Transit planners say that Wake County's first light-rail trains will hop out of the crowded railroad corridor as they approach downtown Raleigh, and they'll roll through city streets alongside cars and trucks.

But which city streets?

That's one of the tough transit questions posed in a series of free public workshops across the region, which started last week and will conclude Thursday.

Some Triangle residents have anguished for the past 20 years over how - and whether - to build a regional transit network with trains and better bus schedules.

The last regional plan crashed in 2006 because it was weak on local political and fiscal support, and federal transit officials concluded that it would not serve enough riders to justify the expense. Local political leaders have been more closely involved this time in developing detailed transit plans for Wake, Durham and Orange counties.

Even after they find consensus on the technical issues, they'll face a tougher political test on the question of whether better transit is worth higher taxes. Planning boards and county commissioners will consider whether to adopt the plans and whether to schedule a referendum on a half-cent sales tax to help pay for trains and buses.

This week's workshops will give Wake, Durham and Orange residents a chance to catch up with evolving plans for:

Commuter trains between Garner and West Durham.

A light rail line between northwest Cary and northeast Raleigh.

A route involving either light rail or bus rapid transit between downtown Durham and UNC Hospitals in Chapel Hill.

Beefed up buses and downtown circulators or trolleys to augment current routes and serve future rail stops.

Commuter trains, using existing Amtrak-freight tracks, could be up and running in as little as six years, say officials with Triangle Transit, the three-county bus agency that is overseeing the effort to develop a new bus-and-train plan.

Durham and Orange

On workday mornings, these rush-hour trains would take workers and students from west Durham to Research Triangle Park and downtown Raleigh, and from the east side of Garner through RTP to west Durham and Duke University.

Several alternate routes are under review for a transit route between UNC-Chapel Hill and Durham. The Meadowmont community in east Chapel Hill was designed for transit lines, but some residents there don't like the idea, so an alternate route is on the table. There are questions about where to put the terminal station at UNC-CH.

And the biggest question for the Durham-Chapel Hill line is whether to use light rail trains or the fancy kind of rubber-tire vehicle called bus rapid transit. This involves special buses running at least part of the way in their own special roadways or in reserved street lanes where cars are not allowed to get in the way.

Options in Raleigh

In Raleigh, four options are being weighed for light-rail trains that would run alongside freight tracks as they approach downtown from the west.

From there, the trains could possibly:

Leave the rail corridor between Central Prison and Goodnight's Comedy Club, roll down West Morgan Street, turn left onto Harrington Street and rejoin the corridor on the north side of downtown;

Climb high above the tracks on a viaduct that would pass over the Boylan Avenue bridge, arc across the busy intersection of three railroad tracks called the Raleigh Wye, stop to let off passengers at the planned rail-transit Union Station, and come back down to earth - to travel alongside cars on either West Street or Harrington Street;

Head southeast from Boylan on a mile-long viaduct that would end at South Street. Then the trains would run northbound on Wilmington Street and southbound on Salisbury Street.

Each choice carries its own problems and advantages.

The Salisbury-Wilmington layout would run closer to the big downtown job centers, serving more daytime riders. But it would be a mile longer, with higher costs and longer trip times than the other routes through downtown.

For the shoppers

One last question lingers at the end of the line, in northeast Raleigh just inside the 540 Outer Loop. Early plans called for a light-rail station at an inaccessible site on the west side of Capital Boulevard.

A promising new alternative would carry the trains east of Capital Boulevard for two stops at Triangle Town Center and a big park-and-ride lot.

bruce.siceloff@newsobserver.com or 919-829-4527