Raleigh, N.C. — A half-cent sales tax could ease traffic congestion across the Triangle in the future, a transportation group said Friday.

The Special Transit Advisory Commission has been hammering out plans for a regional transit system for almost a year, and its members are close to selecting three or four areas across Wake, Durham and Orange counties for the first phase of the project.

"You have the Capital Boulevard/U.S. (Highway) 1 corridor, perhaps out to (Interstate) 540 and then to downtown Raleigh, and downtown Raleigh to Cary, and those follow existing rail corridors. Then, in the Durham-Chapel Hill area is the (U.S. Highway) 15/501 corridor," STAC member Smedes York said.

The commission is looking at linking Research Triangle Park and Raleigh-Durham International Airport to any regional system, which they hope to launch by 2020 and complete by 2035.

"In 12 years, 13 years, we can put it on the ground," STAC Vice Chairman Bo Glenn said.

A half-cent sales tax could generate $90 million a year to fund the system, which would include a mix of street cars, express buses, light rail and commuter rail lines, officials said.

"Different parts will look different. Certainly, I think there will be very high ridership, and we want to start with corridors that will be successful and then build momentum to build the rest of the system," York said.

The effort is being patterned after a transit approach Charlotte has been working on for the past decade. Officials said a similar sales tax in Mecklenburg County has generated about $70 million a year.

A regional transit system is the best way to move people across the Triangle without adding cars and more congestion to area highways, which already experience bumper-to-bumper traffic most days.

"The projections are almost doubling the population in the next 30 years," Glenn said.