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.
This data is from 2019, but I imagine that things would look pretty similar today and that it might even be a little more pronounced. The dataset from the above article looked at how many people have cars in a given area (a darker dot = fewer cars) and then plotted this against population density and income per capita.
Here's what that looks like for the regions of New York, Boston, Los Angeles, and Houston (data from 2013 to 2017):
I haven't seen this sort of data before and it's an interesting way of looking at job access, transit connectivity, and overall built form:
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.
This data is from 2019, but I imagine that things would look pretty similar today and that it might even be a little more pronounced. The dataset from the above article looked at how many people have cars in a given area (a darker dot = fewer cars) and then plotted this against population density and income per capita.
Here's what that looks like for the regions of New York, Boston, Los Angeles, and Houston (data from 2013 to 2017):
I haven't seen this sort of data before and it's an interesting way of looking at job access, transit connectivity, and overall built form:
What is fascinating about these charts is that they show two different correlations. In dense and transit-rich cities such as New York and Boston, car usage is most closely linked with population density and not with income. The dark dots form a horizontal line near the top.
However, in the case of Los Angeles and Houston, car usage is instead most closely linked with income and not with population density. The dark dots form a vertical line near the left -- the lowest income per capita.
So what does this tell us?
It tells us that if you design a city to broadly require a car, then you are likely to sort people based on those that can afford a lot of car and those that cannot. On the other hand, if you design a city around transit, then you are likely to instead create a place where both the rich and poor get around in similar ways.
There is also evidence that the latter is being increasingly viewed as more desirable. 2017 was the first year in the US where high-income young people (ages 26 to 33) drove less than low-income young people. Presumably these high-income people had choices, and so I tend to view this as a preference.
As a whole, this is surely a good thing for our cities. But now I think we need to be careful not to allow density and walkability to become the new luxury that only the rich can afford.
The above is a table from New Geography (using data from the University of Minnesota). And what it shows is how many more jobs, across the US, can be accessed within a 30-minute commute by car versus by transit. For example, what this data tells us is that, on average across the US, there are about 56x more jobs that can be quickly accessed by car versus by transit.
But there is also huge variation across the 50 largest cities in the US. On the top end is Detroit, where there about 130x more jobs that can be accessed by car (again within 30 minutes). This isn't at all surprising. Also not surprising is the fact that New York is on the lowest end with only 5.6x as many car-versus-transit jobs. This is one of the reasons why I spoke yesterday about NYC being such an ideal candidate for something like NYC 25x25.
What a lower number tells us is that the city is far less reliant on personal vehicles and almost certainly has a higher urban density. That's why you see cities like New York, San Francisco, Boston, and Chicago near the top of this list. And in my opinion, this is where you want to be. The goal should be to minimize this multiple.
I haven't seen a dataset like this before, but I'm now curious to see how it varies globally. It feels like something that more of us should be monitoring. Because we know that there are strong links between jobs access and the overall economic performance of a city.
What is fascinating about these charts is that they show two different correlations. In dense and transit-rich cities such as New York and Boston, car usage is most closely linked with population density and not with income. The dark dots form a horizontal line near the top.
However, in the case of Los Angeles and Houston, car usage is instead most closely linked with income and not with population density. The dark dots form a vertical line near the left -- the lowest income per capita.
So what does this tell us?
It tells us that if you design a city to broadly require a car, then you are likely to sort people based on those that can afford a lot of car and those that cannot. On the other hand, if you design a city around transit, then you are likely to instead create a place where both the rich and poor get around in similar ways.
There is also evidence that the latter is being increasingly viewed as more desirable. 2017 was the first year in the US where high-income young people (ages 26 to 33) drove less than low-income young people. Presumably these high-income people had choices, and so I tend to view this as a preference.
As a whole, this is surely a good thing for our cities. But now I think we need to be careful not to allow density and walkability to become the new luxury that only the rich can afford.
The above is a table from New Geography (using data from the University of Minnesota). And what it shows is how many more jobs, across the US, can be accessed within a 30-minute commute by car versus by transit. For example, what this data tells us is that, on average across the US, there are about 56x more jobs that can be quickly accessed by car versus by transit.
But there is also huge variation across the 50 largest cities in the US. On the top end is Detroit, where there about 130x more jobs that can be accessed by car (again within 30 minutes). This isn't at all surprising. Also not surprising is the fact that New York is on the lowest end with only 5.6x as many car-versus-transit jobs. This is one of the reasons why I spoke yesterday about NYC being such an ideal candidate for something like NYC 25x25.
What a lower number tells us is that the city is far less reliant on personal vehicles and almost certainly has a higher urban density. That's why you see cities like New York, San Francisco, Boston, and Chicago near the top of this list. And in my opinion, this is where you want to be. The goal should be to minimize this multiple.
I haven't seen a dataset like this before, but I'm now curious to see how it varies globally. It feels like something that more of us should be monitoring. Because we know that there are strong links between jobs access and the overall economic performance of a city.
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