Local politicians and planners in Portland want commuters to keep their cars at the curb, and they’re calling on “Godzilla” for help.

Next spring, Portland will begin building its first bridge over the Willamette River in 37 years. The Willamette River Transit Bridge — which will link a future Oregon Health & Science University campus on the west side of the river with a museum and opera house on the east — will be 71 feet wide and feature 14-foot-wide paths on both sides for bicycles and pedestrians. The bridge’s middle will provide space for public-transit vehicles but no private cars. The active-transit structure, a critical piece of a 7.3-mile light-rail line that will link downtown Portland with the south suburb of Milwaukie, will be the first of its kind in the United States.

“We’re thrilled to have the first bridge of this kind right here in Portland,” said Gerik Kransky, advocacy director with the Bicycle Transportation Alliance, a Portland-based advocacy group.

Kransky said the Willamette Transit Bridge’s bike-ped lanes will be four feet wider than those on the busy Hawthorne Bridge, which also connects downtown Portland with the Central Eastside Neighborhood. The residential-industrial enclave links up with the Springwater Corridor, a popular route for commuter cyclists.

Metropolitan government officials explored adding automobiles to the $135 million bridge but balked at a bigger price tag, noted Mary Fetsch, a spokeswoman for TriMet, the region’s public transit operator. Officials also found that bridge connections to the interstate system would not meet federal standards, and local road connections would be inadequate to handle more car traffic.

Even in bike-friendly Portland, not everyone is rosy about a bridge closed to cars, however. And some folks find the bridge’s design downright scary.

San Francisco-based architect Donald McDonald’s bridge, more than 1,700 feet long, will feature two 181-foot-tall towers that anchor cables that rise from the river like a sea monster’s fins. The massive structure will sit between the Ross Island and Marquam bridges, which are less than a half-mile apart. A 2009 editorial in The Oregonian newspaper dubbed the bridge “Godzilla on the Willamette” and charged it would “severely limit” limit residential development on both sides of the river.

“Who will want to live near it,” the columnist asked rhetorically. “I have my doubts that anyone will.”

The Bicycle Transportation Alliance, which consulted transit engineers and planners on the bridge design, doesn’t have an official opinion on the bridge’s aesthetics, Kransky said. “Personally, I think it’s beautiful,” he added.

If construction goes as planned, the bridge will open in the fall of 2015, when Portland and surrounding Multnomah County’s population is projected to be more than 30 percent greater than it was in 1980.