Google's Traffic-Rerouting Experiment Shows Modest Success

Google's researchers have been working on a solution to reduce traffic congestion in cities across the US. They used Google Maps to reroute a small portion of drivers in 10 cities, including San Francisco and Los Angeles, over a period of six months. The goal was to evenly spread traffic down more corridors as drivers head to similar destinations.

The study found that this approach could reduce congestion by nudging up vehicle speeds by 2% on average on congested roads and shortening travel times by a modest 0.7%. Alexandre Bayen, a co-author of the study and director of UC Berkeley's Center for Information Technology Research in the Interest of Society, said that splitting traffic can reduce congestion locally and also reduce CO2 emissions.

The researchers used data from Google Maps to divert drivers onto alternate routes, with varying degrees of success. In cities like Los Angeles, where they targeted highways, driving speeds increased by about 4.6%. However, in most cities, the improvement was smaller, with speeds increasing by just 0.5% during peak times.

Michael Manville, a professor of urban planning at UCLA, noted that this approach can have unintended consequences. 'You can do this, but you cannot be too successful, because if you are too successful, then more people will start driving, and essentially you'll be back to ground zero,' he said.

The study suggests that Google has the power to unilaterally manipulate a city's traffic, raising questions about the role of navigation apps in shaping urban transportation. Bayen emphasized that drivers have the choice whether to follow Google's route recommendations or use another map app.