Every major city has a street that is absolutely hellish, and in San Francisco it's Market Street. It bisects downtown, and with all the buses and taxis and Ubers and automobiles, it's a chaotic and occasionally horrifying three-mile stretch that is best, and worst, traveled by bicycle.

Hundreds of cyclists ride down Market each day, mixing with all manner of motorized mayhem. Designated bike lanes—painted bright green so those in cars and buses know to keep the hell out—help, but it's still pretty damn scary. The occasional plastic bollard is your only protection from the hulking steel coffins speeding past you just a few feet away.

Riding in just about any city is dangerous, and 141 cyclists died in collisions with cars statewide in 2013, according to the California Office of Traffic Safety. That's nearly 20 percent of the 743 cyclists killed nationwide. San Francisco, which has an active and vocal cycling community, saw three cyclists killed last year (out of 29 people killed in traffic accidents), and is rolling out an aggressive plan to eliminate traffic deaths in the city by 2024.

"We've seen that when you build safer streets for people biking, it helps the environment and congestion by encouraging more people to get out of their cars and hop on a bike," says Chris Cassidy, communications director for the San Francisco Bicycle Coalition. "We are pushing for a cross-city network of protected bike lanes because physical separation is key to inviting more people to ride bikes, and to do so safely."

Vision Zero SF includes 24 "priority safety projects" that the city vows to complete by February. The latest of them, "The Raised Bikeway Demonstration Project," is exactly what it sounds like: elevated bike lanes along a two-block stretch of east-bound Market Street designed to prevent encroachment by vehicles. “Cycling on our city streets should not require bravery," says Mike Sallaberry, a senior engineer and 16-year veteran of the San Francisco Municipal Transportation Agency. "Separation has obvious benefits for people on bikes, but people in cars can also predict more easily where a bike is going to be."

Other cities have seen some success with the idea which, like all the best bike-friendly ideas, is put to best use in Europe. The Hovenring in the Dutch city of Eindhoven is a beautiful suspended steel halo that carries cyclists up, over, and around a busy highway. Copenhagen's Cykelslangen lets cyclists cruise over a waterfront district on a bridge as tall as the Chicago L. San Sebastian, Spain, converted an abandoned railway tunnel into a half-mile bike commuter path, and London will spend more than $1 billion on the 18-mile East-West Cycle Superhighway traversing the city. The city has an even more ambitious plan, the SkyCycle pathway, to install more than 130 miles of bike paths above rail lines.

All of which makes the elevated bike lanes in cities like Portland, Oregon, and New York, look a bit underwhelming. Still, it's a start, and San Francisco is using the pilot project to solicit feedback from riders before expanding the project. Despite the monster hills, about 4.41 percent of San Franciscans bike to work, compared to the national average of 0.6 percent. The key to increasing those figures is making cycling safer for all—the keystone of the so-called "complete streets" movement in urban planning that places the needs of pedestrians and cyclists alongside those of motorists.

“It’s a huge challenge to effectively accommodate everyone’s mode of choice, and so we have to make our decisions on how to allocate space," says Sallaberry. "But giving more space to people who walk, bike or take transit is going to be the only way to move people around the city as it keeps growing.”

But it's the bolder infrastructure projects, like the Cykelslangen, that truly encourage people to ditch their cars and make cycling more attractive. Copenhagen has 240 miles of bike paths and a bike commuter rate of 45 percent. As more and more people get packed into every square mile of an urban area, the solutions for mitigating tension between cars and bikes needs to get a lot more creative—like, SkyCycle creative. Part of what makes those Euro cycling utopias thrive is their willingness to be bold.

Similar measures are needed in the US. Our urban centers were not designed with cyclists in mind; we're a car-centric society. American cities can try piecemeal approaches, but the reality is that sharing the road is only a small part of the solution. Bikes and cars need their own dedicated thoroughfares to keep everyone as safe as possible, and to encourage people to choose clip-in pedals over gas ones. Berkeley, California, has done this to some degree with a network of "bicycle boulevards" designed for neighborhood traffic and bicycles. Until San Francisco, or any rapidly growing American city, is willing to make that commitment, every slightly raised bike path will just amount to a series of ad hoc fixes.

1UPDATE 1:35 pm PST 11/25/15: This story was updated to correct the percentage of people who commute by bicycle in San Francisco.