James Bellard slammed on his tractor-trailer's brakes as a 4-foot chunk of ice and snow from a passing car crashed into his cab's windshield.

"It was scary, that's for sure," Bellard, of Baton Rouge, La., said Friday, recalling the incident several years ago on Interstate 75 just south of Cincinnati.

"At first I thought it was going to hit my side of the windshield," Bellard said. Though he had to replace the windshield, Bellard wasn't injured.

Accounts like Bellard's are a common winter war story among truck drivers at the TravelCenters of America truck stop off Interstate 81 in Troutville. They're highlighted by a Wednesday incident in which state police said a trucker traveling on I-81 in Roanoke County was injured after several large pieces of ice from another truck smashed through his cab's windshield.

"We all see cars driving down the road with the bare minimum of snow cleared off," said Martha Meade, spokeswoman for AAA Mid-Atlantic. "It's inexcusable."

Snow and ice left on vehicle roofs can fly backward onto other motorists at speeds of more than 70 miles per hour, Meade said, creating a missile of sorts with the potential to cause injury and damage. She pointed out that it's not just a danger for others; melting snow can slide onto the driver's windshield, blinding his or her view of the road.

Despite the potential risks, Virginia has no law requiring drivers -- of passenger vehicles or tractor-trailers -- to clear snow and ice before driving.

"Common sense tells you it's not a good idea," Virginia State Police spokesman Sgt. Rob Carpentieri said.

States such as New Jersey and Pennsylvania require drivers to make "reasonable efforts" to remove the wintry collections from any surface of a vehicle or risk a fine. Additional fines can be added if falling snow or ice causes injury or damage.

Carpentieri said cases such as the one Wednesday are civil matters that are often resolved between insurance companies. And that's if the vehicle throwing the snow even stops.

James Henderson, a trucker from Williamsburg, Ky., who often drives Virginia's interstates, said there should "absolutely" be a law that requires drivers to clear snow and ice from their vehicles. But Henderson noted that it's difficult for truckers to clear their trailers, most of which are legally required to stand 13.5 feet high.

"How are you going to get up there and do it?" he said. "I don't carry a ladder and stuff with me. I don't have no way of getting [snow] off."

Henderson said many trailer roofs would not even support the weight of someone standing on top.

Meade and Carpentieri suggested drivers traveling behind a vehicle topped by snow or ice slow down or move to another lane. Both stressed that even without a law requiring it, motorists should clear surfaces and windows before driving.

"I think motorists have an obligation to the safety of themselves ... and all the motorists on the roadways," Meade said.