LEMONT, Ill. (STNG) - Today marks the opening of the new 12 1/2-mile extension of I-355, offering potential relief to motorists who’ve endured some teeth-grinding delays in the corridor that runs roughly from Bolingbrook on the north to New Lenox on the south.

On Sunday, just in time for Veterans Day, officials dedicated the south extension and the rest of I-355 as Veterans Memorial Tollway. It’s a “daily salute” to our military, said Illinois Tollway Board Chairman John Mitola.

He spoke Sunday at the dedication in southwest suburban Lemont that gave humans, not vehicles, the run of the new road. Pedestrians meandered across lanes to check out road equipment and listen to speeches by Gov. Blagojevich and Tammy Duckworth, head of the state Department of Veterans Affairs.

“It means a lot to me, that this is named for the ordinary GI,’’ said Duckworth, a pilot who lost her legs serving in the Iraq war.

Today, “50,000 commuters’ll be able to drive on I-355, and they’ll be able to take 20 percent off of their travel time,’’ Blagojevich said.

The I-355 south extension is Illinois’ biggest tollway opening in 40 years, Mitola said.

The $730 million project through Will, DuPage and Cook counties began in 2005 and came in six weeks ahead of schedule, said Tollway Board Executive Director Brian McPartlin.

Bridgette Mlady, whose grandfather, Andrew Frain, founded Chicago’s Andy Frain security firm, said the extension will shorten her commute from Lemont to Oak Brook, where she helps run AF Services.

“It’s going to cut off 15 minutes,” she said, as her children Kassandra, 8, and Michael, 11, climbed on road equipment on display.