Fauquier County farmer Rick MacWelch is used to the car and truck crashes along the curve of Rte. 17 that borders his pasture, but one wreck three weeks ago still shakes him.

Minutes after he reached the small car on the side of the road, he discovered that the four local women in it were dead. A truck driver, whose tractor trailer had collided with the car, staggered out of his rig in a daze.

"Basically that did it," said MacWelch. "It was the last straw."

The accident has spurred a citizen's movement to ban tractor trailers from that stretch of Rte. 17, a movement that has reached to the governor's office and is still growing.

Rte. 17 is a major route for vehicles traveling from the Pennsylvania Turnpike to I-95 in Fredericksburg, say state traffic officials. Local residents contend that the road has become a hideout for overweight trucks trying to avoid the weigh stations along interstates.

Most of Rte. 17 is a four-lane primary highway, but it narrows to two lanes between I-66 and Warrenton. It is from that curvy, 8.9 mile stretch of Rte. 17 that local residents want to ban trucks -- until the road is widened to four lanes.

Last summer the Virginia State Highway Commission voted to spend more than $8 million to widen the 8.9 miles of road in a project not scheduled for completion until after 1990, said Robert E. Moore, of the Virginia Department of Highways and Transportation's Warrenton office. He said the project has been broken down into four phases that will have two to three miles of the road widened at a time starting next spring.

Residents who have formed an active group called Safety on Seventeen say the large tractor trailers have to go. MacWelch said the group is circulating petitions calling on the governor to ban the trucks, install permanent truck weigh stations along Rte. 17 and widen the 8.9 mile stretch.

"It was the residents who got them to agree to widen the road," said MacWelch. He and his neighbors began petitioning for the widening project three years ago. "I'm confident we will get them to get rid of the tractor trailers as well."

Rte. 17 is wholly owned by the state of Virginia and the governor does have the authority to ban trucks along any or all of the road, said Moore. He said the state has banned trucks on roads in the past.

"There is a precedent," he said.

A spokeswoman from the office of Gov. Charles S. Robb said the governor has received 37 letters about trucks along Rte. 17 and would refer any petition he might receive to the State Highway Commission for study and a recommendation.

The commission has already requested a study of the number of accidents that have occurred along the stretch of Rte. 17 and the number of trucks involved, said Jon DuFresne, district traffic engineer for the Virginia Department of Highways and Transportation. He said the study is not yet completed and the figures are unavailable.

However, he said traffic along the 8.9 miles has risen from an average of 6,505 vehicles a day in 1980 to 7,528 vehicles a day in 1983.

"The increase especially has been in the tractor trailers," said MacWelch. "Everything that is oversized and overlinked is on this road. Half the time they're so wide their wheels are off the road, on the shoulder, cutting ruts a foot deep."

The Safety on Seventeen committee took out a full-page advertisement in the local Fauquier Democrat newspaper last week and will continue to circulate petitions to send to the governor, said MacWelch. He said the names on the petitions, which started making the rounds last week, have not been counted.

"People are calling us asking to be included," he said. "That last crash was the last one." The victims were three elderly women from Warrenton on their way back from shopping and a younger neighbor who was driving them home.

"We call it the Killer Highway now," he said.