Shared autonomous vehicles have uncertain effects

December 15, 2017 by Benjamin D. Leibowicz, University of Texas at Austin
Credit: University of Texas at Austin

The next revolution in transportation is expected to be shared autonomous vehicles, with personal cars yielding to driverless cars summoned on demand. For instance, Uber passengers in San Francisco, Pittsburgh and Phoenix can already hail driverless cars, and Bay Area Lyft riders will soon have the same opportunity.

This transportation revolution may seem like a positive development, but without careful planning, it could end up doing more harm than good.

It's true that shared autonomous vehicles have the potential to make road faster, easier and cleaner. Yet, there are reasons to suspect that they could actually lead to heavier traffic, dirtier air and more greenhouse gas emissions. Transportation accounts for 27 percent of U.S. greenhouse gas emissions, so the environmental stakes are high. Now is the time to ensure that these shared autonomous vehicles contribute to a future.

The benefits of these types of cars are numerous, and companies probably will adopt electric cars faster than individual owners will. Shared vehicles accumulate higher mileage, which amplifies the fuel cost savings from using electricity instead of gasoline.

As wind and solar generate growing shares of electricity, electrification of shared vehicle fleets would reduce significantly. Additionally, electric vehicles could facilitate wind and solar uptake by charging at times of abundant renewable electricity supply and low electricity demand, or by providing vehicle-to-grid battery storage.

Autonomous vehicles also achieve superior fuel economy by accelerating and braking more efficiently than human drivers can, and can use sensors and communicate with nearby vehicles to travel at high speeds even in dense traffic. Each minute not spent in traffic or waiting at a red light means avoided energy consumption and emissions.

Carpooling services that allow passengers with similar routes to travel in the same vehicle have the potential to increase average occupancy and satisfy demand using fewer vehicle miles. But drivers have been lukewarm about UberPool.

On the contrary, shared autonomous vehicles might make people travel more. The value of time is a major cost of driving. Autonomous vehicle travel is effectively less costly than driving because driverless car passengers can work, eat, or do other activities while en route. According to the "rebound effect," when the cost of an activity declines, demand for it increases.

It would therefore not be surprising if autonomous vehicles cause people to make longer and more numerous trips. The long-run travel increase could be severe if passengers tolerate longer commutes and opt to live in distant locales with cheaper housing. Additional miles require more energy use and associated emissions.

After an autonomous vehicle drops off a , the fleet operator might reposition it to a location where new passengers arise more often, or where there is a dearth of available cars. These miles driven without passengers are termed "deadheading," and a recent study that simulated shared autonomous operation concluded that it could add 10 percent more travel miles.

This all means that lawmakers in states and cities across the country should anticipate widespread adoption of these vehicles. They should enact policies to ensure that they contribute to—rather than impede— reduction efforts.

First, governments should regulate transportation to set ambitious emission standards for shared fleets. They are favorable markets for , and a stricter form of the Zero Emission Vehicle program implemented by California and nine other states could be applied to these vehicles.

Second, public transportation agencies should rethink their services so that shared autonomous vehicles complement public transportation rather than compete with it. In particular, these vehicles help solve the "last mile" problem and make not owning a car more feasible. Dallas Area Rapid Transit collaborates with Uber to provide door-to-door trips.

Third, land-use policies could counteract the rebound effect of shared autonomous vehicles on travel demand by inducing compact and mixed-use development. These urban forms reduce trip lengths and encourage walking and biking. Austin is currently redeveloping its land-use code with an eye toward more compact and connected communities.

The climate change impacts of shared autonomous vehicles are highly uncertain. But, by enacting appropriate policies now during their formative phase, we can make them an integral component of a sustainable transportation future.

Explore further: GM says next-gen electric cars will cost less, go farther

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Eikka
not rated yet Dec 15, 2017
Shared vehicles accumulate higher mileage, which amplifies the fuel cost savings from using electricity instead of gasoline.

electric vehicles could facilitate wind and solar uptake by charging at times of abundant renewable electricity supply and low electricity demand, or by providing vehicle-to-grid battery storage.


These are contradicting goals, because one is assuming the car spends more time on the road, and the other assumes it spends more time stationary and plugged in waiting for the opportunity to serve or be served by the grid. Both cannot be achieved at the same time.

Secondly, the shared cars have a similiar cost structure to rental cars, which recoup part of the cost of the car by selling them second hand after a few years of service. As the number of car owners decreases, the value of second hand cars drops like a rock, and the cost to rent goes up in turn, making the system uncompetitive.
Eikka
not rated yet Dec 15, 2017
The second point is because a rental/sharing service cannot operate an old beat-up car for liability reasons, and for the risk of breakdowns. They have to adhere to legal standards and compete with other providers, which means they have to either sell the vehicles after a number of years, or scrap them, much sooner than a private owner would.

If they can't sell the vehicles because nobody wants to own a car, they have to shift the loss into their prices, which means fewer people can afford their service.

Furthermore, the share/rental service needs to add its own overhead to the price, and then some for profit, both of which don't apply to the individual car owner, which too makes it more expensive for the customers than simply driving your own car. It all balances such that the great working class masses will never be driving rental/shared cars for the sheer cost of it.

