In its first century as a company, BMW has made industrial engines, motorcycles, Steve Urkel’s Isetta, and a whole lot of cars. Now, it wants to build something altogether new: an elevated bike path.

This week, the automaker’s somewhat redundantly named Research, New Technologies, Innovations division, based in Mountain View, Tokyo, and Seoul, revealed its idea of building a network of bike lanes above street level. It’s called the E3 Way—that's for elevated, electric, and efficient—and BMW says it could help growing cities everywhere fight congestion and ease emissions by making cycling a safer, more convenient, and thus more popular way to get around.

Conceived with help from the School of Automotive Studies and College of Design and Innovation at Tongji University in Shanghai, this network would be reserved for electric bikes and two-wheelers (like the BMW Motorrad X2 City, a battery-powered scooter), and it would have a speed limit of 15.5 mph. If you’re wondering why regular, human-powered bikes don’t seem welcome—well, BMW doesn’t make those.

Like a well-designed highway, the E3 Way would feature ramps and sluice systems to handle merging. Video surveillance and artificial intelligence would monitor the flow of traffic, because what kind of future would it be without constant surveillance and AI? Most of the network will have a roof (no worries about rainy days), and a “cooling system with purified rainwater [that] creates pleasant temperatures,” whatever that means. It’s a lovely vision: Instead of doing battle with cars and pedestrians and whatever else on the street, cyclists get their own safe haven, where they can zoom along, stopping only to pity the poor folks below.

That’s all well and good, but even for a concept, BMW is surprisingly cavalier about what it takes to build infrastructure on this scale. “The best thing is that its modular design and free scalability make the concept essentially suitable for use in any megacity,” the company declares in a press release. “The elevated road is simple and modular in design, [and] economical to build as a result.”

Real world attempts to elevate bike lanes suggest otherwise. In January 2014, to much fanfare, celebrated architect Norman Foster unveiled a plan for a network of aerial cycleways in London, called SkyCycle. Nearly 140 miles of raised, car-free, 50-foot-wide bike paths would connect six million people, accommodating 12,000 riders an hour. In 2016, one of the project’s leaders told cycling website BikeRadar that the $10.7 billion iinfrastructure project was still in the works, but there are no visible signs of progress.

The places that have made elevated bike paths work are those that have reined in their ambitions. In January, Xiamen, in southeast China, opened the world’s longest example, which stretches just under 5 miles. In the Netherlands, Eindhoven’s “Hovenring” has lifted cyclists above a busy intersection since 2012. Copenhagen’s “Cykelsangen” (that’s Danish for “cycle snake”) is just 721 feet long, but lets the city’s many bikers pedal over a waterfront shopping area, instead of pushing through its throngs of pedestrians. Which is to say, the idea seems to work best when applied as a solution to a very localized problem. Lofting a path over an intersection is pretty easy. Moving the entire network of bike paths into the sky demands a gargantuan amount of planning, political will, and cash.

This idea actually dates to the 19th century, when Horace Dobbins of Pasadena, California, wanted to build an elevated path (made of pine and painted green) between his city and Los Angeles, charging 10 cents to ride. He built the first mile of what he hoped would be a nine-mile road, but, as Carlton Reid recounts in his book Roads Were Not Built for Cars, he faced competition from streetcars and railroads, and never got the rest built. “I have concluded that we are a little ahead of time on this cycleway,” Hobbins told The Los Angeles Times in 1900.

Try a century ahead of time, and then some. Well into the new millennium, intolerable congestion, planet-killing emissions, and an increasingly urban world are increasing demand for a new way of moving around. Demand so strong, even automakers like the one building the ultimate driving machine are looking to get into “mobility,” not just cars. BMW, of course, isn’t diving into the infrastructure business. This is a concept, a way of saying Ve are hip, ya! But clearly, the forces now rebuilding the auto industry aren’t yet quite strong enough to make any company do something really daring—like moving cars off the streets, and letting cyclists stay safe on the ground.

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