WASHINGTON, D.C. — The National Transportation Safety Board (NTSB) has released its full report on the fatal 2010 Gray Summit, Mo., crash that involved a pickup truck, a truck-tractor and two school buses.

As SBFreported in December, the NTSB called for a nationwide ban on driver use of nonemergency personal electronic devices while operating a motor vehicle after its meeting on the accident.

In the crash, a pickup truck ran into the back of a truck-tractor that had slowed due to an active construction zone. The pickup truck, in turn, was struck from behind by a school bus. That school bus was then hit by a second school bus that had been following. Two people died, and 38 others were injured in the incident.

The NTSB's investigation revealed that the pickup driver sent and received 11 text messages in the 11 minutes preceding the accident.

NTSB determined that the probable cause of the initial collision was distraction, likely due to a text messaging conversation being conducted by the GMC pickup driver. The agency also found that the second collision, between the lead school bus and the pickup, was the result of the bus driver's inattention to the forward roadway, and the final collision was due to the driver of the following school bus not maintaining the recommended minimum distance from the lead school bus.

Moreover, problems were found with each bus’ brakes. In terms of the lead bus, NTSB found that once power was restored to the bus and the engine was started, neither the ABS warning indicator nor the brake system warning indicator illuminated when the bus was running, and during deceleration testing. In the absence of power and with the engine off, the brakes functioned with manual hydraulic force only.

In addition, the brake lines that ran from the master cylinder to the hydraulic ABS unit appeared to be corroded and leaking, while corrosion was present on a few areas of other brake lines. When the brake pedal on the lead bus was depressed, the movement of the pedal was soft and spongy, and a brake fluid leak was observed in the brake lines running from the master cylinder to the ABS unit. Upon further examination, it was found that one of the bus’ brake lines had a 0.06- by 0.03-inch hole.

In regard to the second school bus, NTSB found that the company that owned the bus had fabricated a spring assembly to help return the brake pushrod from a braking actuation to its non-braking position in an attempt to turn off the service brake application indicator light on the dash. Inspection of the brake lines from the master cylinder to the wheels revealed corrosion in some locations.

The bus was equipped with an ABS ECU, which recorded ABS configuration and diagnostic-related data. Upon examining the data, eight inactive diagnostic fault codes and one active fault code were discovered — this resulted in frequent error signals from the left rear wheel speed sensor. Also, the ABS was not functioning at the bus’ right rear tire.

In addition to the buses' brake problems, NTSB found upon touring the bus company’s facilities that there did not appear to be any set maintenance schedule for the buses or any established method of retaining maintenance records. Neither the owner nor the mechanic had any formal training in the service or maintenance of passenger or heavy-duty vehicles.   

NTSB made several recommendations following its investigation of the crash, including that the National Highway Traffic Safety Administration (NHTSA) modify FMVSS 217 to require that all emergency exits on school buses be easily opened and remain open during an emergency evacuation.

The agency also made specific recommendations to the state of Missouri, addressed to the governor. Among them are to revise bus evacuation regulations to require that students traveling to an activity or field trip in a school bus or school-chartered bus be instructed in safe riding practices, and on the location and operation of emergency exits prior to starting the trip.

NTSB also made recommendations to the Missouri Department of Elementary and Secondary Education, CTIA — The Wireless Association and the Consumer Electronics Association, the National Association of State Directors of Pupil Transportation Services, the National Association for Pupil Transportation and the National School Transportation Association, and it reiterated previously issued recommendations.

For example, the agency recommended that NHTSA determine whether equipping commercial vehicles with collision warning systems with active braking and electronic stability control systems will reduce commercial vehicle accidents. If the technology is determined to be effective in this purpose, NTSB would like NHTSA to require its use on commercial vehicles.

The report also includes statements from several NTSB members. Vice Chairman Christopher Hart said that he agrees with most of the findings and the recommendations, as well as the probable cause of the crash, but he has a “concern about how [the NTSB] addressed the issue of driver distraction,” and he added that the recommendation to ban the nonemergency use of portable electronic devices for all drivers “may be scoped too narrowly.”

“Drivers can be distracted just as much by installed electronic devices as by portable electronic devices, so our limitation to portable devices does not fully respond to the problem,” Hart said. “Moreover, portable electronic devices that are designed to support the driving task can be just as distracting as those that are not. Consequently, I believe we should follow up on a suggestion that was mentioned in our Sunshine Meeting for this accident, which is to convene a forum that would look more broadly at the issue of distraction of drivers by electronic devices, both portable and installed.”

Hart suggested that a forum that considers the viewpoints of a variety of experts, as well as the viewpoints of manufacturers, commercial vehicle operators and drivers, could provide a “solid” foundation for the agency to make additional recommendations that more fully and directly focus on the target of driver distraction “without creating unintended consequences, and without resulting in undue or unnecessary burdens.”

To read the report, click here.