In my last post I offered a thesis:

Cities should plan roads, design streets, and regulate interfaces.

Most of us use the words “street” and “road” interchangeably, but we shouldn’t. The two serve distinct purposes, and in fact are at odds with each other. Cities work best when they have both roads and streets, and suffer when the two are fused into low-performing stroads.

This is one of the core ideas of Strong Towns so I’ll just briefly recap:

• A road is a dedicated path for moving vehicles from point A to point B as quickly and safely as possible.

• A street is the public space that connects individual properties and provides circulation through a neighborhood.

If you’d like to read a lot more words about the distinction, I think these two articles are the best (1, 2). But I think this is very easy to see with a few visual examples:

These are roads:

These are streets:

I suspect that most Americans, looking at these examples, may think “those roads are everywhere, but I’ve never seen a street like that.” They’re rare because we mostly stopped making new streets about 100 years ago, but we haven’t completely lost this art. Some more recent examples include Seaside, FL (circa 1981), Serene, GA (circa 2005), Culdesac Tempe, AZ (circa 2023).

The deeper difference

Now that we have a visual sense, we can see that roads and streets are fundamentally different elements of the city.

A road is a conduit. It’s infrastructure with a mechanical purpose, just like power lines or sewers. Roads are the economic links between places, we can’t live without them. This point is somehow both so obvious as to be banal, and yet under-discussed among urbanists.

Meanwhile, a street is primarily an interface, that usually (but not always) has a conduit embedded in it. Here’s an example:

This is Denver’s Gaylord Street as it usually operates:

And here’s the same street with its conduit closed:

Why it matters

In the last post I said that cities should plan roads, design streets, and regulate interfaces. Let’s unpack that further.

Plan

Planning is a big-picture exercise. Since roads are conduits, it makes sense to think of them from a top-down perspective: looking at the map, thinking about the places we want to connect, and finding paths for conduits between them.

I found this mid-century arterial plan for Seattle, which is a pretty good illustration of what planning looks like. The planners laid out roads through the region, spaced far apart, but close enough to create efficient circulation for people and goods through the region.

Of course, these same mid-century planners ruined these plans by intentionally concentrating commercial land use on the “roads” and using them for local access, resulting in the ineffective hybrid monstrosity of a stroad.

Design

Design is about the details that create a specific experience.

For our city streets, the paths in front of our homes, the paths that give us access to shops and services, our priority is not moving cars as fast as possible from A to B. The priority is safety, not having our kids run over by a stranger. After that, we care about conviviality, the street being an enjoyable place to walk our dogs, visit our neighborhoods, or get coffee with friends.

But for the last 80 years or so that’s not how cities have worked. Mid-century cities only thought about roads, and prioritized vehicular speed and volume everywhere. The result is an environment that’s all-conduit, no interface. And for residents in that environment, the only safe and practical way to travel is to drive everywhere… which means that cities quickly run into the Geometry Problem.

Changing the design is the answer. That means things like widening sidewalks, extending the curbs and/or raising the crosswalks to make crossing safer. It could mean narrowing lanes to reduce through traffic speed, or changing the number and alignment of lanes to improve safety. It could mean adjusting the street lighting, adding planters or artwork.

These two shorts from Ed Erfurt give a great illustration of what this looks like. Rather than thinking about lines between places, street design is about the place itself; about making the street safe, and then making it comfortable and convivial for everyone.

Street design has been something of a lost art for the last few generations, but it’s coming back. If you want to dig into the nerdy details, a great resource is NACTO’s Urban Street Design Guide.

Finally, lest anyone mistake this post as anti-car, I want to emphasize that when cities get this right they make life better for everyone using the road, including drivers. This can be hard to imagine, but I think this Not Just Bikes video really helps:

Regulate

The last bit of my thesis was that cities should regulate interfaces. I want to touch on that here briefly, and will explore it in more depth in the future.

In short, cities don’t own the private property abutting the street, and they can’t design all the buildings and their facades. But the way buildings attach to the street is the most important thing in determining how that street will work, and how it will feel.

Going back to the last post, I showed an example of a dead interface, a parking garage occupying about half a block:

Imagine plopping that parking garage onto a quarter of Gaylord Street. It would significantly damage the experience of the place, reducing the attractive power of the built environment, which would harm the businesses on the street and lower their economic value. Of course, those businesses do need parking, but how we provide that parking matters.

So going back to our goals for beneficial regulation, cities can minimize the negative externalities and maximize the positive externalities of development by regulating how buildings attach to the street.

There’s been a lot of work in this area in the last 25 years or so, largely under the label “Form Based Code.” One example I particularly like is Russ Preston’s Place Code (it’s worth watching his Ted Talk if you have a few minutes!).

But I have a major disagreement with the majority of prior art here. Almost all of it is conceived of as an addition to the zoning code, or possibly a remix of zoning. And I deeply, sincerely believe that zoning does more harm than good. We don’t need zoning! So what are we to do?

In the my next post I’ll sketch out an idea I have for a different approach. In the mean time, I’d love to hear your questions and ideas in the comments!