My street in Somerville, MA has a WalkScore (91) that's higher than the average score for New York city (89), yet every building in my neighborhood is detached and three stories tall. I have a back yard with grass. Not a big one, but it feels nothing like lower Manhattan. And I can walk or bike to literally everything I need in a given week.

People equate "crowded" and "ugly" with "walkable" when it's just not accurate. Being more green and more attractive is literally one of the components of being walkable, because people need to actually want to walk.

The GP's point was that we should look at extremes between super dense cities and super sparse cities, and Somerville fits nicely there.

It would also be illegal to build almost any of Somerville as it exists using current building codes, in Somerville. Discussion from a year and a half ago: https://news.ycombinator.com/item?id=11918230

I strongly suspect when people say that, they're thinking of the day time population of the tourist/business districts in those cities. The daytime population of Manhattan is nearly 4 million people, mostly concentrated below 130th street. The density is probably 200k-250k people per square mile. The resident population density is actually only 70,000 people per square mile. I was there after Hurricane Sandy, when the commuters and tourists were gone, and it was empty.

Here is a typical side street in Rogers Park Chicago: https://www.google.com/maps/@42.0103744,-87.6640436,3a,75y,2.... At 30,000 people per square mile, it's about double the average density of Tokyo.

Here's one of the newer business districts in Tokyo: https://www.google.com/maps/@35.6807167,139.7630674,3a,75y,9.... That area probably has way above the average population density of the city.

In my Brooklyn neighborhood the density feels fairly low (10-15 visible in the street). Green space isn't great for most but I happen to live two blocks from a park.

Many places in Manhattan also feel like this if they aren't business or nightlife heavy.

Interestingly, Chiyoda, the Tokyo ward in which the street view you provided is located, has the lowest population (by which I mean the `resident' population density) among all wards in central Tokyo[1]. I believe that this strongly supports your point that the `suffocating' parts of a city does not really have many people living there.

[1]: https://en.wikipedia.org/wiki/Special_wards_of_Tokyo#List_of...

And yet the most densely populated districts don't feel all that bad for the most part. Kwun Tong https://www.google.com.hk/maps/@22.3138909,114.2268051,3a,60... and Wong Tai Sin https://www.google.com.hk/maps/@22.3435765,114.1929784,3a,75... for example. But Mong Kok is a subdistrict in Yau Tsim Mong, famous for being the most densely populated place in the world.. AND it's a shopping district too, with huge influx after working hours. https://www.google.com.hk/maps/@22.319367,114.1699535,3a,75y...

Unrelated: it's unclear to me how self-driving cars can help pollution. They're a solution to the problem of the high cost of labor, and not much else. If anything, self-driving cars will make it cheaper for everyone to ride cars everywhere, and so people will more often ride cars everywhere, and more pollution will be the result.

100% agree. I much prefer to live in a dense, urban, walkable area, but most built environments that satisfy these criteria violate modern zoning regulations.

So, the USA's supply of pleasant, dense environments is dwindling because every time an olde/walkable area revitalizes enough to attract new development, that new development must comply with modern zoning, and kills the thing that that makes the area attractive.

It's thoroughly frustrating.

Most of them are part of old cities that are past their prime in economic vitality, so those areas don't have the same liveliness as what you might get in downtown Boston. (I used to work for a company based there, and would spend hours walking around at night.)

I'd recommend Pittsburgh for walkability, too. It's one of the most delightful cities I've wandered around recently.

Unfortunately, even Boston, Pittsburgh, NYC, and the lesser-known but walkable/dense areas are pretty unappealing when compared to some cities in south/central america and Europe, that were built before cars took over everything.

I suspect once a few large cities go bankrupt and cannot enforce their zoning regulations, new construction will move in the direction of rational density again.

This said, the only reason why Hoboken and many other walkable cities can get public-support for being so walkable (and encouraging city planning as such) is the ample public-transit options.

This leads to no need for having a car which leads to most people not having one which leads to most people preferring walkable versus drivable. It's kind of a chicken-and-egg problem.

Portions of Seattle are very walkable (From the International District going north, quite a few miles), and individual parts of Chicago are walkable. Heck there are 2 or 3 mile stretches of San Diego are walkable (there might be more than that, I only spent a week there!)

Seattle, on the other hand, is a city where I’ve never really needed a car no matter where I lived or worked. I think that part of the lifestyle is brilliant. I have a car, but the battery goes dead between usages as often as not.

Seattle has plenty of walkable parts, but I grew up in a working class suburban neighborhood within the city where driving to the store was most certainly necessary.

Some individual portions of Chicago are very walkable. Likewise with some small bits of San Diego, though you are right, not as good as European cities.

The entire city is only 7 miles wide, so about half the city is within a 30 minute walking radius.

People want the best of all worlds. I want to own 100 acres (for my pet goats - even though I don't have the time to care for them I want them). I want my kid's school to be a most 200 meters from my front door (with a playground). I want my office, church, a dozen restaurants, and 30 other retail stores to be at most 500 meters from my front door. I'm not rich enough to afford that though so I have to compromise. Even if I was that rich, it is not possible for more than 2 people rich enough to afford that to live within 1000 meters of each other, and to support that requires thousands of not rich people living in 1000 meters.

People will choose a walkable neighborhood when they think it is a good compromise. Some valuable large livestock more than others and so will be late to move to the walkable city. Others want to spend their free time at the theater and will move to the walkable neighborhood early just because it is the fastest way to bed after the late night show. Most people are not so into either choice that one answer is obvious.

If you want a walkable neighborhood to work you need to fix the local schools. At least in the US most walkable neighborhoods are old areas of town where the schools are bad, those who want children feel compelled to move to the suburbs and the car lifestyle just because of how much better the schools are.

