Forman said three-prong brushes on PRT vehicles can be become misaligned, scraping the ramps that guide the vehicles due to carbon buildup from the machinery.
The scraping brushes, carbon buildup and speed of the vehicle can cause a "fireball effect," he said.
"It would take a substantial fire for the vehicle to be engulfed or for the passengers to be in any danger," Forman said. "The outside (of the vehicle) and the carpet inside are completely fire resistant."
Because the Feb. 25 incident happened in a low-speed area, more passengers were subject to seeing more of the fire than if the PRT was traveling fast along the track, he said. Usually, impending flashes or fireballs happen very quickly, Forman said.
PRT employees, who call the occurrences an "HV1," locate the short circuits on the track to fix areas where the buses could be scraping because of carbon buildup.
Students should insist on an independent investigation to determine whether the "fireball effect" is dangerous.