Automated vehicles: more driving, energy wasted, & congestion

Preface. There’s no need to actually worry about how automated vehicles will be used and their potential congestion, energy use, and whether there are enough rare earth minerals to make them possible, because they simply can never be fully automated, as explained in this post, with articles from Science, Scientific American, and the New York Times: “Why self-driving cars may not be in your future“.

There are two articles summarized below.

Alice Friedemann  author of “When Trucks Stop Running: Energy and the Future of Transportation”, 2015, Springer and “Crunch! Whole Grain Artisan Chips and Crackers”. Podcasts: Practical Prepping, KunstlerCast 253, KunstlerCast278, Peak Prosperity , XX2 report ]


Taiebat, M., et al. 2019. Forecasting the Impact of Connected and Automated Vehicles on Energy Use: A Microeconomic Study of Induced Travel and Energy Rebound. Applied Energy247: 297

The benefits of self-driving cars will likely induce vehicle owners to drive more, and those extra miles could partially or completely offset the potential energy-saving benefits that automation may provide, according to a new University of Michigan study.

Greater fuel efficiency induces some people to travel extra miles, and those added miles can partially offset fuel savings. It’s a behavioral change known as the rebound effect. In addition, the ability to use in-vehicle time productively in a self-driving car — people can work, sleep, watch a movie, read a book — will likely induce even more travel.

Taken together, those two sources of added mileage could partially or completely offset the energy savings provided by autonomous vehicles. In fact, the added miles could even result in a net increase in energy consumption, a phenomenon known as backfire.

Traditionally, time spent driving has been viewed as a cost to the driver. But the ability to pursue other activities in an autonomous vehicle is expected to lower this “perceived travel time cost” considerably, which will likely spur additional travel.

The U-M researchers estimated that the induced travel resulting from a 38% reduction in perceived travel time cost would completely eliminate the fuel savings associated with self-driving cars.

“Backfire — a net rise in energy consumption — is a distinct possibility.

Mervis, J. December 15, 2017. Not so fast. We can’t even agree on what autonomous, much less how they will affect our lives. Science.

Joan Walker, a transportation engineer at UC Berkeley, designed a clever experiment. Using an automated vehicle (AV) is like having your own chauffeur. So she gave 13 car owners in the San Francisco Bay area the use of a chauffeur-driven car for up to 60 hours over 1 week, and then tracked their travel habits.  There were 4 millennials, 4 families, and 5 retirees.

The driver was free.  The study looked at how they drove their own cars for a week, and how that changed when they had a driver.

They could send the car on ghost trips (errands), such as picking up their children from school, and they didn’t have to worry about driving or parking.

The results suggest that a world with AVs will have more traffic:

  1. the 13 subjects logged 76% more miles
  2. 22% were ghost errand trips
  3. There was a 94% increase in the number of trips over 20 miles and an 80% increase after 6 PM, with retirees increasing the most.
  4. During the chauffeur week, there was no biking, mass transit, or use of ride services like Uber and Lyft.

Three-fourths of the supposedly car-shunning millennials clocked more miles. In contrast to conventional wisdom that older people would be slower to embrace the new technology, Walker says, “The retirees were really excited about AVs. They see their declining mobility and they are like, ‘I want this to be available now.’”

Due to the small sample size she will repeat this experiment on a larger scale next summer.

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8 Responses to Automated vehicles: more driving, energy wasted, & congestion

  1. Joe Clarkson says:

    An experiment like this needs to continue for more than a week. Just the novelty of having a chauffeur driven car would promote maximizing use of the driver. Let the experiment continue for a few months to see what the equilibrium usage rate would be.

    • Forrest says:

      Joe is correct that the novelty factor distorts the conclusion of Joan’s experiment. Another important factor is the “free” issue. If users have to pay the cost for each trip they will reduce frivolous use.

    • energyskeptic says:

      This experiment will be repeated, as I wrote at the end of this post: Due to the small sample size she will repeat this experiment on a larger scale next summer.

      But it doesn’t matter: we will simply never have fully automated vehicles for the reasons explained in this post: “Why self-driving cars may not be in your future” with articles from Science, Scientific American, and the New York Times.

      • energyskeptic says:

        First of all, autonomous vehicles are clearly not ready for prime-time — imagine the destruction and death a truck could cause. From the March 19, 2018 Guardian:
        “Self-driving Uber kills Arizona woman in first fatal crash involving pedestrian Tempe police said car was in autonomous mode at the time of the crash and that the vehicle hit a woman who later died at a hospital”

        Secondly, the Uber trucks “won’t be fully driverless—-they’ll still have human safety drivers behind the wheel.
        “Truck drivers possess the critical skills that self-driving trucks may never match — like backing into a tight dock, navigating a busy industrial yard, or moving axles on a trailer,” Uber wrote in a November blog post.

        Third, look at a map, the trucks are going between Topock and Sanders Arizona. We were just there – no traffic, no people, no stop signs.

        And I bet trucks only go in perfect weather for reasons explained in “Why self-driving cars may not be in your future”

  2. NJF says:

    Techno jeebus strikes again. Even most millennials are yawning at these silicon valley journal articles now. They’ve begun to have as much follow-through as Marvel comics.

    Road transportation is broken, but not because it isn’t automated. It’s because people weren’t satisfied with simply replacing horses (the gold standard for millennia who could only sustain a trot of appx. 8 mph long-term) and instead insist on 70-75 mph speed limits that chew up the roads (especially the semi trucks going that speed) and lead to unmitigated slaughter when they crash at those speeds.

    Some people act like reducing the speed limit to 55 is an assault on their freedom. Jesus, is going twice the speed of a racehorse at a dead-out sprint really that tyrannical of a suggestion? Especially to dramatically reduce vehicle weight and material use, cost, road repair and construction costs, and lost lives?

    Plus, fast speed limits are all psychological manipulation. People would rather go 50 mph half the time and 0 mph the other half than go 25 all the way, so arterials get built, idiotic Radburn pattern suburbia gets put up, everything becomes 5 miles away, and then gas gets too pricey and the whole thing is useless.

    • david higham says:

      Perhaps the future will see the ‘End of speed’. I was thinking about horses too. They aren’t automated vehicles,but they have many times been used as something better: self homing transport.
      The horse often got used to a routine,and could be relied on to
      bring the cart or buggy home with little or no guidance. Horses
      used on milk or ice deliveries would generally know the routine
      as well,and know where they were expected to start and stop.
      Self replicating as well. No mining or manufacturing required.
      Not much use in today’s cities. Smaller everything is required:
      smaller settlements,smaller populations,slower speed.

      • energyskeptic says:

        My great grandfather was a doctor in Oklahoma. After a night call far out in the country, he’d crawl into the buggy and the horse would take him home. He sure hated cars when they came along, that quickly ended the “automatic” horse travel.

  3. NJF says:

    A barrel of oil does do that though… It doesn’t take an entire barrel of crude to lift up another barrel of crude. “Gushers” like Spindletop accessed oil that didn’t even need to be pumped; the weight of the earth pushed it up…