The change comes as a result of 19 Xfinity teams being penalized at Chicagoland.
During the Chicagoland NASCAR Xfinity race, 19 teams, including the race leaders were penalized when they entered a closed pit road, despite the Tower radioing that pit road was open.
"When you looked at it, the tower did come over the radio and say pit road was open," said Steve O'Donnell, Vice President of Competition for NASCAR. "The person at the opening did not hear the radio communication so the red flag and the light were still on."
With just 49 laps remaining, it was a crucial set of stops that shuffled the front of the field with only a handful of the more observant noticing the red lights and flag before it was too late.
As a result, NASCAR has mandated that the Tower now has the power to control the pit entrance lights, rather than an official stationed on pit road. The change affects all three national series and is effective immediately.