JUANA, who came to America from Guatemala, used to take the bus to and from cleaning jobs. It wore on her. Walking to the bus stop after a long day at work was exhausting, especially when it rained, as it occasionally does in Los Angeles. Now Juana drives everywhere, even to her local supermarket, a few blocks away. She had two aspirations: to learn English and to get a car. She has accomplished both.

Although Los Angeles has organised itself around the car since the second world war, it has tried harder than many other American cities to change this. Since 1990 voters have approved three tax rises to pay for public transport. A railway and rapid-bus network has been built quickly—by rich-world standards, if not Chinese ones. Public-transport users, however, are dwindling. In the past five years the number of trips taken in metropolitan Los Angeles has dropped by 19%.

The City of Angels is leading a broad decline. The American Public Transportation Association’s figures show that the number of journeys in the country as a whole has fallen in each of the past three years. In 2016-17 every kind of mass public transport became less busy: buses, subways, commuter trains and trams. New Yorkers took 2.8% fewer weekday trips on public transport and 4.2% fewer weekend trips in the 12 months to April 2018, compared with the previous year. In Chicago and Washington, DC, the decline in public-transport trips has been even steeper.

Public transport is holding up better in other rich countries, but not by much. In Toronto, adult trips have fallen every year since 2014 (the city made public transport free for young children, so their numbers are up). In London, bus journeys are down by 5% since the 2014-15 fiscal year. The London Underground has remained more popular, although in the year to March 2018 the number of Tube journeys fell by 19m, or 1.4%. That was despite annual population growth in London of about 1% and a 3.3% rise in employment in the past year. The Paris Metro carried only as many passengers in 2017 as it did in 2012. In Berlin, public transport journeys are growing about half as quickly as employment.

There are exceptions. More people are taking public transport in Sydney and Tokyo. And some transport agencies can point to specific reasons for their emptying buses and trains. London and Paris have suffered terrorist attacks. New York’s subway is creaking—a consequence of prolonged underinvestment in repairs. Elsewhere, bad weather or roadworks are said to deter people from taking buses. But demand for mass public transport has weakened in so many rich-world cities at the same time that one-off explanations seem inadequate. Not long ago annual passenger growth of more than 2% was normal, and transport-watchers mused that the private car was on its uppers. The recent decline, which is bad enough on a year-to-year basis, looks even worse when set next to transport agencies’ forecasts. In New York, for example, bus trips in the first four months of this year were 7.6% lower than the transport agency expected. Something seems to be driving people off the trains and buses. But what? One explanation, which is convincing in some cities, is that public transport has deteriorated. Look at Madrid, says Richard Anderson, a transport analyst at Imperial College London. Public-transport trips fell there beginning in 2008, as you would expect in a recession-hit country where unemployment was rising. In response to the downturn, the city cut services. People noticed, and stayed away. Between 2007 and 2013 the Madrid Metro lost 19% of its customers. Service levels, perceptions and demand have all improved since then, but the Metro remains quieter than it used to be before the financial crisis. Elsewhere, though, customers are vanishing even though public transport is as good as it was, or better. Perhaps public transport has come to seem relatively dismal because people have acquired better options. Uber, Lyft and other “ride-hailing” car services are probably luring people away from trains and buses, just as they are demolishing the taxi trade. In San Francisco public transport accounts for 16% of all weekday trips, ride-hailing for 9%. People mostly seem to use Uber and Lyft to get to places well-served by mass transport (see map). One study of the city by five Californian academics asked ride-hailing customers how they would have made their most recent trip if the service did not exist. One-third replied that they would have taken public transport. In a study of Boston, 42% said the same thing.

Self-driving taxis are likely to steal even more riders in future, because they will be so cheap. They can threaten public transport even before they appear on the roads. Last month voters in Nashville overwhelmingly rejected a plan to build several tram and rapid-bus lines. Opponents of the plan had argued that autonomous cars and buses would soon be a cheaper and better way of transporting people.

Two wheels good

Meanwhile, other technologies nibble at buses and trains. Many cities have tried to encourage cycling by creating bike lanes and allowing app-based bike-rental outfits (and, in some, scooter-rental outfits) to set up on pavements (see article). In Berlin, the network of cycle paths has grown from 856km to 1,433km since 2002. App-based rental schemes—the largest of which is run by Lidl, a discount supermarket—have grown from 2,000 to 16,000 bikes in two years. Cycling, although still uncommon, is proportionally the fastest-growing commuting mode in America.

