[ghaff]

There seems to be an implicit assumption that autonomous driving would somehow make the cost of effectively renting cars by the mile (and have them come to your door) almost too cheap to meter. Whereas, especially for transportation options that involve multiple people in a vehicle, the cost of a driver isn't really all that much relative to the overall cost of operating a vehicle.

For any imagined scenario involving autonomous vehicles ushering in new modes of sharing, renting, etc., a useful question to ask is: "Why don't we have this today?" And, if the answer is anything other than "$10/hour for a human driver makes it too costly," then you should probably reconsider.

[zamfi]

> Whereas, especially for transportation options that involve multiple people in a vehicle, the cost of a driver isn't really all that much relative to the overall cost of operating a vehicle.

Do you have a source on this? It’s my understanding that most mass transit systems in the US spend a huge amount on operator compensation. BART, the one I’m most familiar with, spends $500m of its $691m operating budget on salary and benefits [0] despite the fact that BART trains already drive themselves!

[0]: https://www.bart.gov/sites/default/files/docs/FY18_Budget_Su...

[vonmoltke]

First off, you cannot ignore the $876mm capital portion of the budget; that money needs to come from somewhere.

Second, that $500mm covers every employee of BART. The administrators, maintenance personnel, police, and other non-operator functions do not go away. Without knowing what portion of that line item goes to operators one cannot make a judgement on how much cheaper the system would be without them.

[zamfi]

Of course you're right; my comment was mostly tongue-in-cheek. Actual train operator salaries probably cost BART about $50m annually, not $500m. In both the cases of BART and private cars, the money to pay for tracks or roads comes from taxpayers. The trains themselves are now 40+ years old, and are finally being replaced at a cost of ~$300m this year. Grandparent post specifically talked about operating costs though.

All that said, trains are basically the most efficient mode of transport from a (number of drivers) / (number of passengers) perspective.

But speaking seriously for a moment:

- Lyft charges riders about $2/mile in the Bay Area [0] before fees.

- The IRS lets you depreciate your vehicle at a rate of $0.545/mile.

- A reasonably efficient car burns ~40 mpg on freeway, at $3.50/gallon that's ~$0.09/mile.

So, of the $2/mile the riders pay, about 1/3 of that is costs associated with purchasing and operating the vehicle (according to IRS estimates) and fuel.

If we eliminate the rest via autonomous driving, and taxis became 65% cheaper, I suspect many people would make much more use of them.

[0]: https://www.lyft.com/pricing/SFO

[perl4ever]

Utilization rates are 50-58% for Uber or Lyft. When you take it into account that a taxi is not en route 100% of the time, and add the cost (interest, depreciation) of a much more expensive vehicle, I think your 65% savings go up in smoke.

[zamfi]

Sorry, I'm not smart enough for this comment to stick with me. Could you walk me through how 50% utilization means the savings go up in smoke?

The most compelling thing I can pull from your comment is "autonomous cars will be 3x as expensive as regular cars (at least), so you won't save anything". That may be short-term true, but is almost certainly long-term false.

A 50% utilization compared with 100% utilization makes almost no difference in vehicle cost structure -- if anything, it actually increases the labor fraction of taxi cost.

If you're driving your car 50% of the time, then wear and milage is the dominant depreciation factor (rather than age). But a human sitting around doing nothing but waiting for that 50% of the time doubles the labor (time) cost of the service, suggesting an even greater savings from eliminating the human driver.

What am I missing?

[perl4ever]

I was assuming humans and self-driving cars both get revenue from riders, but don't get paid in between. And I'm interpreting utilization as the percentage of the time that riders are paying.

[mcguire]

How much of the Labor & Wages go to drivers rather than maintenance, security, etc.? The latter are needed even if you don't have drivers.

I couldn't find a breakdown in the paper.

[godelski]

For renting cars there is a big advantage. You may notice that different drop offs have different fees associated. This is because people tend to collect around certain areas. This creates the need for company drivers to redistribute the cars. Being able to do that dynamically and automatically has a huge advantage. It also allows you to make the rental locations more sparse and efficiently packed.

So yes, it does lessen the cost of renting cars. But it doesn't make it anywhere near too cheap to meter.