Plans to build a bicycle and pedestrian bridge spanning Highway 101 are moving forward two years after the issue threatened construction of a new Santa Rosa Junior College parking garage.

On Tuesday, the Santa Rosa City Council is expected to award a $117,598 contract to Steven Grover Associates of Berkeley to determine the cost and timing of the bridge project, and most importantly where it will land on each side of the freeway.

"It's going to be huge," Mayor Bob Blanchard said, citing preliminary estimates that the bridge, including ramps to accommodate the disabled, will be more than 1,500 feet long.

The span, estimated to cost $5.5 million two years ago, is now pegged at $9 million, a figure that could increase before it's actually built.

Supervising Engineer Steve Dittmer said it will be at least three years before the project moves forward and then, Blanchard added, only if enough outside funding can be secured.

"It will be built sooner or later," Blanchard said, explaining that the feasibility study will be the basis for seeking state and federal grants for construction.

So far, the only money raised for the project is what the city plans to spend on the feasibility study and $1 million set aside by the junior college as part of a legal settlement.

That settlement was the result of a lawsuit filed in October 2004 by the Sonoma County Bicycle Coalition, which challenged an environmental study for the five-story, 1,100-space junior college parking garage.

The coalition contended the study didn't adequately address parking alternatives to the garage, which opened this year.

The group agreed to drop the lawsuit in March 2005 when college officials agreed to pay $1 million toward construction of the proposed bicycle and pedestrian overcrossing.

Blanchard said the decision to move ahead, despite the lack of funding, is largely fueled by that settlement because the $1 million offer expires in 2012.

"We have our eye on that $1 million," he said.

The overcrossing has been part of the city bicycle and pedestrian master plan since 2001.

Christine Culver, executive director for the bicycle coalition, welcomed news the project is moving forward.

Culver said it will provide bicyclists a much safer route to travel between the junior college area on the east side of Highway 101 and Coddingtown and a proposed commuter rail station on the west side.

She said making a cross-town trip today requires bicyclists to use either Steele Lane or College Avenue, which are among Santa Rosa's more dangerous streets because of their high volume of motorists.

How heavily the overcrossing would be used by cyclists and pedestrians isn't known, although Culver said a survey of junior college students and employees indicated many would ride their bikes to school if it were built.

Culver said even at $9 million, the overcrossing is a bargain to move people across town compared to the $111.5 million currently being spent to widen to six lanes a two-mile stretch of Highway 101 through the heart of Santa Rosa.

Blanchard thinks an overcrossing would receive heavy use, both because of the "thousands of kids who go to that college on a daily basis" and plans to build high-density housing along the west side of the freeway, partly to fuel greater ridership on the proposed commuter rail system.

Dittmer said one of the bigger issues the study will help decide is where the ramps should be built.

Each ramp will be 400 to 500 feet in length, equal to the span crossing the six-lane freeway, to meet federal Americans with Disability Act standards.

While the east-side ramp will land somewhere on the junior college campus, several sites on the west side, including property on Foley Avenue near a proposed train station or further north nearer Coddingtown, are potential sites.

Dittmer said whatever sites are selected, they probably will need to be perpendicular to the freeway to keep costs within reach.

You can reach Staff Writer Mike McCoy at 521-5276 or mike.mccoy@pressdemocrat.com.