You have just finished breakfast when your phone pings, confirming that your driverless car has arrived. Five minutes later you are on the way to work, travelling in a convoy of robo-vehicles. Even at 70 miles per hour, your car stays only a few feet behind the one in front; it will react to an emergency many times faster than you could. You pay little attention to the other vehicles in any case, since you are reading. But at one point you glance over at the lane reserved for old-fashioned cars driven by humans. As usual, it is hardly moving. Mugginses, you think.
In the past decade self-driving cars have gone from an engineer’s fantasy to a reliable technology. Google’s autonomous bubble cars are putting in 10,000-15,000 miles a week on public roads. Next year 100 self-driving Volvos will start trundling around Gothenburg in Sweden. Road regulations and legal liability will take a while to sort out, and the cars must still learn to cope with snowflakes. But it is a good bet that a lot of self-driving cars will be on the roads by the middle of this century.
Almost immediately, some people’s lives will improve. The old will find it far easier to get around, points out Josef Hargrave of ARUP, an engineering firm. So will teenagers and disabled people. All drivers will be safer, as will pedestrians. But at that point the future becomes fuzzy. Whereas car-watchers mostly agree that robo-vehicles are coming, they don’t agree on how people will use them, or how they will change the landscape. What kind of city will flash by during your commute in the future? Will it be packed with vehicles, or pedestrianised and green? And will the home you leave in the morning be a detached house in the suburbs or a high-rise flat in the city centre?
One answer to those questions begins with a bird’s eye view. Look at a city like San Jose, or even Rome, on Google Earth and it is astonishing how much land is occupied by car parks. Many of the cars that are moving are just looking for a place to rest – one study in Brooklyn found that 45% of drivers were cruising for a parking space. Driverless cars should make this unnecessary. If you own one, you could pilot it to the office, then send it home and order it to pick you up at the end of the day. If you use a car service, you could summon the nearest empty vehicle using your phone, just like requesting an Uber.
The land that cars now squat upon might be put to all sorts of lovely uses. The city of San Francisco already has a “pavement to parks” programme, which encourages people to turn roadside parking spaces into cafés or tiny outdoor art galleries. That is just a start. Shopping malls and sport stadiums, which now resemble islands surrounded by oceanic car parks, could be enclosed with greenery. Plants would clean the air and keep the heat down: the air temperature in a park is typically 2°C lower than in the surrounding streets. Other car parks could be turned into offices or flats. Designers might well revive an old architectural feature, known as the porte-cochère. These covered porticos, seen on grand old houses, protected passengers in horse-drawn coaches from the rain; in future people could alight from driverless cars under similar structures.
That is one view of the future. It is held by people who believe that cities – especially American ones – took a wrong turn, almost a century ago, towards cars and sprawl, and that they can be straightened out again by technology. It also assumes that self-driving cars will mostly displace driven cars, not other kinds of transport. In this view, people who now commute by car will carry on doing so, but without crashing into pedestrians or hogging lots of space in city centres; everyone else will walk, cycle or take public transport. Perhaps, because city centres become so lovely and dense, some people who previously drove will now have the opportunity to live in the centre of town and therefore will no longer require a car.
But there is another possibility. It derives from an observation made in the 1970s by Yacov Zahavi, an Israeli traffic scientist. Zahavi noticed that Americans spent about the same amount of time travelling each day, regardless of which city they lived in or how they got to work – a little over an hour on average. Given speedier transport, they did not use the time saved to work longer hours in the office or relax at home. Instead they travelled farther. Americans still spend about an hour a day travelling on average; so do Britons.
Self-driving cars will be able to follow each other so closely and precisely that roads dedicated to them could carry up to five times more traffic, according to America’s transport-department. On such roads, traffic lights will be unnecessary. Cars will weave round each other without stopping, hugely increasing traffic flow. As cars speed up, two things will happen. First, drivers who now live ten miles from work will eye homes 20 miles away. Secondly, some of the people who now take trains or buses will hop into driverless cars. After all, they will be cheaper: you will need to pay for neither a driver nor for parking. The upshot will be epic sprawl.
These scenarios sound like opposites, but they might not be. Driverless cars could lead to nicer, denser city centres even as they make it easier to live miles away from them. Downtowns and distant villages could both become more appealing. But something must lose out, and perhaps that something is the old-fashioned suburb.
In a world of trains and traffic jams, suburbs look like an excellent trade-off between space, convenience and cost; in a world of zippy self-driving vehicles, they seem much less so. If you own a home in a cul-de-sac or on a street named after a tree, wait until you see a bubble car, then sell.