A central entry point to all your city's data

Where do citizens and developers go for information in your city? Perhaps for public transport timetables they have to visit the websites of the local bus and tram companies, for information about bin collections to a local council site, for crime data to the local police website ... and so on.

CityData is a platform that brings geo-coded information from local councils, departments and agencies together in one place. Different agencies can upload or link data from existing systems, using an intuitive web front end or via a powerful API, into grouped spaces on the platform where they can retain their distinctive branding. They can review data before it goes live. Citizens and users can search for data they need or get notifications of new data in areas that concern them. It uses non-proprietary, open-source software, tried and tested on large existing projects such as datagm.org.uk, a data platform for the Greater Manchester area.

Data can be linked on external sites, or held as structured data on the CityData server, in which case a suite of visualisations and maps are available to users as well as an API to query the data. By making local data from many sources discoverable and searchable, CityData encourages app developers to build services using multiple data streams - for example, combining geospatial transport and house price data to make suggestions to a user who needs to find a place to live.

This is a project of CKAN (ckan.org) by the Open Knowledge Foundation.

We live in a world awash with a bewildering amount of data. This data presents huge opportunities, but also huge challenges. The danger is of drowning in data without ever finding the data we need - or even knowing that it exists. The data held by local governments and agencies could be used in an endless variety of ways to improve people's lives. In order to unlock its potential, however, three things must happen: the data must be made open, it must be accessible, and it must be turned into information.

Unless the data is free to use, we can't even get started in generating value. The next most important phase is to make the data findable; open data becomes valuable when people know where to go to get it, and when the costs of finding the data you need are removed. To take the final step and turn data into information, it must be possible to search it, create visualisations, and combine it in new and productive ways.

The challenge of unlocking the data revolution in cities is that data exists in many different places, agencies, formats, and degrees of openness. The triple challenge that CityData helps to meet is of taking this sprawling mass of data and making it open and accessible, and enabling information to be extracted from it.

CityData is based on CKAN, a free, open-source Data Management System written and maintained by the Open Knowledge Foundation. It can be easily integrated with existing web content using an innovative 'side-by-side' integration method that we have successfully pioneered. CKAN powers major data portals such as data.gov.uk in the UK and the Europe-wide pulicdata.eu, as well as existing city-wide portals like datagm.org.uk and www.hri.fi.

CityData makes it easy to publish, share and find data, with a powerful database for cataloguing and storing datasets, and an intuitive web front-end and API that enables it to be added seamlessly to existing workflows. It can be extended with social features such as comments and Twitter integration, usage stats via Google Analytics, and integrated data-storage with built-in visualisation tools and data API.

A CityData instance can be set up for a local council, and can immediately be used as a central repository of data from the council's various departments. Often if data-sharing is ad-hoc this will already create a more efficient source of council data than is currently available, but its value will grow by getting buy-in from other local agencies (and perhaps councils) and encouraging them to work together, to open up their own data (if it is not already open) and register it on the CityData platform. Once there, CityData adds activity streams and workflow elements to encourage the refining, linking and re-use of data.

CityData would minimise information assymetries, remove friction hindering local development and provide a central access to a variety of public goods. It would save resources and increase productivity and boost local innovation potential.

Several studies have estimated the economic value of open data at several tens of billions of Euros yearly in the EU alone. New products and companies are re-using open data. The Danish husetsweb.dk helps you find ways to improve the energy efficiency of your home, including financial planning and finding builders who can do the work. It is based on re-using catastral information, information about government subsidies as well as the local trade register. Google Translate uses the enormous volume of EU documents, which appear in all European languages, to train the translating algorithms, thus improving its quality of service.

Again and again, such examples have two features in common: they involve re-use of open data, and they use data from different sources. By making local data from a wide variety of sources accessible and discoverable in one place, CityData removes obstacles to local innovators building apps that contribute to the local economy.

Information is power. Making data easier to find empowers citizens to make better decisions for themselves. Better information about events, film showings, swimming pool locations and opening times, transport timetables, current traffic conditions, rubbish collections, etc, can allow people to get the most out of of local services, make faster journeys, and make better use of their leisure time.

By encouraging and fertilising app development around the data available through the CityData platform, local councils can further increase the value of the data to citizens tenfold. A woman in Denmark built findtoilet.dk with all Danish public toilets so people she knew with bladder problems now trust themselves to go out more again. A service in the Netherlands, vervuilingsalarm.nl, sends you a warning if the air quality in your vicinity tomorrow is expected to reach a threshold set by you. In New York you can easily find out where you can walk your dog, as well as find other people who use those parks - a direct example of strengthening community and making cities smaller.

Many of the efficiencies that CityData encourages and enables naturally tend towards reducing climate impact, especially through reducing the number or length of car journeys - for example, enabling more efficient use of public transport through timetable and real-time data; enabling users to avoid making car journeys when congestion is already high; enabling users to find nearby services and providers, reducing the length of journeys; and enabling users to find cycle facilities such as cycle lanes and parking, promoting cycle use.

It can also help reduce impact in a much more direct way, if participating agencies are required or encouraged to open up data about their own climate impact, for example their energy use. The concentration of this data and its accumulation over time will make it possible to create and monitor policies for a gradual reduction of energy use and other indicators, or to put pressure on the agencies via campaigns, reward systems, inter-agency comparisons, etc.

Finally, climate data from a network of CityData platforms can be aggregated onto a larger regional, national or transnational data platform (as publicdata.eu aggregates data from EU platforms), making possible the collection of far more granular data than is currently feasible and informing the development of more targeted and efficient policies, climate taxes and interventions.

It is increasingly recognised that more transparency in government both creates confidence in the democratic process and enables and encourages greater participation. Transparency requires open data where people can find it. CityData helps you organise and publish your Open Data, and helps your citizens find it.

Publishing details of council processes and spending opens up local government for all to see. Not only does this help create confidence that resources are being spent wisely; better informed citizens can participate more fully. CityData allows users to 'follow' particular datasets and organisations, enabling local journalists, third-sector organisations, activists, and engaged citizens to get regular updates of data in their area of interest.