The push-to-pass system has been utilized at Toronto and Edmonton with an activation delay of 5 seconds introduced at Mid-Ohio on Aug. 5. The delay was reduced to 3.5 seconds for the GoPro Indy Grand Prix of Sonoma on Aug. 26. The system will have no delay for the final road/street race of the 2012 season at Baltimore.

"We've had two races without the activation delay and two races with it," INDYCAR Director of Engine Development Trevor Knowles said. "Based on driver feedback, we're adjusting the parameters of push to pass to fit this particular circuit."

A total of 90 seconds will be afforded drivers, with a maximum of 20 seconds per activation on the 2-mile temporary street circuit. There's no recharge time between activations.

The overtake assist feature, introduced to the series in 2009, allows a driver to add turbocharger boost and additional RPMs with the press of a button on the steering wheel. When the system is engaged, the turbocharger boost increases to 160 kPa with an additional 200 RPMs on the 2.2-liter V6 engines supplied by Chevrolet, Honda and Lotus.