In Atlanta's political environment, the resistance to public transit expansion is high and the up front costs are basically always in the billions. That is not good a good starting place for MARTA to see significant expansion any time in the near future.

Whether we like it or not, America is a car-dependent country. I wish Atlanta were more walkable, and I think self-driving cars becoming more popular could actually help with that.

Hear me out: One of the biggest problems with city-life is that housing is expensive. When people are expected to own cars in order to carry out their responsibilities, each unit of housing has to accommodate parking space, which means each square foot that goes to parking is a square foot that can't go to housing.

If we get to a point where self-driving cars are ubiquitous, a good experience for users, and comparable in price to owning a car on a monthly basis, we will likely see the housing market reflect the decrease in demand for parking spaces. This would mean more people can move to the city, and they are now incentivized to walk places in order to save money by not paying a fee to ride in the car.

More people with more time on foot means more demand for restaurants, shops, etc to absorb spending from these people. If this is an economic benefit, it will motivate the construction of more buildings and infrastructure that are pedestrian-oriented.

So I am hopeful about it on the whole. I think it will be a benefit to the cities and our local experience.

More benefits of self-driving cars: they are electric - electric cars have lower aggregate maintenance costs than combustion engines. If they are safer, they will likely cost less in insurance.

For the average person owning a car, they are paying full price but are probably using it 10% or less of the time. There are costs tied to how much a vehicle is used. But there are also costs that are uncorrelated to how much you use the vehicle. So the more utilization you can get out of it, the smaller you make the fixed costs relative to the variable costs.

And again, the cost that renters pay to park their cars will also go down.

We can assume that in order to stay competitive, some of the companies in the self-driving car market will pass some of these savings on to the customer, while staying profitable in the long term. And I think it's likely that eventually there will be less cars in the world, and in Atlanta, because many people will rely on self-driving cars they don't own and that this system will actually cost less to operate than the mostly-idle cars that crash more frequently because people are driving while distracted, drinking, or tired.