December 11, 2017

Flying taxis and urban sprawl

We have made great progress when it comes to transportation technologies at the beginning of the 21st century. A lot of the things that were inconceivable in the past have become reality or close to reality recently, such as the high-speed rail (top speed 267mph), electric vehicle, autonomous vehicles, and Hyperloop (750mph).  Just when we are in awe of the fast-changing of the world, visionaries come up with more astonishing and provocative ideas: the flying taxi proposed by Uber (also called UberAIR or UberCopters), and the commercial space transportation proposed by Elon Musk.

UberAIR is a new form of urban transportation that entails sharing a helicopter ride with a few people through the Uber platform. The white paper presents a pretty detailed plan including the economic model, the safety & noise evaluation, and other operational details. It seems like a perfect proposal: the helicopters will even be propelled by electricity. One can imagine the attractiveness of flying over the congested highway at 160 mph with zero emissions.

I enjoy the fast evolution of urban transportation, but cannot help getting skeptical: are we pushing it too far? After all, history tells us when it comes to transportation the consequences need to be fully evaluated before a full explosion of adoption. Otherwise, once get into a trap it can be hard to legislate or build our way out of it. Take automobiles as an example, when they were invented and popularized initially, it was hard to see the downsides until the side-effects accumulated to a visible scale. And now, so much effort is reducing the impacts of cars, but there are still no few effective measures.  UberAIR seems green since it will create zero emissions, but there are other problems related to sustainability such as the social equity (what UberX is suffering from already) and costs (Uber has not provided details on fares). However, the most serious issue to me will be the induced urban sprawl, meaning “the expansion of human populations away from central urban areas into low-density, monofunctional and usually car-dependent communities”.

The story is pretty straight-forward. When people in a city can cover a long distance in a short time, they can choose to live far away from the city center and have a long commute, which leads to urban sprawl. Urban sprawl causes unwalkable neighborhoods and cannot provide the density required by public transportation, which causes people to drive even more. Even though UberAIR is a shared mode and has limited direct negative impact on the environment if the source of electricity is clean and renewable, it creates this chain effects (the following graph) that induce more driving activities, which causes more energy consumption and greenhouse gas emissions in the transportation sector.