How can OTR truck drivers know every bridge/ overpass clearance?
No, OTR truck drivers DO NOT know every bridge and overpass along their route because their route can change from day to day. BUT… The driver MUST know the height of their own trailer or loaded combination, and should watch for warnings or placards indicating low bridges. In the USA, the minimum height for Interstate overpasses is 15 feet.
There are several ways to know the clearance. #1 it's usually posted on the overpass #2 map books sometimes have a section that you can look up the overpass for clearance height #3 some states have maps that show overpasses and the stated clearance #4 some truck GPS's have overpass clearance #5 if all else fails, GOAL. (G = get. O = out. A = and. L = look.)
Well, if a bridge is usually low, they have advance warning... And they should know how tall their HGW is... If they think they can slip under it", they are kind of idiots...
You MUST know your truck, tractor and trailer height, and pay attention to the clearance signs on bridges. After a while, you will get a feel for what is happening. It helps to be driving in familiar territory. If you are in unfamiliar territory, you need to be extra vigilant.
most are marked .........................
They know their truck height. Many times when overpasses are destroyed it is because of a dump truck that still has the box in the Dump position that takes out the overpass. In some towns there are TRUCK ROUTES that TRUCKERS know and use because they will not fit under all the underpasses and low power lines. They have no need to go through the middle of town, so the route goes around the town. Much less traffic and there is no overpasses...or sharp corners or narrow roads(which take care of the extra wide and long loads)
They don't, but they know where to find that information.
Most bridges on main roads are of a minimum clearance that all trucks can pass under. All bridges below that clearance have their height clearly marked on the centre of the arch. Truck drivers should know the height of their vehicle. Good truck drivers can judge to an inch whether they can get under a bridge. Sometimes they get it wrong.
It's marked on the bridges and maps, oversize loads by law must have a set of radio chase cars to warn oversize loads to exit and reenter the road if the overpasses are not high enough. Then the front chase car will block the bridge ahead with cones and or flairs so the oversized load can pass back onto the highway as the rear clearance chase car will assume the front position ahead down the road. You will notice these yellow strobe lit chase cars as they usually have a cargo tall fiberglass rod affixed on the bumper to judge the adequate height of the under pass bridges and radio back the info to the over size load truck driver.
Yes they really do. In most places the clearance is required by law to be a certain minimum height.