NEW BRUNSWICK — Kevin Roper had not slept for more than 24 hours when the rig he was driving on the New Jersey Turnpike hit a limousine van early Saturday morning, killing one passenger and injuring four others — including the actor and comedian Tracy Morgan — authorities said today.

Roper, 35, of Jonesboro, Ga., who is charged with vehicular homicide and four counts of assault by auto, is free on $50,000 bail and faces his first court appearance in New Brunswick on Wednesday.

State Police would not release Roper’s driving record, but disclosed in court documents that he had gone a full day without sleep before the accident.

However, a spokeswoman for Wal-Mart said Roper, who has been placed on administrative leave, "was operating within the federal hours of service regulations."

"The details are the subject of the ongoing investigation and we are cooperating fully with the appropriate law enforcement agencies," the spokeswoman, Brooke Buchanan, said. "The investigation is ongoing, and unfortunately, we can’t comment further on the specifics."

According to the Federal Motor Carrier Safety Administration, Wal-Mart drivers have been involved in nine fatal accidents in the past two years, but the company — which reported 667 million vehicle-miles traveled last year — has a "satisfactory" safety rating.

The issue of driver fatigue comes as the U.S. Senate considers rolling back a 70-hour cap on a trucker’s work week that went into effect last July, limiting driving to 11 hours a day.

Last week, Sen. Susan Collins (R-Maine), a member of the Appropriations Committee, proposed a change that would suspend the rules reinstating an 82-hour workweek the industry is pressing to restore. A spokesman for Collins said the amendment, adopted on a 21-9 vote, "would not change the mandatory 30-minute rest break during a shift, nor would it change the total number of hours a driver can legally work during the day."

In 2003, New Jersey became the first state to make it a crime of vehicular homicide for causing a fatal accident while driving drowsy.

Kevin Roper, a Wal-Mart truck driver from Georgia, was charged with death by auto and four counts of assault by auto in connection with a deadly crash on the New Jersey Turnpike early Saturday morning.

The statute, known as Maggie’s Law, made it illegal for a driver who had been awake longer than 24 hours to operate a vehicle.

The law was named for 20-year-old Maggie McDonnell, who was killed in 1997 when a driver awake longer than 24 hours crossed three lanes of traffic and hit her car head-on.

A spokesman for Morgan said today that the comedian remained in critical but stable condition at Robert Wood Johnson University Hospital in New Brunswick, where he had surgery on his leg.

Morgan, 45, suffered a broken leg, broken nose, and several broken ribs in the crash that killed James McNair, 62, a comedian known as Jimmy Mack. McNair, of Peekskill, N.Y., wrote for Morgan and was a close friend.

Morgan, best known for his work on the NBC television programs "30 Rock" and "Saturday Night Live," was returning from a performance at Dover Downs Casino in Delaware when the crash occurred about 1 a.m. Saturday.

Ardie Fuqua, 43, a comic from Jersey City, and Morgan’s assistant, Jeffrey Millea, 26, of Shelton, Conn., were also listed in critical condition, according to a hospital spokeswoman.

Harris Stanton, 37, of Brooklyn, another passenger in the van, was treated at the hospital and released.

Morgan’s spokesman, Lewis Kay, said his recovery will be arduous.

"His fiancée Megan is by his side," Kay said in a news release. "The concern for his well-being has been overwhelming, but Megan is respectfully asking that the media await official word through these channels before speculating (mostly inaccurately) on his condition."

Authorities said Roper failed to see slow-moving traffic ahead of his tractor-trailer as he passed through Cranbury, slamming into the rear of Morgan’s van and causing a chain reaction that involved four more vehicles, including another rig.

Bill Simon, the chief executive of Wal-Mart, released a statement over the weekend, saying that "if it’s determined that our truck caused the accident, Wal-Mart will take full responsibility."

The investigation into the crash is being led by the New Jersey State Police and the National Transportation Safety Board. The U.S. Department of Transportation yesterday said its investigators also were involved.

State Senate President Stephen Sweeney (D-Gloucester), who sponsored Maggie’s Law, said he hoped the accident would lead to further examination of how to prevent people in need of sleep from operating a vehicle.

"The effects of sleep deprivation can be just as hazardous as those of drugs and alcohol," Sweeney said.

Star-Ledger staff writer Ted Sherman contributed to this report.

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