We live in a world marching straight toward gridlock. In 2007, the share of people living in cities crossed 50% for the first time. By 2050, more than 66% of humanity will live in urban areas. At the same time, the number of cars sold keeps rising. In just the last decade, there has been a 40% jump, to more than 93 million vehicles sold worldwide in 2016.
Congestion is our tragedy of the commons. We get a very expensive resource, road usage, nearly for free, and as a result binge on it. Typically, cities and governments try to deal with congestion by building more roads, even though it was shown more than 20 years ago that adding space for cars typically ends up causing more traffic. The toll congestion exacts, from lost productivity to accidents to air pollution that contributes greatly to climate change, is huge. By 2030, the cost of congestion is expected to reach $186 billion per year in the U.S. alone.