Bloomberg recently interviewed the outgoing head of San Francisco's transportation agency -- Jeffrey Tumlin -- about the impact that self-driving cars have had on the city. Along with maybe Phoenix, San Francisco has the most direct experience. Robotaxis have already been operating in the city for four years.
It's an interesting interview. On the one hand, robotaxis have, according to Tumlin, gotten better than most humans at "seeing" and predicting the behaviours of pedestrians. They offer slow and steady law-abiding rides, which is arguably not how must humans drive. This is a safety improvement.
But on the other hand, robotaxis still represent a fundamentally inefficient use of roadway space. They take up just as much space as human-operated cars, but importantly, they offer a less frustrating driving experience. Meaning they tend to induce demand, much like ride-hailing platforms.
In a 2018 study by San Francisco County, they found that roughly 50% of the increase in vehicle miles traveled in the region was due to Uber and Lyft. So not surprisingly, there are important things that will need to be figured out as robotaxis continue to spread across our cities.
I also find the comparison in the interview between San Francisco and Phoenix to be particularly interesting. The former is walkable. The latter is not. And this seems to be creating a different experience with self-driving cars because robo or not, in Phoenix, traveling by car is pretty much the only option.
For the full interview, click here.
My partner Kieran sent me this chart this morning:
It is a summary of the average weekday miles traveled by adults in private vehicles, including taxis and ride-hailing vehicles, for the 50 largest metro areas in the US (data is from the fall of 2023). At the top of the list with the most miles traveled is Raleigh, and at the bottom of the list with the fewest miles traveled is, not surprisingly, New York.
The other cities on the bottom of this list probably won't surprise you either. But it's a good reminder of how built form determines our mobility choices. If you look up which US cities have the highest population densities and the most compact built forms, I think you'll generally find that it mirrors what you're seeing here.
When we build next to transit, we often call this transit-oriented development.
What’s interesting about this moniker is that it implies we’re doing something a little special — something out of the ordinary. And I guess that makes sense because, in many cities, it is often out of the ordinary.
That’s why you don’t hear people at real estate conferences saying, “check out this new cutting edge car-oriented development that our firm is developing.” That doesn’t need to be specified.
But at the end of the day, I’m not sure how special transit-oriented development really is; it’s basically just urban development. Meaning, you put density on top of and next to transit stations and then more people take transit. That’s how this works.
On that note, here is an interesting study from the School of Cities that looked at Toronto’s transit network and how the populations around each station have changed (or not changed) between 1996 and 2021 (census data).
If you look at the various transit lines, you’ll see that, in some cases, like downtown, we have added a lot of new transit-oriented development. This is good. Populations increased.
But in many/most other cases, populations remained flat; or worse, they declined. This is a serious problem, and it shows how land use restrictions are forcing us to underutilize our existing transit assets.
Maybe what we need to do is stop thinking about transit-oriented development as something special, and instead remind ourselves that this is standard operating procedure. It’s just what you do next to transit.
Thanks to Sam Kulendran for sharing the above study with me.