With the traditional pair of mega-scissors, officials opened the largest segment of the controversial Intercounty Connector highway on Monday by slicing through a ribbon. It was green.

With just one spur between Interstate 95 and Route 1 still to be built, the 50-year-0ld war over whether to build an east-west highway that sliced across Maryland north of the Capital Beltway was a major step closer to victory for those who believe that it will ease traffic congestion and revitalize the economy of Prince George’s County, always a stepchild in the region’s economic expansion.

Choosing a green ribbon might have symbolized the belief of the highway’s proponents that in building the most expensive transportation project in the state’s history they have painstakingly addressed the concerns of environmentalists who fought the road at thousands of meetings, hearings and in court over five decades.

“A trip from Laurel to Gaithersburg today takes 47 minutes,” said Lt. Gov. Anthony G. Brown (D). “Tomorrow, it will take 17 minutes. Building the ICC has been a resounding success.”

The roadway, a smaller portion of which opened in February, is scheduled to open for traffic at 6 a.m. Tuesday. Though it is a toll road, tolls for the full 17.9-mile length of the ICC will be suspended until Dec. 4. Contracts that will extend the highway almost a mile to Route 1 are expected to be awarded this year or early in 2012, with a 2014 completion date.

The ribbon-cutting drew scores of current and past appointed and elected officials to a stretch of the new highway just west of I-95.

“Few projects in this state have been discussed and debated as long as this one,” said Maryland Transportation Secretary Beverley K. Swaim-Staley.

Prince George’s County Executive Rushern L. Baker (D) said the road would create job opportunities in his county, and Montgomery County Executive Isiah Leggett (D) warned that without a state gas tax increase, other highway and transit projects would be jeopardized.

Greg Smith, one of three ICC opponents cordoned off to one side of the event, said the billions invested in ICC construction threatened funding for other transportation projects.

“They’re already raising tolls across the state to pay for this project,” Smith said.

Smith also said that the tolls, which vary depending on the time of the day, will deter many drivers from using the road, reducing the anticipated income from tolls.