MR166
not rated yet Dec 15, 2017
Electric cars should become more reliable than gas powered ones. Thus they should last more years. Also sensors should be able to predict most failures. As cars communicate with each other there should be a lot less heavy braking and acceleration. Lastly highways should be able to handle more cars per hour under automatic control. A vehicle that is operated to it's full potential should be cheaper to run than one that sits idle much, if not most, of the time and loses much of it's value due to aging not use.
snoosebaum
not rated yet Dec 15, 2017
one youtuber who might know, suggested the whole robot car thing is to keep faces in front of advertisers longer
Eikka
not rated yet Dec 16, 2017
Electric cars should become more reliable than gas powered ones. Thus they should last more years.


Electric cars have batteries, which have much shorter shelf-lifes than the usual service life of a car, and there's no incentive for manufacturers to actually make you a car that lasts longer when they want you to buy a new one every five years.

A vehicle that is operated to it's full potential should be cheaper to run than one that sits idle much


That depends on how you define potential. One pays for availability as well as use, so a car sitting on your driveway that you own can be worth more to you than a taxi cab "driving to its full potential".

And again, the rental/shared car cannot be driven to its full potential, because it has to be taken out of service when it starts to show obvious signs of wear and tear. Meanwhile, a private owner can very well drive their own car ignoring a couple rust spots.
MR166
not rated yet Dec 16, 2017
Your argument the there will be no resale market for used self driving taxies does not make sense because people will always need transport. Thus there will be a market for the used vehicle. If there is no market for them that can only mean that the entire used car market has crashed because of the popularity of these taxis. If it can be worked out with reasonable insurance rates due to increased safety, I can see people commuting to work in their SDC ( self driving car ) and then having it become a city taxi cab while they are at work. The battery problem should be solved by new technology by the time that all of the other problems are worked out. There could be 2 or 3 tiers of service at decreasing prices as these cars age. If I could purchase autonomous transportation at a discount due to a little rust I personally would accept the tradeoff.

The biggest problem will be the electronics and programming of these new SDCs. A whole new set of laws will be needed.
MR166
not rated yet Dec 16, 2017
I could see a whole new set of business models developing around these SDCs. Unmanned car washes to keep them clean and perhaps even some sort of robot interior vacuum service.
MR166
not rated yet Dec 16, 2017
I could see using them for courier services. You get a text when your package arrives. People will be sending them to the grocery store for a quart of milk and a dozen eggs or "to go" restaurant meals.

Labor, insurance and gasoline are by far the biggest costs in the taxi industry. I feel that all of these could be significantly lowered by SDCs. Even traffic congestion could be managed by having whole sections of a city communicate with these vehicles.

Pedestrians would be a major problem for the flow of traffic. Once pedestrians realize that these cars will always stop for them they will walk into traffic at will. Right now vehicles and pedestrians play a little game of chicken and are constantly negotiating the right of way. I really doubt that a company would risk programing a SDC to be aggressive enough.
Eikka
not rated yet Dec 17, 2017
Your argument the there will be no resale market for used self driving taxies does not make sense because people will always need transport.


It was an argument against the proposition that shared cars would supercede car ownership. Of course it doesn't make sense, because the situation is impossible. That's the point.

As the number of shared vehicles increases and private ownership drops, the price of second-hand vehicles drops due to a lack of demand, and therefore the cost of first-owner vehicles increases because of the drop in their residual value (2nd hand market price).

Therefore, the cost of riding in a shared vehicle increases, while the cost of obtaining your own vehicle decreses, buffering the market and preventing the self-driving shared vehicles from ever taking over.

Their own popularity will be their downfall.
Eikka
not rated yet Dec 17, 2017
If I could purchase autonomous transportation at a discount due to a little rust I personally would accept the tradeoff.


Ah, but you aren't allowed to, due to health and safety regulations - which the other competing rental/share companies would have lobbied into law to hobble their competition. The premium providers won't want to lose their profits to cheap competitors or private car owners renting their own cars to the public, so very quickly you will see laws and regulations saying things like, you have to be a licensed company to share your vehicles, or you can't share a vehicle more than 8 years old etc. etc.

That's another issue with the common ownership schemes. You lose control.
MR166
not rated yet Dec 17, 2017
I know that many laws will have to change in order to make sharing practical. The age problem is not serious in that these cars will be communicating with networks and have many sensors that will predict many mechanical problems. Since labor costs far outweigh the cost of the car the resale value of a 8 year old taxi is not a significant obstacle. BTW as far a the law goes, look how UBER managed to operate in markets that everyone thought it was impossible to enter like the NYC taxi market.
MR166
not rated yet Dec 18, 2017
I could see how car sharing could raise the standard of living for most people. Say the average car is in actual use 2 hours during the day. If one could change that to 12 hours per day then the cost per hour of use would fall by a factor of 6 excluding increased insurance and depreciation costs. Also with an autonomous car one could be performing useful work during that time. If your car is out on a call and you need it a neighbors autonomous car could pick you up and provide the transportation. The concept is very similar to a vacation time share.

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