Large trucks — Utah Permit Test

71% of fatal crashes involving a truck and another vehicle are caused by the other vehicle, usually a car.

Seven in ten of these crashes are the car driver’s doing, which is the opposite of what most drivers assume.

According to the National Highway and Traffic Safety Administration (NHTSA), 71% of fatal crashes involving two or more vehicles, one of which is a truck, are caused by another vehicle, usually a car.

An average passenger car traveling at 55 mph can stop in about 130 to 140 feet, while a fully loaded tractor-trailer may take more than 400 feet.

Three times the distance. Pulling into that gap in front of a truck removes the space it needs to stop at all.

A fully loaded tractor-trailer may take more than 400 feet to come to a complete stop or one-third more than the length of a football field.

A driver should always pass a tractor-trailer completely and on the left side, and should not linger alongside it.

Sitting beside a truck leaves the driver nowhere to swerve if something appears in the road ahead of them.

Always pass a tractor-trailer completely and always on the left side.

Large vehicles sometimes swing wide to the left to clear a curb on a right turn, so a driver should not turn until the vehicle has finished its turn.

A truck swinging left is starting a right turn. Filling the gap it leaves is how a car ends up under the trailer.

Large vehicles sometimes swing wide to the left to clear a curb on a right turn.

Cutting into the open space in front of a truck removes the truck driver’s cushion of safety, and trying to beat a truck to a single-lane construction zone is particularly dangerous.

That gap is not spare road. It is the distance the truck needs to stop, and it takes a few seconds to rebuild.

Cutting into the open space in front of a truck removes the truck driver’s cushion of safety.

A driver should never underestimate the size and speed of an approaching tractor-trailer, because its large size makes it appear to be traveling slower than it is.

A big object seems to move slowly. Many car and truck crashes at intersections come from exactly that illusion.

Because of its large size, a tractor-trailer often appears to be traveling slower than it is.

On multi-lane highways tractor-trailers stay in the center lane to help local traffic flow on and off the highway and to keep the driver’s options open.

A truck in the middle can move either way if something goes wrong, which is worth more than being out of the way.

Staying in the middle lane also increases a truck driver’s options if they switch lanes to avoid a dangerous situation or a crash.

No vehicle in Utah may have a total outside width, including its load, of more than 8 1/2 feet, and a farm tractor may not exceed 9 feet.

Eight and a half feet is what a lane will take. Anything wider needs a permit and an escort.

No vehicle shall have a total outside width, including load, of more than 8 1/2 feet. One exception to this rule is farm tractors. Their width may not exceed 9 feet.

No vehicle in Utah may exceed a height of 14 feet including any load carried.

Every bridge and tunnel in the state is built to clear that figure. Exceeding it finds the one that does not.

No vehicle shall exceed a height of 14 feet, including any load that may be carried.

No single Utah vehicle except fire-fighting equipment may exceed an overall length of 45 feet including the bumpers.

Past that length a vehicle cannot make an ordinary turn without using the oncoming lane.

No single vehicle, except for fire-fighting equipment, shall exceed an overall length of 45 feet, including the front and rear bumpers.

A combination of Utah vehicles, such as a motor home pulling a boat, may not exceed a total length of 65 feet.

This is the figure a family towing a trailer is most likely to break without ever thinking about it.

All other combination of vehicles, with or without a load (such as a motor home pulling a boat), may not exceed a total length of 65 feet, 8 feet in width, and 14 feet in height.

No Utah vehicle may carry a load extending more than three feet to the front or more than six feet to the rear of the vehicle body.

A load hanging out the back is invisible from the side and lethal at a corner. Six feet is the limit without a permit.

No train of vehicles or single vehicle shall carry a load extending more than three feet to the front nor more than six feet to the rear of the vehicle’s body.

No Utah vehicle may carry a load extending beyond the line of the fenders on the left side, or more than six inches beyond them on the right.

Nothing may stick out on the traffic side at all, because that is where oncoming vehicles pass closest.

No vehicle, including a passenger vehicle, may carry any load extending beyond the line of the fenders on the left side of the vehicle nor extending more than six inches beyond the line of the fenders on the right side.

Every Utah vehicle registered for 16,001 pounds or more must display its registered weight on both sides in letters not less than two inches high.

The number on the door is what tells an officer, and a bridge inspector, what is going over it.

The Utah State Tax Commission requires that every vehicle registered for 16,001 pounds or more have the weight for which it is registered displayed on both the left and right sides of the vehicle.

A driver of a large vehicle should slow down when clearance is under six inches, because rough roads might bounce the vehicle into a low ceiling.

Six inches sounds like plenty until a pothole uses it. Slowing keeps the bounce smaller than the gap.

When your clearance is under six inches, be safe and slow down.

What share of fatal truck crashes are caused by the other vehicle?

71 percent. Seven in ten of these crashes are the car driver’s doing, which is the opposite of what most drivers assume. Utah Driver Handbook 2026-2027, p.78: “According to the National Highway and Traffic Safety Administration (NHTSA), 71% of fatal crashes involving two or more vehicles, one of which is a truck, are caused by another vehicle, usually a car.”