Except that the market isn't sorting it out. Do you think government regulations mandating free and abundant parking come from the market?

It's amazing how many people in America think our car-dominant culture is just the result of market forces.

The truth is that land use for transportation is zero sum enough to make market forces impossible to use in the way we expect for most consumer services. If you want choices, the best option is to support multi-modal transportation, which in most US cities means reallocating resources away from cars (who currently have almost all the resources) and towards walking, biking, and transit.

I was claiming that markets should sort it out, not that they are sorting them out

What makes you think that markets would be any good at sorting things out? The externalities of car usage (such as air and noise pollution, traffic accident victims) are ignored by the free market. Furthermore, the 'traffic' market has a tendency towards monopolies: more people using cars means less people using public transportation making the latter less profitable, resulting in worse service, leading to even less people using it...

Free markets need very specific conditions to lead to the optimal solution. I don't think the transportation market fits the requirements.

Air and noise pollution are probably reasonable examples, but I don't think traffic accident victims are.

Why do you think traffic accident victims are not reasonable examples of negative externalities of cars? As I mentioned elsewhere in this thread: 35.000 motor vehicle deaths in 2015 in the US alone [1]. According to the US department of transportation [2], the total economic cost of motor vehicle crashes in 2010 is estimated to have been $242.0 billion. I don't see how you can reasonably ignore that in any discussion about transportation and cars.

[1] https://en.wikipedia.org/wiki/List_of_motor_vehicle_deaths_i...

[2] https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/...

I don't think they're an example of something that markets would be unlikely to handle. I suspect any system of private roads would at the bare minimum require liability insurance.

Interesting perspective. Now I understand what you're saying.

I think it would be dubious that private roads would require liability insurance. At present, liability insurance is only widespread because of regulation (i.e. a non-market mechanism). I do not see the economic case for the owner of the road to require liability insurance of its users.

Insurance wouldn't cover the full cost either. According to [2], total car insurance losses were $117.5 billion in 2011, compared to the $242.0 billion in economic losses cited in my previous post.

[1] https://www.ibisworld.com/industry/automobile-insurance.html

[2] http://www.iii.org/fact-statistic/auto-insurance

And how exactly should the markets sort out something that involves a natural monopoly? Do you think markets should also sort out use of different spectrum frequencies?

Didn't the public (who make up the market) vote for those in govt. office, who then make these decisions?

A luxury is a good you consume more of as you get wealthier. For example, environmental regulation is a luxury good, which is why many people don't see the need for limiting pollution if it gets in the way of accumulating wealth (and why richer nations tend to have more pollution laws).

The first sentence is well formed but the example makes no sense at all to me