PORTLAND, Ore. — The bicycling commuter in pipestem jeans is not just a caricature of nerdy Pacific Northwest cool. Miles driven per year in old-fashioned automobiles — partly through dint of pedal power and pedestrians — are lower now than in 1995 here on Multnomah County’s major thoroughfares, according to state figures, even as the population has grown by more than 21 percent.

But follow the bike lanes and greenways north to the Columbia River, where the spidery steel trusses of the Interstate 5 bridge clutch the banks, and Portland looks like any typical American city, choked by traffic. The oldest elements of the bridge date from 1917.

These intertwined, competing identities are central to what comes next for the Columbia River Crossing, a $3.4 billion bridge-replacement project of new highway ramps, traffic lanes and light rail linking Portland to Vancouver, Wash., that was supposed to resolve a traffic choke point. The old plan, after more than 20 years and tens of millions of dollars’ worth of studies, was killed last month by the Washington State Senate after the Republican-dominated majority coalition declined to vote on financing it.

The governors of Oregon and Washington, both Democrats, immediately ordered further planning work halted.