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Self-Driving Cars Will Mean More Sprawl

Driverless cars will have some environmental advantages, but their very efficiency will challenge planners and conservationists

Sprawling suburban areas like Irving, Texas, could become even larger as the number of driverless cars increase. The implications for both wildlife and the environment are widespread and complex.
Image Credit: La Citta Vita via Flickr

By Timothy Hodgetts

Self-driving cars will change how we live, in all sorts of ways. But they won’t just affect us humans — the coming revolution in autonomous transport has significant implications for wildlife as well. Nature conservationists and planners need to think hard about the impact of driverless vehicles, most notably in terms of renewed urban sprawl.

In some ways, wider developments in automotive technology bode well for the environment. Electric cars will increasingly replace the internal combustion engine, and that should, in theory, reduce carbon emissions and health-afflicting air pollution.

Through minimizing traffic jams, driverless cars may also reduce overall energy use. Unlike human drivers, computers can avoid the “concertina” effect of needless acceleration and braking that exacerbates congestion, and won’t be tempted to “rubberneck” when passing an accident. And, as autonomous vehicles aren’t restricted by human reaction times, it may make sense to increase speed limits for them on major inter-city routes.

So driverless cars promise a future of faster journey times with much reduced environmental impacts. They may even mean less wildlife roadkill. But it’s the very efficiency of driverless cars that poses a challenge for planners and conservationists. The threat is an unchecked increase in low-density urbanization.

Driving into the countryside

Autonomous vehicles promise a future in which passengers are free to use their time productively (working, for example). And driverless vehicles can park themselves (or be part of a shared pool) which saves yet more time in the morning rush. Coupled with faster journey times, the incentives to live further out of town will increase significantly.

There are both push and pull factors at work here: sky-high residential prices in most cities push people away from urban centers while healthy environments and green living pull people towards the hinterlands. The limiting factor in suburban spread is often travel time, either by public or private means. Driverless cars fundamentally alter the equation.

Existing planning policies are based on our current transport systems. Green-belts, for example, are designed to reduce urban sprawl by restricting development within a buffer zone around an urban area. However, the reduced transport times offered by driverless cars make it easier to live outside the belt while still working inside. So these loops of green are in danger of becoming a thin layer in a sandwich of ever-spreading suburbanization.

This is, of course, a familiar challenge since the rise of the automotive age in the 1940s. However, the solutions designed by planners have been calibrated for a human-driving automotive system — not for the supercharged future of driverless transport.

Other examples of planning protection for wildlife include nature reserves, national parks and (in the U.K.) “areas of outstanding natural beauty.” Such areas have either strict controls on development, or do not permit it at all. However, they are nice places to live in or nearby. The coming revolution in automotive journey times and the ability to work behind the (computer-driven) wheel will make living in such areas increasingly compatible with a commute to the nearest city.

Sick of sprawl

Natural habitats being lost entirely or splintered into ever-smaller fragments have long been understood as some of the primary causes of species extinctions across the world. Renewed urban sprawl threatens to increase the magnitude of both habitat loss and fragmentation. These threats are well known among conservationists, but there are differences of opinion on how best to respond.

For example, eco-modernists advocate a strategy of “land-sparing,” whereby human activities are concentrated into urban areas and vast tracts of land are set aside for nature. There are many cultural and ethical problems inherent in herding humans into cities, but the near-term planning issues posed by autonomous vehicles will exacerbate the challenge given they will boost demand to live in “unspared” lands.

Alternatively, some conservationists advocate “land-sharing,” in which human communities redesign the way we farm and live so as to co-exist with wildlife, cheek-by-jowl. Autonomous vehicles pose significant challenges for either approach, by supercharging the fragmentary effect of road systems.

Whichever approach is taken, we’ll need to redesign existing systems and policies to take account of the increased range that driverless transport facilitates. This may involve new zoning laws to protect wider areas of countryside than at present. It certainly requires further development of green infrastructure, habitat corridors and “greenways.”

It might also involve engineering solutions, especially given the fact that autonomous vehicles should be much more amenable to being driven underground. It is possible to imagine a future in which the famous bear bridges of Banff are tiny precursors to a vast program in which rural highways are covered with forests of green. Retrofitting roads into tunnels won’t be cheap, but it becomes easier when human drivers are taken out of the equation. Software drivers are less bothered by artificial light and more efficient at mitigating the congestion impact during construction.

