Which stops shorter, a semi-truck or a car?

Question

My friends and I were having a discussion about this and we couldn't come to an agreement: which will generally stop shorter from a given speed in average weather conditions - a semi or a car?

Obviously, the tractor-trailer weighs much more, meaning more force would be required to stop it... but also meaning the frictional force exerted on the road would be higher.

I know the answer depends largely on how the semi is loaded and such, but just assume everything to be average.

If possible, citing sources would be great. Thanks!

Answer 1

Historically, generally, the car stops in a shorter distance. ABS (antilock braking systems) shortens the stopping distance in some conditions, but not in the standard dry-pavement conditions. But truck brakes are seeing much more dramatic improvements. Modern air brakes, properly adjusted, allow an arbitrary amount of force to be applied. New disc and drum designs are improving efficiency, fade resistance, and so on. Yes, you still see runaway truck lanes, but nowadays they are seldom used. I lost points on my driving test because I braked too hard, and that was even an older vehicle. The National Highway Traffic Safety Administration (NHTSA) in the US is rewriting its rules, acknowledging that semi stopping distances are considerably shorter than they once were.

The car is no longer the clear winner, and might no longer be the winner at all.

Answer 2

all i know is trying to stop a semi with a full load behind it on an icy road and then tell me who has the advantage. this is why drivers of cars should never just cut into the path of the semi without signaling (not at the last min) or cutting the semi off. i have drivin a semi a few times in the military. plus on the current job i have i have driven tugs with 3 or 4 containers behind them fully loaded (about 1000 to 1800 pounds each) and it has pushed my tug alot further then i would have ever thought. also have driven forklifts too. i think the car will always have the stopping advantage no matter what brakes are on the semi becouse the semi driver normally tows a pretty big load behind him. the semi drivers that carry steel beams know that if they get in a wreak the steel could shift the load and go threw the cab. so think before you cut someone off on the highway.

Answer 3

If the brakes and tires are in proper working order, and the truck driver is able to keep the trailer straight behind him, he should have the same stopping distance as the car. If the truck jack-knifes, the driver may have to reduce braking power in order to straighten the trailer. If the truck rolls over, the metal rubbing against the pavement will probably have a lower coefficient of friction than the tires. Either way the trucks stopping distance will be longer.

Answer 4

depends on the velocity and mass, if the car was loaded with tons of stuff and at a speed at 100 mile/h, and the truck is only at 10 miles/h, then the car will take longer time to stop

Answer 5

gas expenses protection themes Emissions Noise pollutants those are only some dumb motives human beings could protest 18 wheelers. None of those are valid motives. gas expenses will impression the tip client, by fact drivers will only could develop their quotes. occupation drivers are meant to do a protection examine of their vans and trailers earlier and after each shift, and that they are on the line as much as 11 hours an afternoon as expert drivers. New vans are burning air purifier than ever with extra valuable gas injection structures and emissions contraptions. New vans are additionally quieter, in spite of the Jake Brake on than the older vans ever could desire to be

Answer 6

The semi takes farther, the car takes shorter. I don't know the scientific explanation but it is in my state's driver manual. I just took the driver's license test and that question was on there.

Answer 7

it depends on the mass of the objects!