The area of Manhattan is 90km^2. The population is 1.62 million, double that of SF. The area of SF is 600km^2. So yes, while there is some theoretical limit to the population that could be fit into SF, we are not even remotely close to it.
We could triple the population of SF if we simply increased the density to that of Pune, a city with a small town feel that fits 2.5M people into 700km^2. (I.e., it's not remotely like Manhattan.) Pune has also experienced a tech boom and huge population growth, yet has not suffered from real estate issues the way SF does.
Unfortunately, your area for San Francisco is 80% water. The more relevant data of land area is more like 60 km^2 for Manhattan and 120 km^2 for San Francisco.
Edit: as a result, your comparison to Pune is significantly inaccurate. Indeed, Pune is only some 25% more dense than San Francisco, not three times as you suggest. This is easiest to check by looking at the "population density" figure on Wikipedia, but it's consistent with doing the relevant calculations yourself. (I checked.)
You seem to be correct - the area number you get by googling does include water. My mistake. I guess the ultimate limit of SF might indeed be only 2x or 3x Manhattan (Manhattan could be considerably more dense than it is).
Nevertheless, I do stand by the claim that Pune has handled population and economic growth well by building more housing, and is likely to continue doing so.
How is transportation and other city services there?
I have been listening to Econtalk episodes on urban growth[1][2] and apparently cities in the developing world experiencing quick expansion get completely clogged with traffic. The transaction costs are too high for developments to come to some agreement on providing city-wide transport. Some places don't have a proper sewage system, or rely on diesel power because they could not build an efficient power plant.
Pune has more traffic than it used to, but getting around is pretty easy. It's highly walkable, auto rickshaws are easy to find in most areas, and there is plenty of public transit (govt buses, privately owned 6 seaters). Many jobs also offer transport, jobs with western hours (read: call centers) in particular. Roads and flyovers are being built at a good clip - unlike the US, construction is pretty cheap and isn't paralyzed by red tape.
You don't actually need to provide city-wide transport. All you really need is demand for it - entrepreneurial types are pretty good at figuring out where it's needed. You do, however, need to avoid passing (or at least enforcing) laws against it.
I've heard New York is the only city in the US with excellent public transport. But yes, a proper underground metro requires a fair bit of planning and coordination, and if SF can't manage that then it will eventually end up like LA.
NYC's is on the order of Paris of London by way of comparison.
Washington D.C. (within the city) is a bit like a second tier European city, still quite good within the city, but D.C. has a huge metro area and it's spotty in the outer bits. There's lots of different jurisdictions that don't always integrate their bus systems well and building out the metro system has been slow going.
Portland has an excellent integrated system.
Chicago, Seattle, Boston, have decent, but limited systems.
However, even in places with almost no effective rail system, like Orlando, there's usually a comprehensive public bus system. They just run slowly, but they're relatively cheap, transfers are usually free and will get you close to where you want to go. Most public transport in L.A., for example, consists of the bus system.
I don't necessarily mean public transportation. Any transportation. Employer-provided buses, cabs, rickshaws, or even just roads where you can drive your own vehicle. Whatever is appropriate.
But the only thing that really works is underground carriage transport, because:
-It being underground means it's not in the way of everything and, more importantly, vice versa - it can go as fast as you want.
-It being carriage based means there's no coordination with other drivers. No queue dynamics, crossings or whatever. Transport happens in constant time, independent of the amount of passengers (within reasonable bounds).
I think rush hour travel on NYC's subway might put your "transport happens in constant time for grade separated trains" notion to the test. New York City's subway system is quite impressive, given that it's pushing 100 years old in many places and runs (nearly) 24/7/365, but the more crowded the subway gets -> the longer the doors take to close -> train headways become unevenly spaced -> queueing dynamics come into play. The latest "subway etiquette" ad campaigns from the operators specifically instruct riders to stand aside before boarding the train. [1] NYC rush hour is probably right on the edge of the "reasonable bounds" you are describing.
Most of the underground systems I have been on go pretty slow, and stop frequently. Pedal bike is the fastest way for me as long as you don't are willing to bend the rules (which in my opinion often make cycling more dangerous).
It's worth pointing out that the on-paper density of Manhattan is highly misleading. The daytime population of Manhattan on a weekday, including commuters and tourists, is 3.5-4 million people (versus about 1 million for San Francisco). The city is built to handle that amount of population, not the smaller resident-only population.
I was in Manhattan right after Sandy, when the trains were still not running, and it looked like a ghost town with just the 1.6 million residents there.
Comparison with Manhattan is unhelpful. I think better comparisons are Singapore and Tokyo. Bay area residents bristle st the idea of tall towers --specially given the geological faults running beneath. Given that, Tokyo's approach of midrises interspersed with highrises would probably be the best hope. We could at least double or triple the population in SF proper. It would help tremendously if surrounding cities also went on a construction binge to relieve pent up demand.
It helps Manhattan a lot that it has one of the world's best-engineered public transportation systems to connect it to the other boroughs and to Jersey.
The problem with construction booms in East and South Bay is that the transportation infrastructure in SFBA is barely keeping up with the population as-is, and however asymptotically it approaches "adequate" today, it is also one of the country's most poorly managed systems: it's underinvested, hemmed in by a dysfunctional political system, freighted with union, tenure, and retirement problems, and poorly maintained.
Comments
The area of Manhattan is 90km^2. The population is 1.62 million, double that of SF. The area of SF is 600km^2. So yes, while there is some theoretical limit to the population that could be fit into SF, we are not even remotely close to it.
