RALEIGH - The Triangle can afford to expand bus service and build new rail projects if local leaders make a "Charlotte level of effort," the head of a regional transit agency said Friday.

A new half-cent local sales tax could augment local and state transit funds to pay for 150 new buses in the next few years and launch more than $1 billion worth of capital projects by 2020, said David King, general manager of the Triangle Transit Authority.

King spoke to members of a three-county citizens panel that began rethinking the region's public transportation plans after the Federal Transit Administration pulled the plug on the TTA's 28-mile, $810 million regional rail project in 2006.

"We assume no federal help now," King said. "But even a 10 percent federal share of major new transit investment would change this dramatically and put us in position to be able to afford more."

Charlotte and Mecklenburg County have used a half-penny sales tax to enlarge their bus fleet and launch a 10-mile light-rail line that has served 12,000 riders a day since it opened in November.

King said a similar tax or its equivalent would produce about $82 million a year now in Wake, Durham and Orange counties, with revenues expected to grow about 5 percent per year.

Combined with the region's car rental tax and expected funding from the state, that money could give the Triangle about $2 billion by 2020 -- enough to buy 150 new buses, build $1.05 billion in new rail or other capital projects, and operate the expanded service, he said.

The Special Transit Advisory Commission will issue recommendations next month on where to provide new bus, train and streetcar service and how to pay for it. The three-county group met for seven hours Friday to begin narrowing choices. It plans two more meetings in the next seven weeks.

TTA's plan for a Raleigh-to-Durham rail link was low on the list of favorites at Friday's meeting.

Most members of the group favored a big expansion of regional bus service, unspecified "circulator" service for Research Triangle Park and Raleigh-Durham International Airport, and bigger investments at either end of the region:

* UNC-CHAPEL HILL TO DOWNTOWN DURHAM. Capital costs for electric-powered light-rail trains are estimated at $670 million to $810 million for the 16-mile route. The price tag would be lower -- $490 million to $600 million -- for curb-guided buses, which ride concrete tracks like trains and operate on city streets like other buses.

* DOWNTOWN RALEIGH TO DURANT ROAD IN NORTH RALEIGH. Self-propelled diesel rail cars would travel 10 miles north along former CSX tracks. Some members of the group would extend rail service all the way north to Wake Forest.

Included are few stops along the badly congested U.S. 1 and a big park-and-ride lot near Durant Road north of the I-540 Outer Loop. By 2035, planners say, 380,000 trips will begin and end in this corridor each day.

"That area needs immediate relief from congestion," said Durham lawyer Bo Glenn, one of the panel's vice chairmen. "And a majority of Triangle residents would see this as a positive first step."

Some members favored trains from downtown Raleigh to Cary. Capital costs for a 19-mile line from Cary to Durant Road are estimated at $620 million to $750 million.

Bill Cavanaugh of Raleigh, co-chairman of the 29-member transit committee, said a key part of the plan will be streetcars or other circulators for RTP and downtown work centers.

"You need them to move people around in small parts of the region and allow them to connect onto a major corridor that would take them all the way across the region," Cavanaugh said.