Congestion pricing—the implementation of high tolls to keep cars out of congested downtown areas—is one of the most effective ways to reduce traffic and emissions. Zurich's plan goes above and beyond that, using a network of sensors to track the number of cars that enter its downtown and prevent more cars from entering until congestion has subsided.
As detailed in a new piece by Streetfilms, Zurich's traffic control concept includes the installation of induction loop sensors (similar to what we see at stoplights in the U.S.) that track the number of cars on streets.
These sensors (about 4,500 now) monitor how many cars are circulating in the city center and can communicate with signaling technology to lengthen (or shorten) lights. But when traffic gets too heavy, the sensors go a step further, actually preventing cars from entering the downtown area.
Of course, Zurich also has an incredibly robust transit system (some claim the best in the world) and car ownership in the city is at about 50 percent. So many people have and use the wide variety of options to get into town. However there are complaints that the system favors pedestrians and public transit too much. Plus, the system does create congestion outside the city, which isn't healthy for those residents.
With cities like DC toying with adding congestion pricing, they'll also be adding tech tools to measure the number of cars driving into the congestion zone, but this is more so they can jack up the rates when the city is "full." Actually preventing cars from entering the city center is far more radical, and while it seems to be largely embraced by the Swiss, this one-in-one-out policy would probably not go over as well in the U.S. Of course, it's debatable that any city (perhaps besides New York) has the public transportation infrastructure to support a similar system.
All images via Streetfilm's Zurich video