Being in a loaded truck on a steep down grade, what happens when the brakes fail is the stuff of truckies’ nightmares. The realisation of the power of the mass onboard the truck, combined with the knowledge you are not in control and simply a passenger is hard to take. However, it does happen, and with surprising regularity. Many drivers have gone through the sphincter tightening experience this truck driver from the US goes through, as the truck hits the arrester bed and then comes close to rolling over.
No-one wants to come close to this experience, but we must all mentally prepare for it, if we are going to drive trucks at high masses on a down grade.
These road engineers from Arizona explain the basic layout of the emergency lane and how it works:
In Wyoming the authorities use this unusual net system, when there is not the room for a traditional arrester bed. I have seen a different solution in Europe, a lane filled with 200 litre plastic drums, filled with liquid:
If it all goes wrong, this is what can happen: