The National Transportation Safety Board (NTSB) is investigating what happened last week when a Greyhound bus headed to St. Louis from Indianapolis struck three tractor-trailers parked along an exit ramp leading to a rest stop area near Highland, Ill.

The accident caused three casualties, with others sustaining serious injuries. During a press conference, NTSB Board Member Tom Chapman said the investigation will center around human performance, survival factors, motor carrier factors, highway factors, vehicle factors, and technical reconstruction, as well as rest area safety, bus occupant protection, potential driver fatigue, and medical fitness.

Chapman added that since 2009, Greyhound has voluntarily added seat belts on their coaches and that the model involved in the crash was a 2014, however, it is not clear how many passengers were wearing their seat belts at the time of the accident.

The Investigation

Chapman explained the NTSB is running a safety investigation in parallel with the law enforcement investigation by the Indianola State Police. The Federal Motor Carrier Safety Administration also dispatched investigators to the crash site. He added the final report from the board will be made available within 12 to 24 months and that the board would not speculate on any of the factors of the crash until it’s report is finalized.

The Greyhound bus was traveling Interstate 70 from Indianapolis to St. Louis with 22 passengers aboard. At about 2 a.m. on July 12, the bus struck the trucks parked along the off-ramp leading to the rest area.

The bus contained both forward-facing and inward-facing cameras, with Chapman saying the data will also be downloaded and examined.

“Assuming it can be recovered and will be shared with us, we have a team of experts who specialize in analyzing and collecting that sort of data,” he said.

Chapman added that although the full investigation could take 12 to 24 months, it’s possible the NTSB would hand out safety recommendations sooner, if necessary.

“If we find in the course of our investigation in the early stages, for example, that it's appropriate to make recommendations before the investigation is completed, we have that ability, that authority, and we do that," Chapman said. "We will make emergency recommendations when it's appropriate to do so when during the fact-finding effort that some condition occurred that needs to be addressed more quickly than it would be if the final results of our investigation held it up."