Will autonomous cars be more economical/efficient as shared urban transit than busses or trains, and by how much? What's some good research on this?

I remember thinking through the potential evolution of autonomous transportation* some 10 years ago, and, barring the protectionist forces winning out and enshrining the "right to drive" in law, like the "right to bear arms", it's pretty clear where the transportation is going.

1. One- or two-person electric commute vehicles dominating city traffic, eventually leading to the whole swaths of urban areas being closed to human drivers, which would be deemed unsafe. Those areas will then expand outwards and merge, eventually spreading into the suburbs, and at some point major highways, first with HOV lanes, then taking over the rest lane-by-lane. Owning a car will become very expensive, and a human-driven car prohibitively so.

2. The huge parking lots will disappear, since uber-like electric commuters will be in use much more often and can be stored efficiently in much smaller spaces during off-peak times.

3. Everything will be routinely recorded, whether outside of the vehicle or inside it, limiting the type of activities one can indulge in while getting to the destination. Vandalism will virtually disappear, as well. Ride sharing will complete strangers will be as safe as walking along them on a busy street somewhere in central London.

4. Once there are no more human drivers, in the autonomous-only areas the vehicles themselves will be able to communicate and coordinate, and soon will be required to do so, forming a driving grid. Any vehicle not complying with the grid inclusion rules will not be allowed in, or forced to stop and get towed outside. Yes, the grid will eventually take control from the single vehicles.

5. Once that happens, the traffic lights will be largely obsolete. There will be pedestrian crossings, with the Walk/Stop signs, but no usual traffic lights, since there will be no human drivers to look at them.

6. The current alternating pattern of driving through the intersection will change: without pedestrian crossings cars will simply zoom in all directions, their movement perfectly choreographed by the grid. With pedestrian crossings there will be breaks for humans to cross on foot in all directions at once. Odds are, many crossings will be replaced with walkways above or below ground.

7. Congestion will be greatly reduced due to coordination. Worst case you'd have to wait to get your ride, as the grid will limit the number of vehicles to keep the system at peak efficiency. Traffic jams will be extremely rare, since most current causes of it will be eliminated, such as broken down cars, accidents, high volume traffic, power outages, road work (the grid will shape the traffic around any roadwork in progress).

8. The city architecture will change to accommodate the new transportation realities: there will be much less road space needed, so some of the wide busy streets will be repurposed for parks, living spaces, etc.

This is as much as I recall offhand, but there is definitely more.

Now, to answer your question, the costs will eventually go down orders of magnitude compared to the existing means of transportation. Which does not mean that price will go down nearly as much, as everything will be heavily taxed, like train and plane tickets now.

Edit: I expect this will happen first in places with high penetration of autonomous vehicles. Places like, say, Oslo. Also in the countries where the government can exert some pressure and ensure compliance and coordination, like, say, in China and maybe Japan. The US will be one of the last ones, and the most expensive ones, as is customary with most technological innovations lately.

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* The language will evolve accordingly:

• "self-driving car" will be a name for DIY driving, the opposite of what it is now.
• self-driving will be reserved for antique car enthusiasts, who would tow their cars to a "driving range" and show off their skills in this ancient activity, sort of like horseback riding is now.

Hey there! I researched a lot of these things recently and made a post [LW · GW] here about it.

Some particularly relevant things to your post: The yet non-existent (at scale) system you describe is Personal Rapid Transit (PRT). The best podcar design is likely a one-seater with a fully-reclined passenger. Fully-reclined minimizes air resistance along with used road volume, but people may prefer partially-reclined for comfort.

One great measure of efficiency is total cost of ownership per mile. Cars have a minimum total cost of ownership per mile 3x ($0.5 vs < $0.2) that of trains, but are admittedly pretty big.

Space is at a premium in cities, and mass transit makes 15-30x more efficient use of it than cars. It's possible PRT can match this with smaller vehicles and tiny headways. Busses go a lot slower than trains, limiting their effectiveness. 75% of bus cost is the driver in the US. They tend to be used more as feeders for trains in many cities.

You can look at other countries for answers to some questions: Paris and Tokyo have pretty cheap housing and amazing train systems and still have commuting.

One cool thing about PRT is the vehicles can be super light, possibly allowing the road itself to be cheaper (especially bridges and raised sections). I think PRT is most promising as a transport system for lower densities since trains seem almost as good in cities. Otoh lower densities come with higher road network and utility cost.

Alon Levy has a blog on everything transit related and is absolutely meticulous. He's not infallible, but a great resource for tons of different metrics.

Strong Towns is a great book on municipal finances and incentive structures.

CLT construction may result in 35-floor buildings as cheap per sq-ft as typical 5-floor wood buildings today.

I'd love to talk sometime.

In the short-medium term (next 30 years, say), change is going to be gradual. It will take a LONG time to overcome all the edge cases of current driver, traveler, and pedestrian expectations. We'll see more ride-share and semi-autonomous, and portions of the ride-share will become autonomous, but not a lot of end-to-end differences.

I haven't seen much study of the demand side of things - what is the actual price/time/convenience elasticity of common travel desires. I know that commute times stay fairly constant - people move further out when roads improve. I don't see why that will change - people will take more distance (and cheaper/roomier housing) over less time/resources for their commute. I do strongly expect that people will simply travel longer and more often as it gets cheaper/easier to do so.

Rail is here to stay, as it combines actual efficiency of resources with the populist demand for central provisioning and subsidies. Busses tick the same boxes (though less convincingly), and probably stay for the same reason.

@makoyass I think you would be interested in The End of Traffic and the Future of Access . I haven't read it, though I have read some of Levinson's other work; it's a bit on the dry-and-wonkish side, but I expect you would prefer that to "rabid conflict-theorist", and it's covering the right sort of ground.