John Clawson is talking about his pickup truck and the question people always ask him when he is interrupted by a passer-by: "Hey, how do y'all get in that thing?"

That, says Clawson, is the question.

One glimpse of the Manassas construction worker's wine red 1984 Toyota pickup makes it clear why people ask about the truck.

Sitting atop 42-inch balloon-like Super Swamper tires and 20 inches of added suspension, Clawson's Toyota stands 8 feet 3 inches high, several feet above the typical Toyota.

"I like it tall," said Clawson's wife, Litisia, who is 5 feet 2 inches tall and seems little troubled by how she gets behind the wheel.

It is simple enough, she said. Put a foot on the front tire and a hand on the window frame for leverage and pull yourself up.

"Everybody stares and waves," said Litisia Clawson, who drives the truck every day. "It's an opening . . . people want to talk."

And, she said, there are practical advantages: "I can see an ambulance coming before anybody."

To the consternation of Virginia motor vehicle authorities, the Clawsons are not the only ones riding high these days. A growing number of Virginia motorists, usually aged 19 to 26, are driving around in four-wheel-drive trucks that have been "lifted" by special high suspension kits and oversized tires.

That worries state officials and others who say that the high riders are dangerous, often so high that they easily plow over other cars in collisions, causing greater injury and damage than accidents involving conventional trucks.

"We think that they are unsafe," said Clarence Ditlow, executive director of the Center for Auto Safety in Washington, an organization founded by consumer advocate Ralph Nader. "There have been a number of reports of people who have been killed or injured by these high riders."

His organization, citing its concerns, has urged the Department of Transportation to regulate bumper heights.

Virginia State Trooper Larry Lam, who is part of a state task force studying the vehicles, said they have a higher center of gravity and therefore a greater tendency to roll over in accidents.

Other problems include blind spots and greater exposure of gasoline tanks to puncture. "It's hard to see the vehicle in front of you or to the side," Lam said.

Virginia Beach authorities tried during the summer to bar the trucks from the resort strip, using a city ordinance that declared them unsafe. City Councilman H. Jack Jennings led the fight against the vehicles, saying their front lights were so high that they often would blind other motorists whose rear view mirrors are set for conventional automobiles.

A city judge, however, threw out the law, to the delight of hundreds of high riders. Virginia law, the judge noted, says that passenger vehicles cannot be higher than 22 inches from the ground, nor lower than 14 inches. But trucks are not considered passenger vehicles under state law.

Virginia law does prohibit the use of lift blocks to modify front-end suspension, Trooper Lam said. But, he noted, there are no real regulations, no height limit and no rules on tires.

Until July, high riders in Maryland were able to get around a law prohibiting vehicles with bumpers higher than 28 inches by declaring the trucks multipurpose vehicles, according to Steve Horwitz, a spokesman for the Maryland Motor Vehicle Administration.

The legislature closed that loophole, giving the trucks an 18-month grace period to come into compliance.

"It was quite a problem," said Capt. Richard Janney of the Maryland state police, but "it's died down since July 1."

The District maintains restrictions on vehicles' width and height but not on bumper heights, said Lt. William White III, a police spokesman. Any vehicle that is determined to be modified to such a degree that it is in an "unsafe condition" can be impounded, he said.

The Clawsons, both 24, express no concern about safety and sing the joys of riding high. They say they get a lot of mileage out of their truck, take it to off-road-truck shows, help hospital workers get through the snow and compete in mud races.

The high riders, usually Toyotas, and the bigger model trucks, typically Fords, are not cheap to convert, said Clawson, who said his truck is worth $13,000 to $14,000.

Fred Young, a mechanic at JJs, a truck shop in Fairfax, said one tire with rim can cost about $350 and a suspension kit about $300. With the typical accessories, such as a row of five lights on the roof for $250 and a chrome roll bar for $300, labor can total $360, he said. Not to mention the cost of the basic truck, currently $10,000 to $12,000.

"It's a fad at this point," said Young. "It's different . . . flashy. You go down to Georgetown and you'll see 'em cruising up M Street.

"All this shouts: 'Look at me. I've got five lights, chrome roll bar, fancy paint, big wheels.' "

Young said most people have the trucks for show. "There's not much off-road here," he said. "Unfortunately, those who have them for off-road have to go on the road to get there."

Trooper Lam said no one knows how many high-rise vehicles are registered in Virginia. "Right now, when they register them they don't say if they're high-rise," he said.

For now, at least, the Clawsons plan to keep on trucking. But if one of their $300 tires perchance goes flat, John Clawson has another idea: "We'll walk."