Santa Rosa today will consider spending up to $200,000 to study whether it makes sense to build a tunnel under the SMART rail line to help pedestrians and bicyclists go under the tracks at Jennings Avenue.

The location has been used for years by pedestrians and bicyclists to get across the tracks, which bisect Jennings Avenue.

With the anticipated arrival of commuter rail service on the line in 2015, the crossing will have to be either fenced off to prevent unauthorized use or upgraded with a safe crossing approved by the state Public Utilities Commission.

Work on the track in the area is expected to move forward in October, and if a tunnel is going to be needed, the contractor needs to know soon, explained SMART Chief Engineer Bill Gamlen.

If the measure is approved, the city would agree to pay Sonoma Marin Area Rail Transit up to $200,000 to conduct the environmental review and design. If the study shows a tunnel is feasible, the city likely would shoulder most of the $1.8 million cost of the project, according to a city staff report.

The city's Bicycle and Pedestrian Master Plan envisions some kind of a crossing at the location, about three blocks south of the future rail station at Guerneville Road near Coddingtown mall.

People cross there now in part because residential neighborhood is located on the east and there is an employment center on North Dutton Avenue to the west.

"It's amazing how many people use that crossing," said Colleen Ferguson, deputy director of public works.

The approach under consideration would involve gradually raising the rail bed to a height that would allow walkers and bikers to pass underneath, Ferguson explained

She noted that without the crossing there will be nowhere for pedestrians and bikers to cross the tracks between Guerneville Road and College Avenue, a distance of nearly a mile.

A less expensive ground level crossing faces its own obstacles. The PUC already has said another at-grade crossing will not be allowed at this location, and SMART doesn't want one, either, Gamlen said.

"We already have a lot of crossings on this railroad; we don't want to have anymore," Gamlen said.

You can reach Staff Writer Kevin McCallum at 521-5207 or