Mobile phone data from tens of thousands of people are creating computer-generated images that show the peaks and valleys of human activity throughout a city.

US researchers at the Massachusetts Institute of Technology (MIT) are using anonymous and voluntary data to offer traffic planners a new way to track congested areas and give emergency workers real-time data that could radically transform the way they work.

"Instead of broadcasting general messages, it would be possible to send people the best instructions on how to behave based on their location and movement patterns," says project leader Dr Carlo Ratti, an architect and engineer who heads the SENSEable City Laboratory at MIT.

Ratti's team is conducting its research in Graz, Austria, in partnership with a mobile phone company.

Starting in September, the company's mobile phone network began automatically sending anonymous information about the density of mobile phone calls made and the origin and destination of calls.

The team also used a function similar to text messaging to 'ping' voluntary participants at regular intervals about their precise locations.

Back at MIT's Mobile Landscape project, Ratti's team analysed the data and converted it into electronic maps that could be overlaid with each other or on top of a street map.

Potentially, such maps can be referred to in real time and used by people who want to be in the action, or avoid it.

"A tourist may go to the most crowded area to see what's going on and others may go to a quiet area to enjoy the historical place. Taxi drivers want to come to a crowded area, but avoid such areas after dropping off a customer," says Professor Toru Ishida, head of the department of social informatics at Kyoto University in Japan.

Unanswered questions

In addition to offering real-time data for the benefit of city planning, Ratti believes that the availability of such dynamic information will raise many questions.

How should location information be managed? By whom? What will be rules and conditions of using it?

To open these questions up to answers, the project will be on display at the M-City exhibition in Graz from 1 October to 8 January 2006.

Visitors will have a chance to participate in the real-time map by sending a text message to a special phone number.