Workmen check on last-minute details for Tuesday’s opening of the Intercounty Connector near Georgia Avenue and Norbeck Road. (Linda Davidson/THE WASHINGTON POST)

All interchanges were open by 12:45 a.m., officials said.

“Everything has been going very smoothly,” said Cheryl Sparks, spokeswoman for the Maryland Transportation Authority.

Drivers have been able to use six miles of the ICC between Interstate 370 in Shady Grove and Georgia Avenue, just south of Olney, since late February.

Motorists can travel the toll road, which provides a new east-west link in the suburbs from I-370 to I-95, for free through Dec. 4. The road’s official designation is MD 200.

Once tolling returns, the pricing will be based on the time of day, with drivers paying the most during peak rush hours. Tolls will be assessed via gantries that will deduct money from an E-ZPass. Drivers without the transponders will receive a toll notice in the mail, which will include a “video tolling fee.” Starting Dec. 5, tolls for passenger cars traveling the entire highway during peak hours will be $4 each way with an E-ZPass transponder or $6 without one.

State officials said the ICC, which was debated for more than 50 years because of its environmental impact, will provide a key east-west link in Maryland’s road network beyond connecting Montgomery and Prince George’s counties. It also will better link Montgomery’s I-270 job corridor with Howard and Baltimore counties and connect Montgomery companies with Baltimore-Washington International Marshall Airport and the Port of Baltimore. The full ICC will cut the drive between Gaithersburg and BWI airport from 71 minutes to 37 minutes, officials said.

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