We could triple the population of SF if we simply increased the density to that of Pune, a city with a small town feel that fits 2.5M people into 700km^2. (I.e., it's not remotely like Manhattan.) Pune has also experienced a tech boom and huge population growth, yet has not suffered from real estate issues the way SF does.
The secret? Our underpopulated areas look like this: https://pbs.twimg.com/media/B8cMeVTIMAEMyzk.jpg:large
Unfortunately, your area for San Francisco is 80% water. The more relevant data of land area is more like 60 km^2 for Manhattan and 120 km^2 for San Francisco.
Edit: as a result, your comparison to Pune is significantly inaccurate. Indeed, Pune is only some 25% more dense than San Francisco, not three times as you suggest. This is easiest to check by looking at the "population density" figure on Wikipedia, but it's consistent with doing the relevant calculations yourself. (I checked.)
You seem to be correct - the area number you get by googling does include water. My mistake. I guess the ultimate limit of SF might indeed be only 2x or 3x Manhattan (Manhattan could be considerably more dense than it is).
Nevertheless, I do stand by the claim that Pune has handled population and economic growth well by building more housing, and is likely to continue doing so.
How is transportation and other city services there?
I have been listening to Econtalk episodes on urban growth[1][2] and apparently cities in the developing world experiencing quick expansion get completely clogged with traffic. The transaction costs are too high for developments to come to some agreement on providing city-wide transport. Some places don't have a proper sewage system, or rely on diesel power because they could not build an efficient power plant.
[1] http://www.econtalk.org/archives/2015/01/alex_tabarrok_o.htm...
[2] http://www.econtalk.org/archives/2015/03/paul_romer_on_u.htm...
Pune has more traffic than it used to, but getting around is pretty easy. It's highly walkable, auto rickshaws are easy to find in most areas, and there is plenty of public transit (govt buses, privately owned 6 seaters). Many jobs also offer transport, jobs with western hours (read: call centers) in particular. Roads and flyovers are being built at a good clip - unlike the US, construction is pretty cheap and isn't paralyzed by red tape.
You don't actually need to provide city-wide transport. All you really need is demand for it - entrepreneurial types are pretty good at figuring out where it's needed. You do, however, need to avoid passing (or at least enforcing) laws against it.
(Here is a little bit on private sector mass transit in the US: http://projects.newyorker.com/story/nyc-dollar-vans/ Jersey City also had these, and they were vastly superior to public buses.)
I've heard New York is the only city in the US with excellent public transport. But yes, a proper underground metro requires a fair bit of planning and coordination, and if SF can't manage that then it will eventually end up like LA.
NYC's is on the order of Paris of London by way of comparison.
Washington D.C. (within the city) is a bit like a second tier European city, still quite good within the city, but D.C. has a huge metro area and it's spotty in the outer bits. There's lots of different jurisdictions that don't always integrate their bus systems well and building out the metro system has been slow going.
Portland has an excellent integrated system.
Chicago, Seattle, Boston, have decent, but limited systems.
However, even in places with almost no effective rail system, like Orlando, there's usually a comprehensive public bus system. They just run slowly, but they're relatively cheap, transfers are usually free and will get you close to where you want to go. Most public transport in L.A., for example, consists of the bus system.
I don't necessarily mean public transportation. Any transportation. Employer-provided buses, cabs, rickshaws, or even just roads where you can drive your own vehicle. Whatever is appropriate.
But the only thing that really works is underground carriage transport, because:
-It being underground means it's not in the way of everything and, more importantly, vice versa - it can go as fast as you want.
-It being carriage based means there's no coordination with other drivers. No queue dynamics, crossings or whatever. Transport happens in constant time, independent of the amount of passengers (within reasonable bounds).
I think rush hour travel on NYC's subway might put your "transport happens in constant time for grade separated trains" notion to the test. New York City's subway system is quite impressive, given that it's pushing 100 years old in many places and runs (nearly) 24/7/365, but the more crowded the subway gets -> the longer the doors take to close -> train headways become unevenly spaced -> queueing dynamics come into play. The latest "subway etiquette" ad campaigns from the operators specifically instruct riders to stand aside before boarding the train. [1] NYC rush hour is probably right on the edge of the "reasonable bounds" you are describing.
[1] http://web.mta.info/nyct/service/CourtesyCounts.htm#STEPASID...
Most of the underground systems I have been on go pretty slow, and stop frequently. Pedal bike is the fastest way for me as long as you don't are willing to bend the rules (which in my opinion often make cycling more dangerous).
It's worth pointing out that the on-paper density of Manhattan is highly misleading. The daytime population of Manhattan on a weekday, including commuters and tourists, is 3.5-4 million people (versus about 1 million for San Francisco). The city is built to handle that amount of population, not the smaller resident-only population.
I was in Manhattan right after Sandy, when the trains were still not running, and it looked like a ghost town with just the 1.6 million residents there.
Comparison with Manhattan is unhelpful. I think better comparisons are Singapore and Tokyo. Bay area residents bristle st the idea of tall towers --specially given the geological faults running beneath. Given that, Tokyo's approach of midrises interspersed with highrises would probably be the best hope. We could at least double or triple the population in SF proper. It would help tremendously if surrounding cities also went on a construction binge to relieve pent up demand.
It helps Manhattan a lot that it has one of the world's best-engineered public transportation systems to connect it to the other boroughs and to Jersey.
The problem with construction booms in East and South Bay is that the transportation infrastructure in SFBA is barely keeping up with the population as-is, and however asymptotically it approaches "adequate" today, it is also one of the country's most poorly managed systems: it's underinvested, hemmed in by a dysfunctional political system, freighted with union, tenure, and retirement problems, and poorly maintained.
Manhattan's population density is 27,502/km^2, SF's is 6898/km^2 by way of comparison.