In their California study, Garrick and Marshall eventually realized the safest cities had an element in common: They were all incorporated before 1930. Something about the way they were designed made them safer. The key wasn’t necessarily that large numbers of bikers produced safer cities, but that the design elements of cities that encouraged people to bike in places like Davis were the same ones that were yielding fewer traffic fatalities.
These cities were built the old way: along those monotonous grids. In general, they didn’t have fewer accidents overall, but they had far fewer deadly ones. Marshall and Garrick figured that cars (and cars with bikes) must be colliding at lower speeds on these types of street networks. At first glance such tightly interconnected communities might appear more dangerous, with cars traveling from all directions and constantly intersecting with each other. But what if such patterns actually force people to drive slower and pay more attention?
A lot of people feel that they want to live in a cul-de-sac, they feel like it’s a safer place to be,” Marshall says. “The reality is yes, you’re safer – if you never leave your cul-de-sac. But if you actually move around town like a normal person, your town as a whole is much more dangerous.”
This is the opposite of what traffic engineers (and home buyers) have thought for decades. And it’s just the beginning of what we’re now starting to understand about the relative advantages of going back to the way we designed communities a century ago.
Taken from Debunking the Cul-de-Sac