We've been talking a lot about autonomous vehicles, and in particular Waymo, on this blog. In my opinion, the safety records — which Waymo has published after driving more than 100 million driverless miles — already suggest that none of us should be driving cars anymore. Some or many of you will disagree with this statement, but there's a reason why car crashes are the number two cause of death for children and young adults in the US.
So not only is this a tech breakthrough and a profound city-building shift, but it's also a public health breakthrough. Here's a recent opinion piece published in the New York Times by Dr. Jonathan Slotkin, the vice chair of neurosurgery at the Geisinger Health System in Pennsylvania. I found this statement particularly interesting:
In medical research, there’s a practice of ending a study early when the results are too striking to ignore. We stop when there is unexpected harm. We also stop for overwhelming benefit, when a treatment is working so well that it would be unethical to continue giving anyone a placebo. When an intervention works this clearly, you change what you do.
Now the imperative:
There’s a public health imperative to quickly expand the adoption of autonomous vehicles. More than 39,000 Americans died in motor vehicle crashes last year, more than homicide, plane crashes and natural disasters combined. Crashes are the No. 2 cause of death for children and young adults. But death is only part of the story. These crashes are also the leading cause of spinal cord injury. We surgeons see the aftermath of the 10,000 crash victims who come to emergency rooms every day. The combined economic and quality-of-life toll exceeds $1 trillion annually, more than the entire U.S. military or Medicare budget.
Dr. Slotkin goes on to talk about some of the cities that are pushing back against AV adoption, or simply erecting barriers, namely Washington, D.C. and Boston. That's too bad. This is a decision that can be easily guided by data: Which is the safest option for the greatest number of people? Just do that. Dr. Slotkin gets it right: "policymakers need to stop fighting this transformation and start planning for it."
Following my recent post about the largest cities in the world (from 100 to 2015 CE), a number of you rightly pointed out that the data looked questionable. Where, for example, is Shanghai in this latest list of largest cities? So I think it's important that I do a follow-up post.
There are a number of nuances to consider when trying to measure urban populations. Perhaps the two most obvious are the geographic extent of each city (i.e. what urban boundary do you use) and the number of people living in informal settlements.
The UN recently estimated that there are some 1 billion people living in slums or informal settlements. That represents nearly a quarter of the world's urban population, which is a staggering number and a pressing global need. We desperately need more housing.
When it comes to measuring the size of an urban agglomeration, most of the studies that I have seen tend not to focus on municipal boundaries ("city propers") or metropolitan areas. The former is often based on arbitrary political boundaries and the latter often contains undeveloped rural land.
So for the purposes of this post, I'm going to go with Demographia's definition of "built-up urban area." They define this as being a continuously built-up area with one labor market and with no rural land. In their view, the world is either urban/built-up or rural. The built-up part is the lighted area that you would see on a nighttime satellite photo.
Given this definition, there are a number of interesting fringe cases. For example, contiguous/adjacent urban areas with more than one labor market get split up into multiple ones. This is the case in the US with the northeastern "megalopolis" that runs from Boston to Washington.
Conversely, if adjacent urban areas share a labor market and are linked together by similar commuting flows, then they get grouped into one urban area. This might be the case even if the area(s) straddle a national border. In this particular case, the free movement of people and goods would be another prerequisite.
Well here are some interesting figures (via MIT Technology Review):
In the past two decades, about 400 million people moved into China's cities -- so more than the entire population of the United States
We've been talking a lot about autonomous vehicles, and in particular Waymo, on this blog. In my opinion, the safety records — which Waymo has published after driving more than 100 million driverless miles — already suggest that none of us should be driving cars anymore. Some or many of you will disagree with this statement, but there's a reason why car crashes are the number two cause of death for children and young adults in the US.
So not only is this a tech breakthrough and a profound city-building shift, but it's also a public health breakthrough. Here's a recent opinion piece published in the New York Times by Dr. Jonathan Slotkin, the vice chair of neurosurgery at the Geisinger Health System in Pennsylvania. I found this statement particularly interesting:
In medical research, there’s a practice of ending a study early when the results are too striking to ignore. We stop when there is unexpected harm. We also stop for overwhelming benefit, when a treatment is working so well that it would be unethical to continue giving anyone a placebo. When an intervention works this clearly, you change what you do.
Now the imperative:
There’s a public health imperative to quickly expand the adoption of autonomous vehicles. More than 39,000 Americans died in motor vehicle crashes last year, more than homicide, plane crashes and natural disasters combined. Crashes are the No. 2 cause of death for children and young adults. But death is only part of the story. These crashes are also the leading cause of spinal cord injury. We surgeons see the aftermath of the 10,000 crash victims who come to emergency rooms every day. The combined economic and quality-of-life toll exceeds $1 trillion annually, more than the entire U.S. military or Medicare budget.