If you want walkable neighborhoods you need to fix zoning so that it is possible for them to happen. Strongtowns has a lot of analysis of what makes it possible - there are thousands of subtle things required, heavy handed efforts tend to leave a lot of the subtle problems in place.

We already have effectively self-driving cars with Uber and other car-sharing services, and all you need to do is go to SFO's departure level during peak travel times to see the traffic havoc that self-driving cars will bring -- too many cars and not enough curb space to drop off/pick up everyone.

When self-driving cars are cheap and plentiful then downtown streets will look the same -- self-driving cars will more than double car traffic since instead of 200 employees driving to work and parking into the parking garage (making one trip), now 1000 employees will be dropped off by their self-driving car, which will then have to drive away to park or look for the next passenger, making a second trip on already crowded streets.

With inter-car communication, there won't be any confusion about where each car intends to go. No long waits for an opening.

Car design will push towards passenger comfort, and no longer towards "power" and "handling". This could mean smaller cars overall. 1-2 passenger vehicles could be common.

Yeah, it's definitely far down the road, and there will be a lot of forces that'll make it difficult to reach, but I think self driving cars are a chance to make things better.

How does a self-driving car predict the unexpected? Braking distance of a 30mph car is 45 ft (ignoring reaction time) so anything that happens less than 45 feet in front of a self-driving car is going to need evasive action. On a busy street with cars in all lanes, the self-driving car is going to need to decide whether to hit the object (which could be a person darting across the street), or swerve into the car next to it.

With an intelligent mesh the emergency lane abort order will propagate from one to many within the local area and a standard algorithm will determine what each traveling vehicle must do as they all react at the same time to avoid the intruding objects and bring energy in play to a minimum, hopefully zero, value in the affected area.

At the same time emergency response services would automatically be notified as well.

I don't understand? A pedestrian steps in front of a 30mph self driving car that's 20 feet away. There's a sidewalk to the right and oncoming traffic to the left.

The car needs 45 feet to stop, so it's going to strike the pedestrian. Which I assume you recognize this since you said EMS will be called.

You may think it's unlikely that a pedestrian will step right in front of a car, but wait until pedestrians are trained that the car will always stop for them.

if a car were to drive as if every thing in its vicinity has the potential to move rapidly in front of the car, and hence it takes precautions for all potential accidents, it can't be moving very fast can it? if it is traveling on a busy street with a lot of vehicular traffic and pedestrians on the sidewalk, must it take precautions for each and every vehicle and person around it? how fast can such a self driving car possibly go, if this were to be the case?

I think it's possible that self driving cars could increase total driving like you explain, but i think it's also possible that they will drive down car ownership. Once you pay primarily based on usage (parking, insurance, depreciation are mostly fixed costs), you are more likely to drive sparingly.

A walkable, pro-self-driving-car city could also theoretically tax self-driving-car rides to offset environmental impact.

Dense cities will most likely restrict access to personal cars by a lot (using congestion fees or whatever), that's why I think that self driving cars will bring down the number of cars in the city.

Well, d--b said "both noise and air". Drivers can contribute a fair amount of noise in busy cities when they get irate and lay on the horn...

Tokyo is not a super dense city like New York. It has half the urban density as New York and doesn't even show up in the top 20 most-dense cities.

You also cannot put Los Angeles and Brasilia together. Brasilia has 1/8th the urban density of Los Angeles. Brasilia might as well be a suburb.

Furthermore, I am not sure how you are defining success but population and even GDP are not guaranteed measurements of a successful cities. A city can be both populous and miserable, such as Beijing, or economically insignificant and happy, such as San Luis Obispo, CA. So I would reconsider your claim... in truth, the happiest cities are among the most walkable.

Not all of Tokyo looks like Shibuya Crossing! Do a Google search for "Tokyo residential neighborhood". You'll find mostly two- or three-story buildings. The main difference? Streets are extremely narrow by North American standards and represent alleyways. This sort of development is what urbanists describe with the buzzword "human-scale".

They are both successful in growth for different reasons, but their density was determined by geography, not by 'what people enjoy'.

But whether people choose to live in them is determined by what people enjoy.

People tend to stay in the area they were born.

People tend to stay near their family.

People tend stay were they can find work.

People can't always afford to just up and move.

Not everyone is living on a six figure salary with a slew of job offers to chose from. Most people don't have the options you may have.

Plus, you have families, cost of moving, home ownership, etc, that keeps you in a place even if you might enjoy living somehwere else more.

It takes population densities of greater than 1M/mi^2 to truly feel overcrowded, and even in NYC you only see such densities in localized incredibly high-traffic spots, like Times Square and Herald Square. The vast majority of Manhattan is never so crowded as to feel suffocating.

My parents live in a residential area that looks like your average American suburb - no stores, just houses and cars. But if you walk west of their house for 10 mins, you go to a large boulevard full of restaurants, shops, and people hanging out. It felt like a nice balance, but I doubt there are many jobs in there for the residents, so most do make the highway trip to LA proper.

Autonomous cars are going to give the suburbs a new lease on life. They will make it easier than ever to live in far flung places because you'll be able to work from the car on the way to work. Autonomous cars will require less parking downtown, but I imagine they'll convert the parking to driving lanes for the widely anticipated massive increase in vehicle miles travelled.

You wouldn't know if by the tens of millions of people who live in those densest cities. It seems like an astronomical numbers of people can "bear it" just fine.

I guess to some people but I love NYC and find strolling in central park very unsuffocating. The main problem with NYC is most people do like it and would quite like to move there so the prices are bid stupidly high. Property prices being high because people want to move to a place are generally a sign of successful design.

I didn't think Tokyo felt that dense when I was there but very big to get around - over 100km long and taxis costing something like the price of international flight within europe.