Much conservation policy is based on planning for the world we live in now. Strategic conservation planning needs instead to take account of likely futures. And in a future of driverless cars, that is likely to result in the mega-cities of the 20th century becoming the mega-sprawls of the 21st. Unless, of course, planners and conservationists rise to this new challenge.

Timothy Hodgetts is a research fellow at the University of Oxford. This post originally appeared at The Conversation.


  1. vensonata | | #1

    Off grid exodus via autonomous car.
    There could be radical changes in real estate prices. Two factors together can cause that: autonomous cars and off grid made easy and affordable. The land prices off grid in rural areas are so cheap compared to urban on grid that many may be lured away. Suburban prices will drop, then urban land will drop. There will be "sprawl" but it doesn't have to be intrinsically bad. The price of PV and batteries by 2020 and the ease of "smart" tech will push an exodus to the countryside, just as 100 years ago the opposite happened.

  2. jkstew | | #2

    I don't think so
    Those autonomous cars have to come from someplace, i.e. the city, before they get to your house to pick you up, so the service will probably only be available and be practical to city dwellers. For those in rural areas, they'll have to own cars and it may or may not be practical to own an autonomous one. In either case, autonomous cars don't promote suburban living. Just the opposite. The cars on the road will downsize. Currently, people own the truck or SUV for that 1% of the time they need the truck or SUV and then they drive 6000 lbs of steel to the supermarket to get a bag of groceries the other 99% of the time. Autonomous vehicles will dramatically reduce that form of waste. If you need a truck, you send for a truck. If you need a car, you send for a car.

  3. JC72 | | #3

    Liability concerns make autonomous vehicles a long way off.
    The insurance industry hasn't yet figured out how to insure autonomous vehicles. The big question is who is responsible in the event of an accident. Is it the operator of the vehicle or the owner of the software?

    In any case until the software can safely navigate a vehicle in inclement weather and take evasive maneuvers I don't think we have anything to worry about.

  4. GBA Editor
    Martin Holladay | | #4

    Response to John Clark
    Self-driving car enthusiasts tend to live in places like Palo Alto, California -- places with paved roads and almost no snow.

    Self-driving cars have not yet been shown to work in places like Vermont, where the majority of roads are unpaved (where do you put the white lines when the road surface is gravel?) and where wind-driven snow (and snow-covered roads) are a fact of life for 6 months out of 12.

  5. user-2511396 | | #5

    The efficiencies of driver-less cars (accordion effect, rubber-necking, etc.) will only happen if everyone has a driver-less car. Won't happen unless by mandate and the American government takes people's cars away. Good luck.

  6. AntonioO | | #6

    Echo to comment 5
    I agree with Brendan Meyer. I don't expect autonomous vehicles to be significantly more efficient than human driven vehicles if we all share the same roads. But, will there be autonomous vehicle lanes initially?

    On another note, can someone explain why an electric vehicle powered from a roughly 35% efficient (when all power production, transmission and distribution losses are combined) grid source will be so much better for the environment than what we have presently?

  7. GBA Editor
    Martin Holladay | | #7

    Response to Antonio Oliver
    The short answer is that in areas of the country where most of the electricity comes from coal-burning power plants, electric cars produce more pollution than gasoline-powered cars. However, in areas of the country where renewable energy makes up a higher proportion of the electricity generation mix, electric cars produce less pollution than gasoline-powered cars.

    The good news is that on average in the U.S., electric vehicles reduce pollution compared to gasoline-powered vehicles.

    The other piece of good news is that the grid is getting cleaner every year. Coal-fired power plants are being phased out, and an increasing percentage of our nation's electricity is coming from wind and solar sources. This means that over the expected lifetime of an electric car, the environmental benefit of driving an electric car (compared to driving a gasoline-powered car) will improve every year.

    Here are links to two articles with in-depth information on this issue:

    Are Electric Vehicles Better for the Environment than Gas-Powered Ones?

    Gasoline vs Electric—Who Wins on Lifetime Global Warming Emissions?

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