Is a recent driver death an isolated incident, or a part of a pattern of inadequate federal oversight?

The commercial vehicle unit of the California Highway Patrol is investigating a November 22 accident that may have been caused by mechanical problems. Witnesses say the brakes on a 1989 International semi were smoking just before it dove off the 150-foot Clavey River Bridge outside of Sonora, killing the 26-year-old driver.

Other factors may come to light as the investigation proceeds. The crash was only the first of two accidents in four days, involving the same contractor carrying rice straw mulch to the Stanislaus National Forest. No one was injured when a 2005 Freightliner tipped over November 25th. (The U.S. Forest Service uses the mulch to cover areas denuded by fire.)

However, the Clavey River Bridge crash is not the first time this year that the CHP has investigated a commercial vehicle fatality, in which the brakes were suspect.

On February 3, a tour bus went out of control and hit a pickup truck before overturning in the mountains near San Bernardino, killing seven passengers, as well as the driver of the pickup. CHP crash investigators confirmed the bus driver’s report of a catastrophic failure of the brakes.

Two weeks before the Clavey River Bridge accident, the National Transportation Safety Board called for a probe of the Federal Motor Carrier Safety Administration, citing the California tour bus crash and three other incidents nationwide. The NTSB questions whether the FMCSA is doing its job effectively.

On November 7 the NTSB argued that if the FMCSA had properly inspected the tour bus, it might not have been on the road at all. A lengthy NTSA inspection revealed that all six brakes on the bus had defects, including worn-down linings, as well as drums that were either worn or cracked. Yet a month prior to the California crash, the FMCSA had apparently inspected the bus and cleared it for service.

The other three crashes cited by the NTSB involved another tour bus near Pendleton, Oregon, in December of 2012, a truck-tractor semitrailer near Elizabethtown, Kentucky in March, and a tractor-trailer outside of Murfreesboro, Tennessee in June.

The driver in the Oregon crash lost control on a slippery highway, sending his bus through a barrier and down a steep slope, causing nine deaths. The driver had been on duty for 92 hours during the eight days preceding the crash, exceeding the federal limit of seventy hours. The bus was going too fast for poor weather, and its transmission retarder was engaged. A transmission retarder limits speed, but should not be used when roads are slick, as it can cause the wheels to skid.

The Canadian company operating the tour bus in Oregon had received a satisfactory safety rating from American inspectors in 2011. In March of 2012, it has resumed U.S. operations after paying a late fine for not testing its U.S. route drivers for drug and alcohol abuse.

An NTSB review afterward of the 2011 inspections revealed “longstanding and systemic” problems dating to the bus company’s first American operations in 2007. The NTSB stated that the 2012 tragedy “might have been prevented if the (FMSCA) had exercised more effective federal oversight” during inspection.

The truck involved in the Kentucky crash in March rear-ended an SUV, pushing it into a third vehicle. The SUV burst into flames, killing six of its eight occupants and injuring the two others.

Kentucky State Police and the NTSB investigated the crash, and found the driver had been keeping double records of his driving hours. The first set, which he gave the police, matched his employer’s records and showed compliance with federal hours-of-service regulations. A search revealed the second set, which showed that on the day of the crash he was behind the wheel for the tenth day in a row, in violation of HOS rules.

The trucking company was inspected by the FMCSA five days before the Kentucky crash, but the focus of the inspection was too narrow to include scrutiny of drivers’ compliance with HOS regulations.

The driver in the Tennessee crash was also violating HOS rules when his truck collided with eight other vehicles, killing two and injuring six. A review of his employer’s records found four more drivers with similar violations.

Aware of repeated HOS violations by the company’s drivers, the FMSCA had conducted only a narrowly focused safety inspection in 2011, and had allowed the company to continue operating.

Jacqueline Gillan, president of Advocates for Highway and Auto Safety, called the NTSB’s findings “very disturbing and, frankly, deadly for the public.”

The FMSCA pointed out investigators did end up shutting down the company that owned the tour bus involved in the California crash. But the NTSB wants the Motor Carrier Safety Administration to be proactive, rather than responding to high-profile accidents.

The FMCSA claims it has more than tripled the number of unsafe companies and drivers it has taken off the road over the past three years, by conducting more comprehensive investigations. The agency released a statement saying “we have also brought together key safety, industry and enforcement organizations to ask for their help and support our efforts…. We are continuously looking for new ways to make our investigation methods even more effective so we can shut down unsafe companies before a crash occurs, and will thoroughly review the NTSB’s findings.”