WASHINGTON, D.C. — School buses and other heavy vehicles should be equipped with technology to prevent unintended acceleration, the National Transportation Safety Board (NTSB) concluded in a report adopted Tuesday.

The agency said that a brake transmission shift interlock device, which requires the driver to apply the brakes to shift out of park, would have prevented a 2007 school bus loading zone crash in Falls Township, Pa., that injured 20 students. The bus suddenly accelerated at a high school, struck several students and then crashed into a retaining wall.

In its investigation of that accident, the NTSB determined that the probable cause was a pedal misapplication by the driver. Pedal misapplication occurs when a driver depresses the accelerator instead of, or in addition to, the brake pedal.

Contributing to the occurrence of pedal misapplication in the Falls Township accident was the driver’s unfamiliarity with the school bus, the NTSB said. It was a substitute bus, and the pedals were different from what the veteran driver was used to.

Now the NTSB has called on the National Highway Traffic Safety Administration (NHTSA) to require brake transmission shift interlock devices in heavy vehicles susceptible to pedal misapplication. The board also recommended that NHTSA conduct an analysis of pedal configurations in heavy vehicles and study the effect of pedal design on the driving task.

Additionally, NTSB recommended that the National Association of State Directors of Pupil Transportation Services and the National Association for Pupil Transportation advise their members of the dangers of pedal misapplication and to consider driver refresher training and suggested mitigation strategies.

The NTSB held a public meeting Tuesday on its special investigative report on pedal misapplication, which also covers the 2005 school bus crash in Liberty, Mo., in which two people were killed.

A synopsis of the report is available online now. The full report will be available within several weeks, the NTSB said.