Truck brake check areas are a safety measure that allows truckers to pull safely off the road to check the operation of their air brake systems. Some brake check areas are mandatory; failure to stop in the designated area, and to check the brakes, is a violation of the law. Others are voluntary, and stopping to perform a brake check is left to the discretion of the driver.
Typically, places to perform a brake inspection are located just before a long, steep downgrade (or hill) in an attempt to prevent the loss of a truck's braking power during descent. The air brakes on a heavily-laden tractor trailer are subject to considerable overheating if improperly used in even normal driving. Descending a downhill grade significantly increases brake use because of the design and weight characteristics of these vehicles.
Over-use of air brakes while traveling on a long downgrade will heat the brake drums and shoes to the point where the brakes are of little or no use. This braking condition is known as brake fade, and is a major contributor to accidents involving tractor trailers. For this reason, truckers are encouraged to inspect their brakes at a brake check area before they begin driving down. Brake fade on a loaded rig usually results in the driver either using a truck runoff area, if possible, or a crash.
At the brake check area, drivers physically check each of the various components of the air brake system for wear, leaks, or damage. This check includes the air compressor, air drier, brake lines, trailer supply and emergency air hoses, and especially the brake drums and shoes. Once the check is complete, drivers must record the results of the inspection in their driver's vehicle inspection report (DVIR), as well as in the driver's log book.
Recording the stops and the results of the brake checks are federally mandated requirements for truck drivers in the U.S. Failure to comply can result in fines and imprisonment for both the driver and his employer. At the very least, a driver risks permanent loss of his commercial driver's license (CDL) for either failing to stop at a mandatory brake check area or neglecting to properly record the stop.
Some of the larger brake check areas provide parking space for trucks. If a trucker is close to the maximum allowed driving limit, 11 hours straight in many places, the trucker can pull into a space for the mandated ten hours of rest between driving stints. Such rest stops also must be recorded in the driver's log.