Truck escape ramps stop out of control big wheeler's by use of arrested beds that are large areas of gravel or sand.
When the big wheeler or semis wheels or wheel hits the gravel or sand the material in the area then moves away from each other which allows the truck or big wheeler to sink into the gaps that helps stop the vehicle.
The big wheeler or semi truck loses traction on the sand and gravel and also the incline helps bring the truck to a stop.
A truck escape ramp is an emergency area located adjacent to a downgrade roadway to provide a location for out-of-control vehicles to slow and stop away from other vehicles on the road.
They are generally located near the middle or the end of long, steep downgrades.
Truck drivers don't reverse down the hill once they're there.
They need a tow, and while the state doesn't fine drivers for using runaway truck ramps, towing companies charge trucking companies to remove the vehicles from the runaway ramps.
By definition, runaway truck escape ramps are designed to be emergency locations that use sand, gravel, or wire nets to slow down a large vehicle quickly in the event of a brake failure.
Most of these ramps make use of arrester beds, which are large areas of sand, or gravel.
There are two types of runaway truck ramps: Gravity ramps: A truck takes the ramp and experiences an uphill grade that naturally will stop it.
Gravel arrester beds: These are on a flat-level grade.
Trucks taking the ramp will run into a bed full of small, round gravel.