Sharing with large trucks — Missouri Permit Test

A typical tractor-trailer may weigh up to 80,000 pounds, and depending on the trailer the combination may exceed 90 feet in length.

Eighty thousand pounds does not stop or turn like your car. Every other truck rule follows from that number.

A typical tractor-trailer combination, a power unit pulling a loaded semitrailer hinged to its rear end, may weigh up to 80,000 pounds.

On busy intercity routes a motorist may meet double or even triple-trailer combinations sometimes exceeding 100 feet in length.

A hundred feet takes a long time to pass and a long time to clear. Starting the pass without knowing that is how it goes wrong.

a motorist may encounter double or even triple-trailer combinations sometimes exceeding 100 feet in length

Tractor-trailers take longer to stop than cars traveling at the same speed.

Same road, same speed, far more distance. Cutting in front of one takes away the room it needs.

Tractor-trailers take longer to stop than cars traveling at the same speed.

A truck may have two or three times more power than a car, but with up to 70,000 pounds of trailer and cargo behind it the engine must move 30 or 40 times more weight.

The power is there and it is not enough. That is why the truck at the light is still crawling when you are up to speed.

a truck engine must move 30 or 40 times more weight than a car engine

A semi-trailer combination accelerates slowly, and the truck may have to go through ten gears to reach the speed limit.

Ten gears is a long climb. Pulling out in front of one and then slowing is the version of this that ends badly.

The truck may have to go through ten gears to reach the speed limit.

Do not enter a roadway in front of a large vehicle, and avoid changing lanes in front of one if you are turning off the roadway.

The truck cannot brake out of the trouble you create. Pulling in and then slowing to turn is the specific mistake.

Do not enter a roadway in front of a large vehicle.

Never underestimate the size and speed of an approaching tractor-trailer, because its size often makes it appear to be traveling more slowly than it is.

Large things look slow. Pulling out on that impression is how car-truck collisions happen at intersections.

Because of its large size, a tractor-trailer often appears to be traveling more slowly than its actual speed.

Vehicles carrying hazardous materials must stop at all railroad crossings, so be prepared.

A tanker stopping at a crossing is obeying the law, not breaking down. Expecting it keeps you off its bumper.

Vehicles carrying hazardous materials must stop at all railroad crossings.

Because of their size, large trucks may swing out to the left as the first step in making a right turn, so watch their turn signals before trying to pass.

A truck moving left is often about to go right. Reading that as a lane change puts you exactly where the trailer will sweep.

large trucks may swing out to the left as the first step in making a right turn

When traveling up or down steep grades, large vehicles must drive slowly in the right lane, so avoid driving in the right lane on those hills.

The right lane on a grade belongs to whatever is struggling. Being in it puts you between a truck and its only option.

When traveling up or down steep grades, large vehicles must drive slowly in the right lane.

Near truck weigh stations, avoid driving in the right lane so slow-moving trucks can merge back onto the roadway.

Trucks rejoin the road there at walking pace. Leaving the lane clear is what lets them do it without a standing start into traffic.

When you are near truck weigh stations, avoid driving in the right lane so slow-moving trucks can easily merge back onto the roadway.

What may a typical tractor-trailer combination weigh?

Up to 80,000 pounds. Eighty thousand pounds does not stop or turn like your car. Every other truck rule follows from that number. Missouri Driver Guide, p.29: “A typical tractor-trailer combination, a power unit pulling a loaded semitrailer hinged to its rear end, may weigh up to 80,000 pounds.”