The consequences of the rise in two-wheeled travel are not entirely clear. Cycling could boost public transport by helping people get to stations; or it could undermine public transport by providing a cheap alternative to buses and trains. Susan Shaheen, a researcher at the University of California, Berkeley, suggests that both of these can happen at once. In Washington, DC, bicycle-sharing seems to bring more people to public transport in the suburbs but draw them away in the city centre.

Another possibility is that city-dwellers are simply travelling less. Footfall in London’s shops was 1.5% lower in May than a year earlier—a slump that the British Retail Consortium blames on the growth of online shopping and weak consumer confidence. It means fewer travellers, especially to West End stations such as Oxford Circus. “When the retail sector suffers, we suffer as well,” says Shashi Verma, the chief technology officer at Transport for London. In several cities, including Paris and San Francisco, weekday trips have held up better than weekend trips, hinting that people are dropping unnecessary outings.

Working habits are changing, too. Gallup, a pollster, found in 2016 that 43% of American workers spend at least some of their time working remotely, up from 39% in 2012. Remote working also intensified—ie, telecommuters spent more of their time telecommuting. In Britain, the numbers working exclusively at home grew from 2.9m in 1998 to 4.2m in 2014, according to official statistics.

“Most people who I know work at least one day a week at home,” says Sandra Jones, an expert on London property at Dataloft, a consultancy. She points to two other changes that may have kept people off buses and trains. Even when workers do get out of the house, many travel to flexible “co-working” offices, which might be close to home. The second change is a rash of office development around railway stations. The Office Group, a fast-growing outfit, actually rents offices inside stations. The company says these are popular among commuters from outside London, who can take a train to work and no longer have to transfer to a Tube train or a bus.

In almost every city in the rich world, the fiercest competition for public transport comes not from Uber, cycling or the appeal of working from one’s back garden. Rather, it comes from driving. In America 76% of commuters drive to work alone, and the share has risen fractionally in the past decade. The final explanation for the emptying buses and trains is that the lonely car journey has become more appealing.

It is certainly cheaper. The oil price began to fall in the summer of 2014. It has since rebounded, but not to its elevated levels of five years ago. Meanwhile, car engines have become more frugal. Cheaper oil greatly cuts the cost of driving around America, where fuel is only lightly taxed. Even in Britain, data from the RAC Foundation, a research group, suggest that driving-cost inflation (which includes fuel as well as insurance and so forth) has been lower than bus- or train-ticket inflation over the past ten years.

Despite a loudly trumpeted urban revival, America’s suburbs and more distant “exurbs” are growing faster than its central cities. Many of these places have poor public transport and plenty of room for cars, thanks to rules that oblige developers to provide a minimum number of parking spaces. Some European cities are sprawling, too. Berlin, long a cheap city (and an artists’ haven as a result) is turning costly. Knight Frank, an estate agent, says that home prices in the city have risen by 21% in the past year. Those who leave Berlin in search of cheaper housing find an impoverished railway network, with only one train an hour on some lines. So they drive.

Four wheels better

In southern California, public transport is heavily used by poor immigrants, particularly immigrants from Mexico and Central America. But research by Michael Manville and others at the University of California, Los Angeles, finds that this group are rushing onto the roads behind their own steering-wheels. Between 2000 and 2015 the proportion of Mexican immigrant households without a car fell from 16% to 5%. Meanwhile, the immigrant population of Los Angeles and its environs is becoming a little less Hispanic and a little more Asian. “The countries that were most likely to send us transit riders are sending us a smaller proportion of immigrants,” says Mr Manville.

Along with other working-class Americans, Mexican immigrants find it easier to buy their own cars these days because loans have become so much cheaper and easier to obtain. Since 2015 some of them have also benefited from a Californian law that allows illegal immigrants to have driving licences. Perhaps more of them are arriving in America knowing how to drive, too. Car ownership is rising quickly in Mexico, as it is in other countries, such as the Philippines, that send lots of immigrants to America.

However, even in the cities where public transport is faring worst, it seems unlikely to disappear. People will keep using it when it is convenient, when they are feeling pinched, or when it is raining. But the days when commuters and shoppers followed regular tracks around cities, like migrating birds, appear to be over. Tony Travers, an urbanist at the London School of Economics (and a convert from the Tube to cycling) calls it: “a fragmentation of the world as we knew it”.