deer whistles some drivers mount on the front of their cars to prevent crashes.

Peter Scheifele, a University of Cincinnati professor, said there is no evidence the whistles work. He tested six different models, which emitted two different frequencies.

"One frequency was put out at a level that was not hearable by whitetailed deer," Scheifele said. "The other frequency, which was the higher of the two, was just at the level of detection of the deer, but probably would be masked out by traffic noise."

New Jersey officials are urging drivers to be alert, especially around dawn and dusk, when visibility is low and deer are most active. They are also asking drivers to pay attention to deer-crossing signs.

Michael Wade, a professor of kinesiology at the University of Minnesota, said drivers seem to ignore traditional roadside signs. He studied how people react to standard signs and those fitted with deer motion-detectors.

"With the standard signs, people went through at 65-plus," Wade said. "When we put the signs up which had the flashing beacon on the top of the sign, triggered by motion detection systems, people slowed down to 59."

According to State Farm, deer-car collisions were down last year for the third straight year, perhaps due to decreased driving due to the recession.

Pennsylvania drivers still had the most collisions—an estimated 100,000 run-ins with deer.