WASHINGTON The National Transportation Safety Board thinks operator members of the American Bus and United Motorcoach associations should be encouraged to install onboard brake stroke monitoring systems on their vehicles.

Heres the story behind the safety board recommendation:

On June 24, 2011, a small Nevada trucking company that specializes in hauling ore and gravel had one of its Peterbilts on the road, pulling two empty trailers, with 9 of the 16 brakes out of adjustment or not working, driven by a driver who had an "erratic employment history" with as many as 30 jobs during the previous 10 years.

The 105-foot-long rig was traveling northbound on U.S. 95, also known as the Lovelock Highway, about three miles south of Interstate 80, when it crashed into the side of an Amtrak train that was passing through a grade crossing. The truck was going at least 58 miles per hour as it approached the crossing.

The collision, which destroyed the truck, tore gapping holes in the sides of two railcars and ignited a fire that engulfed both damaged railcars and part of a third. The crash killed the truck driver, the train conductor, and four train passengers; 15 passengers and one crewmember were injured.

According to the NTSB, when the grade crossing signals activated, the truck was more than 2,300 feet from the tracks. However, investigators found no evidence the truck driver began braking until the front of the truck was less than 300 feet from the crossing.

"Although well never know the exact cause of the truck drivers inattention, we do know that if John Davis Trucking had provided its driver with a safe and properly maintained vehicle, this accident could have been avoided," said NTSB Chairman Deborah A.P. Hersman.

Through accident reconstruction and physical evidence, the NTSB determined the truck was traveling at 26-30 mph when it struck the train.

In addition to the trucks marginal brakes, the anti-lock braking systems on both trailers were not functional; wires to missing sensors were cut and zip-tied, and wires to malfunction indicator lights had been disconnected.

This raised "serious questions about the maintenance practices" of John Davis Trucking of Battle Mountain, Nev., said the NTSB.

Several months after the collision, NTSB investigators went back to the crash site and conducted a series of tests using a truck with good brakes.

The test showed that if the accident truck been able to decelerate as well as the test vehicle, the accident would have been completely avoided; the accident truck would have stopped 15-67 feet short of the rail tracks, the NTSB said.

As a result of its investigation, the NTSB made 20 safety recommendations to John Davis Trucking, the Federal Motor Carrier Safety Administration, the National Highway Traffic Safety Administration, the Federal Highway Administration, the Federal Railroad Administration, the Nevada Highway Patrol, the Commercial Vehicle Safety Alliance, the American Trucking Associations, the Owner-Operator Independent Drivers Association, the Towing and Recovery Association of America, the American Bus Association, and the United Motorcoach Association.

John Davis Trucking is strongly disputing several of the NTSB conclusions and findings. It has posted a statement on its website, http://www.jdt3d.net/.

The NTSB recommendation to UMA and ABA asked the associations to inform their members of the circumstances of the crash "and encourage them to install onboard brake stroke monitoring systems on their commercial motor vehicles."

Onboard brake stroke monitoring systems automatically relay information about air brake adjustment and operational status to drivers, inspectors and maintenance personnel. The systems can detect major brake problems in real time.

Typically, brake stroke monitoring systems are designed for vehicles with air-activated drum brakes. Most systems are not designed for disk brakes, which have been standard on motorcoaches for the better part of a decade, and they cannot be used with hydraulic brake systems, which are generally found on many cutaway bus chassis.

The installed cost of an on-board brake adjustment monitoring system depends on the type of system purchased and how its purchased. Costs range from roughly $1,200 to $2,500; $2,000 is fairly typical.

Costs may also vary depending upon the type of vehicle and the number of axles. In addition, some systems might require the replacement of the existing spring brake chambers with sensor-equipped chambers, which could increase the cost.

Aftermarket kits are available.