WAITING for a bus on a drizzly winter morning is miserable. But for London commuters Citymapper, an app, makes it a little more bearable. Users enter their destination into a search box and a range of different ways to get there pop up, along with real-time information about when a bus will arrive or when the next Tube will depart. The app is an example of how data are changing the way people view and use cities. Local governments are gradually starting to catch up.

Nearly all big British cities have started to open up access to their data. On October 23rd the second version of the London Datastore, a huge trove of information on everything from crime statistics to delays on the Tube, was launched. In April Leeds City council opened an online “Data Mill” which contains raw data on such things as footfall in the city centre, the number of allotment sites or visits to libraries. Manchester also releases chunks of data on how the city region operates.

Mostly these websites act as tools for developers and academics to play around with. Since the first Datastore was launched in 2010, around 200 apps, such as Citymapper, have sprung up. Other initiatives have followed. “Whereabouts”, which also launched on October 23rd, is an interactive map by the Future Cities Catapult, a non-profit group, and the Greater London Authority (GLA). It uses 235 data sets, some 150 of them from the Datastore, from the age and occupation of London residents to the number of pubs or types of restaurants in an area. In doing so it suggests a different picture of London neighbourhoods based on eight different categories (see map, and its website: whereaboutslondon.org).

The result shows what many Londoners already instinctively know, but in a way which is visually striking: that, despite being divided into 33 boroughs, parts of the city can mirror one another. Young people cluster in rented digs in east or south London. Older people are spread much farther out. Many boroughs, in turn, have to cater for several different social types. Kensington and Chelsea, one of the wealthiest, is nearly exclusively uniform. But in Willesden, in north-west London, for example, older residents live cheek-by-jowl with young professionals and poorer people in social housing. Such data may question the way a city is divided up, suggests Dan Hill, an executive director at the Future Cities Catapult. It could also have implications for the way council services are provided, and whether schools or hospitals could be built across borough boundaries.

It makes sense that cities release reams of data for developers to fiddle with. Kit Malthouse, London’s deputy mayor for business, says the city does not know what to do with 60-70% of the data it collects. And academic research can be used by the providers of public services. Oliver O’Brien, a researcher at University College London, has mapped how many people enter and exit Tube stations, and how this has changed over time. His research has been used by Transport for London, the authority governing the city’s roads and underground, which released the data in the first place, but did not have such a nifty tool to look at them. Such data should be useful for staffing plans.

But along with releasing more data, the city should also be analysing them itself, argues Andrew Collinge, the assistant director of intelligence at the GLA, and using them to make decisions about the city. So far this has proved tricky. Part of the problem is that, in contrast to New York or Chicago, where large city-wide data stores are available, City Hall does not control every service in London. Each borough looks after local things such as waste collection. But not every borough will collect the same information, while private contractors may also run services. And there’s still a “culture battle” in order to persuade people to release more data, adds Mr Collinge.

This may be starting to change. Mr Collinge is trying to establish a “borough data partnership” to pool data more effectively, such as that on adult social care. This would make it easier to trace the impact of reforms to certain services on the city. And in five sites in London the Future Cities Catapult has installed sensors to monitor air pollution, in order to advise both councils and companies on how to deal with it.

It helps that the bosses of cities are also becoming keener on using data. An infrastructure plan for London launched in July by Boris Johnson, the city’s ambitious mayor, mentions data 25 times and devotes a section to how they can become a “key element of planning and operating cities”. Manchester is also good at commissioning reports full of statistics to make its case. As cities start to demand more power from Britain’s highly centralised government, their leaders will need to learn how to use data more effectively.