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.

Cover photo by Jack Nagz on Unsplash

I cover a lot of different topics on this blog. It's hard to write daily for a decade and not meander every now and then. But generally speaking, I do try and keep this forum focused on things that are related to city building -- real estate, housing, design, transportation, etc. And I do try and share some of the things that I have learned (and the mistakes that I have made) since I started working in real estate development back in 2007.

But we all have limits, and different perspectives are vital for solving problems. So I'd really like to introduce more Q&A features on this blog, similar to this recent one that I did with structural engineer, James Cranford. If this sounds interesting to any of you, please reach out. I'm open to anyone who touches the built environment: architects, artists, planners (private or municipal), lenders, furniture designers, bollard manufactures ... you name it!

Image: Jason Adam Katzenstein

On July 1 of this year, a new California bill, called the "Affordable Housing and High Road Jobs Act of 2022", will go into effect. And the goal of this legislation is to significantly increase the supply of new homes in the state by allowing multi-family construction on lands that are currently zoned for commercial uses.

On some level, it is of course curious that there even needs to be this bill. Because what we are effectively saying is, "hey, we should allow people to build a mix of uses on our main streets and with high enough densities that we might actually be able to support transit." Why was this not always the case? (Rhetorical question.)

In the words of architect and planner Peter Calthorpe, who was recently interviewed here in ArchDaily, this is a "landmark piece of legislation" that has "received very little attention." So that's why we're talking about it today.

Calthorpe was actively involved in crafting this legislation, and his work apparently started with different scenario land-use models. The first experiment looked at a 43-mile stretch of El Camino running from San Francisco to San Jose (pictured below). And what they found was that this one strip alone could accommodate somewhere around 250,000 new infill homes.

To put this into context, the state of California is currently building about 140,000 new homes each year, through a roughly equal (1:1) split of multi-family and low-rise single-family. Already this represents a shift, as supply used to be slanted (3:1) toward low-rise. (I don't know when exactly this was the case, but Calthorpe mentions the figure in his interview.)

Moving on from El Camino, Calthorpe and his team then ran a similar exercise for the five-county inner Bay area. And here they found that some 700 miles of commercial land could produce up to 1.3 million multi-family homes at "reasonable densities." This was then expanded to the entire state of California and the number increased to 10 million new homes.

Of course, as we have talked about before on this blog, not all of this land might actually be feasible for development. Sometimes the math doesn't work even at a zero land cost; you might need a negative land cost in order to pencil a new development. Meaning, you might need to be paid, perhaps through some sort of subsidy.

So what Calthorpe and the team did was use MapCraft to quickly run development feasibilities on the above sites. They had it run 6 different pro formas using local rents, construction costs, city fees, and so on. And what they determined was that this 10 million number drops down to 2 million when you apply the economic realities of the world.

As a disclaimer, I'm not at all familiar with MapCraft. But I'm going to take this number at face value and say that this is still a lot of new homes. And this is what people are hoping for come July 1 of this year.

Image: HDR / Peter Calthorpe

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.

Cover photo by Jack Nagz on Unsplash

I cover a lot of different topics on this blog. It's hard to write daily for a decade and not meander every now and then. But generally speaking, I do try and keep this forum focused on things that are related to city building -- real estate, housing, design, transportation, etc. And I do try and share some of the things that I have learned (and the mistakes that I have made) since I started working in real estate development back in 2007.

But we all have limits, and different perspectives are vital for solving problems. So I'd really like to introduce more Q&A features on this blog, similar to this recent one that I did with structural engineer, James Cranford. If this sounds interesting to any of you, please reach out. I'm open to anyone who touches the built environment: architects, artists, planners (private or municipal), lenders, furniture designers, bollard manufactures ... you name it!

Image: Jason Adam Katzenstein

On July 1 of this year, a new California bill, called the "Affordable Housing and High Road Jobs Act of 2022", will go into effect. And the goal of this legislation is to significantly increase the supply of new homes in the state by allowing multi-family construction on lands that are currently zoned for commercial uses.

On some level, it is of course curious that there even needs to be this bill. Because what we are effectively saying is, "hey, we should allow people to build a mix of uses on our main streets and with high enough densities that we might actually be able to support transit." Why was this not always the case? (Rhetorical question.)

In the words of architect and planner Peter Calthorpe, who was recently interviewed here in ArchDaily, this is a "landmark piece of legislation" that has "received very little attention." So that's why we're talking about it today.

Calthorpe was actively involved in crafting this legislation, and his work apparently started with different scenario land-use models. The first experiment looked at a 43-mile stretch of El Camino running from San Francisco to San Jose (pictured below). And what they found was that this one strip alone could accommodate somewhere around 250,000 new infill homes.

To put this into context, the state of California is currently building about 140,000 new homes each year, through a roughly equal (1:1) split of multi-family and low-rise single-family. Already this represents a shift, as supply used to be slanted (3:1) toward low-rise. (I don't know when exactly this was the case, but Calthorpe mentions the figure in his interview.)

Moving on from El Camino, Calthorpe and his team then ran a similar exercise for the five-county inner Bay area. And here they found that some 700 miles of commercial land could produce up to 1.3 million multi-family homes at "reasonable densities." This was then expanded to the entire state of California and the number increased to 10 million new homes.

Of course, as we have talked about before on this blog, not all of this land might actually be feasible for development. Sometimes the math doesn't work even at a zero land cost; you might need a negative land cost in order to pencil a new development. Meaning, you might need to be paid, perhaps through some sort of subsidy.

So what Calthorpe and the team did was use MapCraft to quickly run development feasibilities on the above sites. They had it run 6 different pro formas using local rents, construction costs, city fees, and so on. And what they determined was that this 10 million number drops down to 2 million when you apply the economic realities of the world.

As a disclaimer, I'm not at all familiar with MapCraft. But I'm going to take this number at face value and say that this is still a lot of new homes. And this is what people are hoping for come July 1 of this year.

Image: HDR / Peter Calthorpe