To weigh in to make sure that they are not overloaded (because they causes more stress on the roads sometimes in towns at stop lights and stuff you can see the grooves in the tarmack were the trucks come through alot)
Some states may require it. Ports of Entry in New Mexico require rental vehicles to stop.
Interstate weigh stations require any large truck to stop at the stations when they are open and active. A dump truck qualifies as a large truck that would need to stop.
Some states do require it. Some states require all rental vehicles to stop at ports of entry (New Mexico is one).
No, weigh stations are for commercial cargo vehicles.
If they would be considered a CMV without the farm plates, yes.
If requested to do so
Commercial fright haulers have to be weighed at a weigh station to enforce weight restrictions. Since the federal restriction is 80,000 pounds trucks weighing more than that need a special permit.
Yes, all commercial trucks must enter all weigh stations. Execpt most newer scale houses are all electronic, so if your weight is ok you might get the by pass light and just keep going. If your weight is close to the limit, they will have you pull on the scale to check your weight. Being overweight can be very expencive.
In most states, no. However, some states may require commercial vehicles with a GVWR of as little as 8000 lbs. to stop at weigh stations.
Official weigh stations are operated by the highway department for the enforcement of laws relating to maximum load limits and have no services available to the general public. (It's a bit like asking if you can buy donuts at a police station.) However, it's not uncommon for "truck stop" type service stations to have unofficial scales for drivers to check their load to make sure they're within the legal load limit.
Longer stopping distances. A passenger car may weigh 3,000 pounds. A large truck may weigh 90,000 pounds. It is much harder to stop.
Trucks weigh many times more than fifty kilograms, which is less than the average adult person weighs.