
Let's add some historical context to yesterday's post about autonomous vehicles. As the regular non-autonomous version of cars started to infiltrate our cities in the early 20th century, largely following the creation of the mass-produced Ford Model T, there was a general view that cars were dangerous and a menace to cities. Arguably, not much has changed.
So in the 1930s, the Federal Housing Authority decided to publish a pamphlet explaining what street networks it thought were suitable for this new emerging car world and which street networks were not. The exact terms that they used were "bad" and "good", and here's what that looked like (taken from this CNU article):

The "bad" ones are largely how the US liked to design its cities before the arrival of the car. Some historic settlements, like Boston and Manhattan south of 14th street were based on different street logics, but as far back as the 1680s, William Penn had already started laying out a grid iron plan for Philadelphia. And in reality, this kind of street pattern goes all the way back to ancient cities.
However, when the car arrived, these grid iron plans were thought to offer an inadequate amount of separation between people and machine. The solution was to optimize around the car and introduce a clear hierarchy of different streets. Big streets for moving cars quickly, and smaller streets, like cul-de-sacs, for people to live on.
These "good" examples, of course, represent the modern suburb. But we now recognize that these types of street networks are unequivocally terrible for walkability, the environment, public health, social equity, and a whole host of other things. I mean, look at this extreme example of two suburban homes in Orlando whose backyards adjoin but are technically separated by 7 miles and a 20-minute drive!
My point with all of this is that, for many/most at the time, this was progress. Cars were the future and there was optimism about the kind of freedoms and other benefits that they would bring to people. And this optimism is perhaps not all that different from what many people feel today, myself included, when it comes to autonomous vehicles.
So on the one hand, you could point to the car and say, "look at all the damage that this thing did to our cities. Let's not do that again. Autonomous vehicles must be stopped." But that's akin to wishing the car was never invented. Another option is to point to the negative externalities associated with the car and say, "look at what we've done. We can do better. Let's make our cities better."
Positive change, no matter how late, is always a possibility.


One of the small things that I liked about living in Philadelphia was the rational way in which street addresses tended to work.
Here’s an example.
Let’s say you wanted to go to Brooks Brothers in Center City and you discovered that the address was 1513 Walnut Street (which it is).
By looking at the first two numbers, you would immediately know that the store sits between 15th Street and 16th Street on Walnut.
If the address you were given was 1601 Walnut Street, you would know that your destination is now between 16th Street and 17th Street, but probably right at 16th.
You would also know that the numbered streets run north-south and the streets named after trees run east-west. (Of course, not all of the east-west streets are named after trees.)
No need to pull up the Google machine.
All of this stems from William Penn’s incredibly rational 17th century grid plan for the city – one of the first examples in North America.
If you’re interested in grids, you may also enjoy this post from last year: The spatiotemporal hierarchy of urban form.
Photo by Jay Dantinne on Unsplash