I'm essentially parroting the (settled and not at all controversial) consensus view of the urban design profession so there's no real end of citation.

Though there are few clear cut real world examples to point to because land use is one of the most highly politicized things and it is rarely exposed to real market forces.

It's a great thing to have arguments about because whenever you can point some examples, people will always nitpick at why it's not real (eg. Tokyo is affordable and dense thanks to low regulation and the market, but people will point at the relatively poor Japanese economy etc).

But from basic geometric principles it makes sense that automobile oriented infrastructure is ultimately unsustainable and more expensive because of the constraints of the real world.

Ultimately the issue one runs into is that a car is a box several feet wide by several feet long (6.7x17.4) for an F150. That's a lot of space both parked and on the road. So if everyone buys one (and largely drives around themselves) it's clear that one quickly fills up the size of the road. The cost of expanding roads is very expensive, disruptive, and occasionally impossible. And then it doesn't even really work in remarkably improving traffic because due to Induced Demand, it reprices driving cheaper, which encourages more people to drive, which refills the road again. Everyone's time is being wasted sitting in these large boxes that cost tens of thousands of dollars.

So the core problem is that cars are enormously space inefficient. The system simply doesn't scale and eventually reaches break down.

You simply have to give up and can't grow the city any further. So you have to push people out to other cities.

But if we think of moving people instead of cars, there's a lot more space efficient opportunities since people are very small.

So you look at things like a bicycle, whose costs are relatively near nil, a protected bike lane that is also effectively near nil (put some jersey barriers on an existing road) and you can move that same person for much less. Obviously the problem is that they can't go very far but a combination of different modes for different uses and you have a system that can actually scale.

Build compact mixed use neighbourhoods that one can walk and bike to for local needs, buses for inter neighbourhood, and trains for intra and inter city long distance travel.

Only with this approach can you can continue to scale a city and continue to have a large city that is functional.

Nothing I'm saying is actually scientifically controversial. I'm literally citing facts from urbanist textbooks. It's just that the way I'm telling them is unsettling for the people who have never questioned the social-engineered "consensus".

E.g. density doesn't decrease housing prices: https://www.strongtowns.org/journal/2023/4/26/upzoning-might...

The CO2 footprint question is a tricky one. The vehicle _itself_ is not the main source of pollution. Even if you compare the vehicles, the answer is not straightforward: https://ourworldindata.org/travel-carbon-footprint The main source of pollution for transit are _drivers_. E.g. each bus needs around 3 drivers to function, resulting in driver-to-passenger ratio of just around 1:7.

So when computing true CO2 footprint, you need to look at a counter-factual scenario where bus drivers are doing something else. But this becomes extremely tricky extremely fast, as you can move into fantasyland where bus drivers are building CO2 scrubbers instead of driving CO2-emitting vehicles. Or where drivers are working on chopping forests for agricultural lands, resulting in huge CO2 increases.

The next best option is to look at different regions and compare them. E.g. Houston, TX with EVs would have smaller CO2 emissions than the current NYC, with climate corrections.