Dr. Slotkin goes on to talk about some of the cities that are pushing back against AV adoption, or simply erecting barriers, namely Washington, D.C. and Boston. That's too bad. This is a decision that can be easily guided by data: Which is the safest option for the greatest number of people? Just do that. Dr. Slotkin gets it right: "policymakers need to stop fighting this transformation and start planning for it."
Following my recent post about the largest cities in the world (from 100 to 2015 CE), a number of you rightly pointed out that the data looked questionable. Where, for example, is Shanghai in this latest list of largest cities? So I think it's important that I do a follow-up post.
There are a number of nuances to consider when trying to measure urban populations. Perhaps the two most obvious are the geographic extent of each city (i.e. what urban boundary do you use) and the number of people living in informal settlements.
The UN recently estimated that there are some 1 billion people living in slums or informal settlements. That represents nearly a quarter of the world's urban population, which is a staggering number and a pressing global need. We desperately need more housing.
When it comes to measuring the size of an urban agglomeration, most of the studies that I have seen tend not to focus on municipal boundaries ("city propers") or metropolitan areas. The former is often based on arbitrary political boundaries and the latter often contains undeveloped rural land.
So for the purposes of this post, I'm going to go with Demographia's definition of "built-up urban area." They define this as being a continuously built-up area with one labor market and with no rural land. In their view, the world is either urban/built-up or rural. The built-up part is the lighted area that you would see on a nighttime satellite photo.
Given this definition, there are a number of interesting fringe cases. For example, contiguous/adjacent urban areas with more than one labor market get split up into multiple ones. This is the case in the US with the northeastern "megalopolis" that runs from Boston to Washington.
Conversely, if adjacent urban areas share a labor market and are linked together by similar commuting flows, then they get grouped into one urban area. This might be the case even if the area(s) straddle a national border. In this particular case, the free movement of people and goods would be another prerequisite.
Well here are some interesting figures (via MIT Technology Review):
In the past two decades, about 400 million people moved into China's cities -- so more than the entire population of the United States
With these definitions out of the way, below is another stab at sharing an accurate list of the world's largest megacities or built-up urban areas. This is one is by Demographia and there are a number of key changes compared to the last one I shared. Shanghai now features in the top 10. But Lagos drops down to number 20, which remains a bit of a question mark for me.
For a copy of Demographia's full report, click here. It looks at all urban areas with a population greater than 500,000 people (total is 985). Of course, if any of you have any other data sources that you think I should take a look at, feel free to share them in the comment section below.
By 2035, about 70% of China's entire population is expected to be urban (up from 60% today and up from 30% two decades ago)
To accommodate this scale of growth, China's national urban development approach has shifted to something that now revolves around city clusters, or megalopolises (term coined by French geographer Jean Gottmann back in the 1950s to describe the Boston-Washington corridor in the Northeastern US)
By 2035, there are expected to be five major city clusters (see above)
One of the reasons for this is to improve cooperation across the various clusters -- less competition and less redundancy
But it's also about creating smaller more manageable cities -- is this what one needs to do after a certain scale, go polycentric?
To service these clusters, China is rolling out a network of 16 new high-speed rail lines
By 2035, China expects to have 200,000 kilometers of rail, with a third of it being high-speed -- assuming this happens, China will be home to 60% of the world's high-speed rail coverage
Current cost estimates for the construction of this network comes out to about US$150 million per kilometer
1-2-3 Rule: The plan is that everyone should be able to get around a city within 1 hour; a city cluster within 2 hours; and travel between the country's clusters inside of 3 hours
China is building.
With these definitions out of the way, below is another stab at sharing an accurate list of the world's largest megacities or built-up urban areas. This is one is by Demographia and there are a number of key changes compared to the last one I shared. Shanghai now features in the top 10. But Lagos drops down to number 20, which remains a bit of a question mark for me.
For a copy of Demographia's full report, click here. It looks at all urban areas with a population greater than 500,000 people (total is 985). Of course, if any of you have any other data sources that you think I should take a look at, feel free to share them in the comment section below.
By 2035, about 70% of China's entire population is expected to be urban (up from 60% today and up from 30% two decades ago)
To accommodate this scale of growth, China's national urban development approach has shifted to something that now revolves around city clusters, or megalopolises (term coined by French geographer Jean Gottmann back in the 1950s to describe the Boston-Washington corridor in the Northeastern US)
By 2035, there are expected to be five major city clusters (see above)
One of the reasons for this is to improve cooperation across the various clusters -- less competition and less redundancy
But it's also about creating smaller more manageable cities -- is this what one needs to do after a certain scale, go polycentric?
To service these clusters, China is rolling out a network of 16 new high-speed rail lines
By 2035, China expects to have 200,000 kilometers of rail, with a third of it being high-speed -- assuming this happens, China will be home to 60% of the world's high-speed rail coverage
Current cost estimates for the construction of this network comes out to about US$150 million per kilometer
1-2-3 Rule: The plan is that everyone should be able to get around a city within 1 hour; a city cluster within 2 hours; and travel between the country's clusters inside of 3 hours
China is building.
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