Commuter trains will pass over and under roads and arroyos as they travel to Santa Fe later this year.

Work is ongoing to make the crossings safe and effective, according to those planning the state's Rail Runner Express train and overseeing construction of new tracks on the approach to Santa Fe from Albuquerque.

Motorists on Interstate 25 have recently driven by large steel beams and pre-cast concrete forms that are making up four rail bridges between the freeway's north and southbound lanes.

"For the most part they are traditional railroad stuctures. They are pretty cookie-cutter," said Paul Lindberg, project engineer with the state Department of Transportation.

Designs call for "simple span" bridges, which means the steel beams that carrry weight are sitting on pads. Each independent beam attaches to a pier. One end is fixed and the other has about an inch of room for stress-reducing expansion caused by temperature shifts, he said.

Next is the deck, made of reinforced concrete, that crosses each bridge. Railroad ballast, piles of black basalt, will then separate the deck from the train track.

The bridges under construction to take the train over N.M. 599, Richards Avenue and Cerrillos Road are not likely to be pink and blue like "The Big I" interchange in Albuquerque, Lindberg said. Instead, they will be painted to blend in with the landscape.

"They will probably be kind of a dirt color," he said.

Meanwhile, the train is slated to pass under roads at four points. Rail Runner Express trains will travel on exisiting freight track from Albuquerque to a point near Waldo Canyon, where the state is building new track to avoid the steep grade.

Twice on private property, the trains will dive under a road, then perform the same feat for several hundred yards to get into and out of the Interstate 25 median.

Construction on the box culverts pulled several hundred thousand cubic feet of earth from the areas near the rest stop at the top of La Bajada and at the end of Galisteo Road near St. Francis Drive.

Inside the city limits, all 11 train/road crossings are at grade, which means they are separated from traffic only by signals and gates.

Three wooden, rustic railroad bridges will mostly stay in place, but they won't carry the tracks anymore, said Chris Blewett, project manger with the Mid-Region Council of Governements, on contract with the state.

The wooden bridges along Galisteo Road will remain in use for bicyclists and pedestrians on the Rail Trail, while new concrete bridges or culvert pipe will be in place for the train crossing, he said.

Contact Julie Ann Grimm at 986-3017.