After years of planning and political maneuvering and with a successful tax election behind it, now comes the fun part of building a commute railroad that will traverse Sonoma and Marin counties.

The first work has already begun, a $25 million project to reopen the Northwestern Pacific Railroad's tunnel near San Rafael for tracks and a bike-pedestrian pathway.

The 1,100-foot tunnel collapsed in the 1990s and was badly damaged by fire, about a decade after the railroad discontinued using the line.

The historic tunnel, first constructed in 1884, is just south of San Rafael and is the portal to Larkspur, the commute line's southern terminus.

Next comes the design of the rail cars that will include the floor height, how much room is allocated for bicycles, bathroom configuration and whether there will be food and beverage kiosks, along with tolerances for vibration and ride quality.

The fleet is expected to cost $89 million and will be the most visible part of the 70-mile, Cloverdale-Larkspur line.

"This will be the most physical part of it, it will be our brand, what the cars look like," said SMART spokesman Chris Coursey.

Consultants will design the rail cars, stations and a maintenance facility, aid in the purchase of real estate for the maintenance facility and two stations and engineer repairs and replacing track and three bridges.

"This all of a sudden becomes exciting," said Jake Mackenzie, a Rohnert Park councilman and member of the Sonoma Marin Area Rail Transit board of directors. "It was nervous time up to last November's election, up to the sales tax measure we were not able to start the process of getting trains on tracks."

The consulting contracts will extend to 2014, when trains are scheduled to begin running, and cost an estimated $25 million.

"This is all work that is critical to the project to move forward," Coursey said. "We need to award these contracts and get the design done, and we can begin building."

The maintenance facility is expected to cost $22 million and will be where the fleet is stored and serviced and also house the operations and dispatch center.

SMART is looking at property near Shiloh Road in Windsor and near the train station in Cloverdale.

SMART also is looking at property near Frances Avenue in Santa Rosa and near Corona Road in Petaluma for station sites.

The 14 railroad stations, expected to cost $31 million, will be covered platforms that will have ticket machines and seating, but not be enclosed buildings, and parking.

Track will replaced and upgraded to a standard that will allow trains to run at 70 mph, along with upgrades of bridges in Healdsburg, Petaluma and San Rafael, at a cost of $102 million.

You can reach Staff Writer Bob Norberg at 521-5206 or bob.norberg@pressdemocrat