The Case for the Slow City

Speed kills. That's especially true if you're a pedestrian unlucky enough to get hit by a car. If the car is moving at 33 mph. (53 km./hr.), you have a 50 percent chance of being seriously injured. At 25 mph. (40 km./hr.), that falls to 25 percent. It doesn't seem like much of a difference in speed, but the energy of the impact depends on the square of the velocity, something that most people don't take into account when judging speed.

That's led to a "slow cities" movement to reduce traffic speeds and hence traffic injuries and deaths. There are other benefits, as discussed in this CityLab article.

Speed kills is a more abstract sense, too. Building urban roads that can handle a large number of vehicles traveling at 35 miles per hour and up means making them wider, with fewer curves. High-speed highways and street-level limited-access urban thoroughfares famously do a host of bad things to those who live nearby or underneath these big hostile barriers. What’s less discussed is what they’re doing to the people inside the cars. In his recent book Building and Dwelling, the planner and urban scholar Richard Sennett writes about how going faster in cities has lead urbanites to value “space” over “place.” 

The article ends by mentioning the possibility of autonomous vehicles, which would be much safer and easier to operate if they were running at a lower speed.