NASCAR banned drivers from racing back to the yellow flag under caution, changing a rule strongly criticized by drivers and team owners.

The new rule, which takes effect for this weekend’s races, forbids passing once the caution flag is displayed. NASCAR president Mike Helton said Thursday the change was needed “to further ensure the safety of the competitors.”

Drivers had been allowed to continue racing at full speed under caution until they got back to the flagstand at the finish line. At that point, they had to slow and line up behind the pace car.

Despite the old rule, drivers had been expected to follow a Gentleman’s agreement and hold their positions when the caution flag came out. That agreement was often ignored.

Last Sunday at New Hampshire International Speedway, Dale Jarrett crashed and found himself sitting in his battered car in the middle of the track on the main straightaway. The rest of the field came out of the fourth turn at full speed, in some cases three-wide, racing to the yellow flag.

Somehow, nobody hit Jarrett’s car, but it was just the latest example in a long series of dangerous situations in recent years.

The biggest flap this season came in June in Sonoma, Calif., when Robby Gordon passed Richard Childress Racing teammate Kevin Harvick under caution and went on to win.

Harvick and four-time series champion Jeff Gordon criticized Robby Gordon (no relation) for the move. The winner insisted he did nothing wrong.

“I didn’t break any rule,” he said. “I was trying to win a race. That’s my job.”

After last Sunday’s near-miss, there was a loud outcry from the drivers.

“We’ve been very lucky over the years that we haven’t had a serious problem,” two-time series champion Terry Labonte said.

Helton said other aspects of the change would be outlined to Winston Cup and Busch Series competitors at a meeting scheduled Saturday morning in the garage area at Dover International Speedway.

The NASCAR Craftsman Truck Series drivers and crew chiefs will hear the same message later Saturday.

“We needed to find a better way to do it rather than racing back to the yellow, and the new procedures we are putting in place are the first step in the process,” Helton said.

He said new procedures for pit road entry will also be discussed at the meetings, but gave no indication what that would entail.

Busch driver Hmiel suspended

Daytona Beach, Fla. — Busch Series driver Shane Hmiel was suspended indefinitely by NASCAR Thursday for violating the sanctioning organization’s substance abuse policy.

“NASCAR has a zero tolerance for any type of behavior in violation of our substance abuse policy,” NASCAR president Mike Helton said.

Helton did not specify the substance involved, but said Hmiel could seek reinstatement after agreeing to attend counseling and undergo periodic random testing.

NASCAR’s substance abuse policy was created in 1988 and provides for testing under “reasonable suspicion.”

Hmiel, son of Steve Hmiel, the director of motorsports and technical operations for Dale Earnhardt Inc., is eighth in the Busch Series standings, with four top-five finishes in 26 starts this season.