Single-car qualifying for Denver and Miami

The rule change, which will only be in effect for the two races, will see both Friday and Saturday sessions run in the format, which has been adopted by Formula 1 for this season. CART also ran single-car qualifying at Brands Hatch this year, because of the tight nature of the circuit.

"These changes will not only provide a better and safer racing environment for our teams," said Lee Dykstra, CART's director of technology. "It will also give our fans a truer look at the performance of our teams and drivers during qualifying sessions."

The Friday qualifying session will run in reverse order of Friday morning practice times, with final qualifying on Saturday running in reverse order of the first session results. Any driver that returns to the pits before taking the green flag will get another chance to run once all other drivers have qualified, but any driver that runs at least one green flag lap will not be allowed to do so.

The current qualifying format, where each driver is free to complete 15 laps in a 40-minute session, has caused controversy at times this season, with numerous accusations about blocking during the sessions. In the recent race at Vancouver, Paul Tracy was stripped of his fastest time during Friday qualifying after he was deemed to have blocked opponents.