The Timeline for Self-Driving Cars and Shared Mobility May Take Longer Than We Think
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The Timeline for Self-Driving Cars and Shared Mobility May Take Longer Than We Think

Examining the long-term future of automated vehicles, electric vehicles and shared mobility.

The coming decades promise some potentially large changes in personal mobility, including widespread use of electric vehicles, the introduction of fully autonomous vehicles (AVs), and the possible replacement of individually owned vehicles with “Mobility as a Service” (MaaS). So I’m grateful to Ed Regan for his five-part Public Works Financing series on disruptive change. Ed was kind enough to provide me several of the many sources he is researching for his series. While there is a range of outlooks about future mobility change, one seemed to be particularly aggressive and somewhat unrealistic about the pace and magnitude of disruptive policy change. That is a report from RethinkX called, “Rethinking Transportation 2020-2030” (May 2017). Among its claims are the following:

  • Fully autonomous vehicles (presumably SAE Level 5) will achieve regulatory approval and be marketed in 2020.
  • By 2030, those AVs will provide 95% of all U.S. passenger miles of travel.
  • Those miles will all be in shared vehicles (Mobility as a Service), rather than in personally owned AVs.
  • These AVs will all be electric and will last 500,000 to 700,000 miles on their initial battery pack.

Not one of these assumptions is shared by those actively working on AVs, whether in technology companies or in traditional auto companies. My Reason colleague Baruch Feigenbaum is just back from the seventh annual Transportation Research Board AV conference, in San Francisco—generally considered among the most important of the many conferences on this subject. Here are a few points from his notes on the conference:

“Companies are adopting a much more cautious timetable relating to AVs. Most seem to agree that Level 3 AVs are not safe, because the human is likely to tune out when he needs to [quickly] take control of the car. Automakers and tech companies are increasingly certain that they can get to Level 4 AVs relatively soon, but since these vehicles will be able to drive only in some locations [and weather conditions], humans will still need to retain their driving skills…Level 5 vehicles are looking increasingly untenable before at least 2035 and maybe 2050.”

As for electric autonomous vehicles (eAVs), there is no necessary connection between electric propulsion and autonomy. And since the current generation of electric vehicles costs close to double what a comparable-size internal-combustion vehicle costs, and since autonomy itself requires lots of costly sensors and software, the affordability of eAVs, at least over the next decade or two, is questionable, contrary to ThinkX’s rosy scenario in which they are cheaper than conventional cars by 2020.

Then there is ReThinkX’s assumption that eAVs will operate for 500,000 to 700,000 miles with their original battery pack. A reality check on this comes from the websites of current electric vehicle producers. The Toyota Prius battery pack has a warranty of 10 years or 150,000 miles. The Tesla Model 3 battery is warranted for 8 years or 100,000 miles.

On the subject of Mobility as a Service, McKinsey offers a somewhat more-cautious report, “How Shared Mobility Will Change the Automotive Industry” (April 2017). It concludes that “shared mobility will only partially replace car ownership,” for a number of reasons. First, many surveys find that a majority of US residents say they would prefer to own their vehicle, rather than relying on shared mobility. Second, McKinsey notes that shared mobility is unattractive for many trips that people take, such as running errands, multi-stop shopping trips, and the potential of “uncomfortable dynamics among people who are basically strangers.” Despite its virtues, the McKinsey report’s statistics on current uses of “shared mobility” conflate two different categories: car-pooling (which is shared mobility) and ride-hailing (via Uber or Lyft) which is mostly individual trips displacing taxi trips.

The 2018 TRB AV conference also discussed Mobility as a Service. Baruch reports that “The projections on [the extent of] shared vehicle use are also declining. Actual modeling, which takes today’s use of carpooling into consideration, is showing that outside of dense cities, sharing vehicles may not work for most people.” In my book, Rethinking America’s Highways, I cite a 2018 cover story from Thinking Highways (August 2017), in which Bern Grush and Blair Schlecter (who favor an AV future dominated by MaaS) cast doubt on scenarios like those of RethinkX. They describe nine categories of trips for which people are far more likely to prefer their own vehicle to one that’s shared with strangers and does not provide direct door-to-door mobility for their trip. These may include people with children, people with pets, those who are trip-chaining on the way to or from work, those requiring storage for tools and equipment, and those concerned about communicable disease. My best guess is that if and when MaaS is offered widely in driverless vehicles, it will find most of its market in dense urban cores (like Manhattan, downtown Boston and Chicago, and the District of Columbia). The large majority of Americans live and work in suburbs, exurbs, and rural America, where MaaS is unlikely to be workable.

I think all three of these trends—AVs, electric vehicles, and shared mobility—have a future in America. But large-scale adoption of any of them is more like decades away, not mere years. It is not premature to think about the long-term implications of these trends for things like urban land uses and the amount and types of highway capacity we will need. But it’s far too early to start tearing down parking structures or deciding not to expand highway capacity. On the latter point, KPMG in 2015 estimated that, other things being equal, Level 5 AVs would increase vehicle miles traveled (VMT) by empowering children, elderly people, and disabled people to have personal mobility. Because of this, they projected that total US VMT in 2050 would increase to 5 trillion from today’s 3 trillion. There will likely be some offsetting factors, but after attending the annual TRB AV conference for the past six years, Baruch reports the emerging consensus is that AVs will lead to more, rather than less VMT.

And that is bullish for 21st-century highways.

A version of this column first appeared in Public Works Financing.