And while a more than 3 percent drop in car deaths over the same period was largely accomplished by technological improvements like airbags, electronic stability control and anti-lock brakes, the trucking industry has resisted most of those safety devices. The Centers for Disease Control and Prevention estimates the annual cost to the economy of truck and bus crashes to be $99 billion.

A number of changes that will inevitably make us all less safe are tucked into the pending highway bill, currently stalled because of differences between the House and Senate versions. In fact, Congress has failed to adopt a comprehensive highway funding bill for years, relying instead on dozens of temporary extensions since 2009 to keep any semblance of a federal road construction program moving. In July, the House and Senate passed another temporary patch, good through the end of October.

The crash involving Tracy Morgan shows why Congress needs to toughen its oversight of trucking, not loosen it. The driver who caused the crash was in a modern 18-wheeler that was well maintained and managed, owned and operated by Walmart. As detailed in the causation report on the crash released earlier this month, the National Transportation Safety Board found that the driver had been on duty for about 13 and a half hours; federal rules allow a 14-hour workday. About a mile before the crash, the driver ignored work-zone warning signs on the New Jersey Turnpike of likely delays ahead. About a half-mile later, the posted speed limit dropped to 45 m.p.h. from the usual 65, which the driver also ignored.

Mr. Morgan’s Mercedes van was moving at less than 10 m.p.h. because of the construction. The truck driver, fatigued and slow to react, according to the N.T.S.B., was unable to stop in time, and slammed into the van, turning it on its side and jamming the passenger door closed. According to the board, if the driver had slowed to 45 when warned to do so, he should have been able to stop before crashing. But before his official work day began, the driver, the board found, had spent 12 hours driving his own vehicle from his home in Georgia to pick up his truck at a Walmart facility in Delaware, and had been awake for 28 consecutive hours at the time of the crash.

Large trucks are disproportionately involved in fatal accidents. While heavy trucks accounted for less than 10 percent of total miles traveled in the United States during 2013, according to federal data, the N.T.S.B. recently reported that they were involved in one in eight of all fatal accidents and about one-quarter of all fatal accidents in work zones, like the crash that injured Mr. Morgan.