NEW YORK —
"We have also brought together key safety, industry and enforcement organizations to ask for their help and support our efforts," the statement said. "We are continuously looking for new ways to make our investigation methods even more effective so we shut down unsafe companies before a crash occurs and will thoroughly review the NTSB's findings."
Tour and intercity buses carry about 700 million passengers a year, second only to domestic airlines, which move around 785 passengers annually.
The NTSB also posted online evidence gathered in two commercial truck crashes. In one crash near Elizabethtown, Ky., last March, a truck-tractor semitrailer rear-ended an SUV carrying eight people, pushing it into another car. The SUV exploded in flames. Six of the vehicle's occupants were killed and the other two were injured.
An investigation by Kentucky State Police and NTSB revealed the truck driver had been keeping two sets of records on his hours behind the wheel, the board said. The records he gave police, which matched the truck company's records, indicated he was following federal regulations. The second set, found during a search, indicated he was driving for the 10th consecutive day on the day of the crash in violation federal regulations, the board said.
The trucking company was inspected by the motor carrier administration five days before the crash, but the inspection was narrowly focused and didn't include examining driver compliance with hours-of-service regulations.
The second truck crash occurred in June near Murfreesboro, Tenn. A tractor-trailer collided with eight other vehicles just past midnight. Two people in a 2003 Honda that overturned were killed. Six of the 13 people in the other vehicles were injured.
The truck driver had violated federal rules limiting the hours drivers can spend behind the wheel, and a review of the company's records found four more drivers with similar violations.
The motor carrier administration knew of repeated hours-of-service violations by the company's drivers but conducted only a narrowly focused safety inspection in 2011 that allowed the company to continue operating.
The motor carrier administration oversees more than 525,000 truck and tour and intercity bus companies and has about 350 safety inspectors. Overall, state and federal motor vehicle safety inspectors conduct more than 3.5 million truck and bus inspections across the U.S. each year.