NASCAR placed drivers Kurt Busch and Tony Stewart on probation for six races Tuesday, beginning with the Daytona 500.
The punishment stems from a confrontation between the two former series champions, who wrecked in practice last week and carried it into the NASCAR officials' trailer.
While nobody involved in the incident would confirm that Stewart punched Busch during a meeting with officials, as is widely believed, NASCAR vice president of competition Robin Pemberton inferred that Busch's penalty was for what happened on the track and Stewart's was for what happened afterward.
"The accident was a racing incident," Pemberton said. "How they conducted themselves after that, after the accident and coming onto pit road and from there through the rest of the evening is why the penalties were equal."
Stewart said Saturday that he and Busch had agreed to put the incident behind them.
NASCAR officials have said drivers would get more latitude to show emotion, and the relatively light nature of Tuesday's punishments seem to support that.
NASCAR spokesman Ramsey Poston said the measures would have been more severe if Stewart and Busch had rubbed fenders while pit crew members were working on pit road, endangering their safety.
Probation has been a murky issue for NASCAR, as officials haven't necessarily punished a driver more harshly if he misbehaves while on probation. Spokesman Jim Hunter said that's going to change.
"We're starting the season by putting them on probation and we're also going to redefine what probation means," Hunter said. "And they clearly understand it."
HAMILTON FASTEST:Lewis Hamilton, the first black driver in Formula One who was racially taunted by fans almost two weeks ago in Barcelona, returned to Spain and was the fastest in opening a three-day test session in Jerez De La Frontera.
The McLaren driver completed 89 laps and had a best time of 1 minute, 19.102 seconds. Teammate Pedro de la Rosa was second, less than 0.2 seconds behind. BMW Sauber's Robert Kubica, Williams' Kazuki Nakajima, BMW's Nick Heidfeld and Renault's Nelson Piquet Jr. all finished under 1:20.
CHAMP CAR: Team owner Derrick Walker says the Champ Car series has run its final race and is making preparations to compete in the rival Indy Racing League this season. Champ Car executive vice president David Higdon reiterated the league's position that the series still plans to run its regular schedule in 2008.