A three-county citizen advisory group agreed today to push for an ambitious transit expansion program including increased bus service across the Triangle and $2 billion in rail projects that would link Chapel Hill to North Raleigh by 2020.

Those rail projects would include 56 miles of tracks through Durham, RTP, Cary and downtown Raleigh.

Triangle voters could cover about half the cost if they agreed to two new local levies — a sales tax increase of half a penny per dollar, and an added $10 per car annual registration fee — or their equivalent, leaders of the Special Transit Advisory Commission said.

The group agreed to push for 25 percent funding from the state and 25 percent funding from Washington.

The 29-member advisory group was charged last spring with rethinking the region’s transit priorities after the Triangle Transit Authority’s 28-mile rail project was derailed in 2006. That $810 million plan lacked local political and fiscal support, and federal regulators said it would not serve enough riders to warrant the heavy taxpayer investment.

The transit group draws optimism from recent transit success in Charlotte — where riders, voters and developers are on board with the city’s expanded bus and rail service.

Its leaders say they hope to succeed where TTA failed in 2006 by aiming higher, not lower, to build local support that TTA lacked; by improving bus service quickly to help the region and to complement train schedules; and by attracting dense mixed development to focus Triangle growth along the rail lines.

The proposal calls for money to:

• add new bus lines and improve existing bus networks with at least 120 new buses in a region that now has about 240 public transit buses;
• build an electric-powered light rail line from UNC Hospitals in Chapel Hill to downtown Durham, 16 miles at an estimated capital cost of $739 million in 2007 dollars;
• extend tracks for TTA’s self-propelled diesel rail cars from Duke Medical Center through Durham and Research Triangle Park to northwest Cary, 19.7 miles at an estimated cost of $580 million;
• run the same diesel rail cars from northwest Cary to downtown Raleigh and then north to Durant Road in North Raleigh, 20.6 miles for an estimated $734 million.

Many details must be worked out in a final report to be circulated by Feb. 22 and voted upon at the group’s next meeting Feb. 29. Then it will be in the hands of Wake, Durham and Orange county elected officials.