NASCAR has banned car-to-car radio communications in its latest bid to prevent tandem drafting at Daytona and Talladega.
Several changes have been made to the cars and engines ahead of this year's Daytona 500 to make it more difficult for drivers to draft in pairs.
Until now, drivers were able to tune in to each other's radio frequencies to arrange drafting partners, but this has been outlawed by the governing body.
Sprint Cup director John Darby said: "It's not like we're taking away a tool that was commonly in use. Last year there were four races where we saw driver-to-driver communications [two at Daytona and two at Talladega].
"The teams will still have the ability to talk amongst themselves. The only thing the new rule controls is the actual car-to-car communication."
Darby added that he understood drivers were working with as many as 30 different channels on their radios, which some were finding confusing and distracting during a race.
"[The drivers] felt it would be better if we could back that off somewhat and get it to a standard or more common communication between driver and spotter and driver and pit crew as we've known it before," he added.
"Matt Kenseth said the best. He said anything that NASCAR can do to help us get back to one against 42 others, he supports, and I think that's part of it.
"The teams will still work inside the rule, whether it's spotters on the roof, swapping notes back and forth. But it just seemed like that would be helpful to unclutter the airwaves a little bit."