WASHINGTON (AP) – Cars and motorcycles crash into deer more than 4,000 times a day, and it’s taking an increasingly deadly toll – on people.

Last year a record 210 motorists were killed in collisions with animals, mostly deer. That was 40 more than the previous year and more than twice the number in 1993, according to a study by the Insurance Institute for Highway Safety

Accidents are most likely to happen in November, the institute said, because hunters are out and deer are in the middle of their mating season, both of which cause the animals to be on the move. Crashes are most likely to occur during evening or nighttime, often on rural roads with speed limits of 55 mph or higher.

“The deer population is growing and there are more vehicles on the road every year,” Allan Williams, the institute’s chief scientist, said Wednesday. “There’s just a lot more chance for interaction with animals on the roads.”

Deer are involved in about 75 percent of fatal animal-crash accidents. In all, there were 1.5 million deer crashes last year, injuring 13,713 people and causing $1.1 billion in vehicle damage, the institute said.

The study found most animal crashes involved one vehicle and deaths usually were caused when the vehicle left the road or a motorcyclist fell off the bike. In relatively few cases, people were killed when the animal crashed through the windshield.

Other animals that cause crashes include horses, moose, dogs, bears, cats and opossums, though none is responsible for a significant number. Cattle also cause a small percentage of crashes, particularly in Western states.

Such animal-involved fatal crashes have been rising since the mid-1990s, according to federal data analyzed by the institute. Between 1993 and 1997, an average of 119 fatal crashes occurred each year. Between 1998 and 2002, the figure rose to 155.

The institute said special signs during migratory periods, thinning herds and signs that activate when deer are near roadways have shown promise in reducing crashes. Drivers also should be alert and slow down in the evenings, Williams said.

But even with precautions some crashes are unavoidable.

“Sometimes animals just appear in the roadway and there’s not much chance to react,” Williams said.

Motorcyclists are particularly vulnerable, especially when the rider fails to wear a helmet. In the institute’s analysis of fatal crashes in nine states, 65 percent of the 60 motorcyclists and all-terrain vehicle riders killed weren’t wearing helmets.

“If an animal hits a motorcycle, the motorcyclist can go off the bike pretty easily,” Williams said.

Of the nine states studied, only Georgia, Missouri and North Carolina require helmets for all riders. Minnesota, Ohio, Pennsylvania, South Carolina and Wisconsin require helmets for teenagers, but not adults, and Colorado doesn’t require helmets.

The same study found 60 percent of the 93 vehicle occupants killed in animal crashes weren’t wearing seat belts.