Until now, cars could race back to the start-finish line when the yellow flag came out. But that created the potential for a major accident and one was almost caused last week in Richmond.
Bill Elliott, who was leading the race, slowed down to avoid a wreck that had brought out the yellow flag. Behind Elliott, however, cars were racing hard to get past him and regain a lost lap.
The change of rules also affects the NASCAR Busch and truck series.
"We have monitored and continually discussed, internally, the situation regarding racing back to the yellow and have reached the conclusion that it is time for us to take this step," NASCAR President Mike Helton said.
"We will eliminate the practice completely."