By Jonathan Fildes, BBC News
June 4, 2008
The whereabouts of more than 100,000 mobile phone users have been tracked in an attempt to build a comprehensive picture of human movements.
The study concludes that humans are creatures of habit, mostly visiting the same few spots time and time again.
Most people also move less than 10km on a regular basis, according to the study published in the journal Nature.
The results could be used to help prevent outbreaks of disease or forecast traffic, the scientists said.
“It would be wonderful if every [mobile] carrier could give universities access to their data because it’s so rich,” said Dr Marta Gonzalez of Northeastern University, Boston, US, and one of the authors of the paper.
Dr William Webb, head of research and development at the UK telecoms regulator, Ofcom, agreed that mobile phone data was still underexploited.
“This is just the tip of the iceberg,” he told BBC News.
The new work tracked 100,000 individuals selected randomly from a sample of more than six million phone users in a European country.
Each time a participant made or received a call or text message, the location of the mobile base station relaying the data was recorded.
The researchers said they were “not at liberty” to disclose where the information had been collected and said steps had been taken to guarantee the participants’ anonymity.
The results showed that most people’s movements follow a precise mathematical relationship – known as a power law.
“That was the first surprise,” he told BBC News.
The second surprise, he said, was that the patterns of people’s movements, over short and long distances, were very similar: people tend to return to the same few places over and over again.
“Why is this good news?” he asked. “If I were to build a model of how everyone moves in society and they were not similar then it would require six billion different models – each person would require a different description.”
Now, modellers had a basic rule book to follow, he said.
“This intrinsic similarity between individuals is very exciting and it has practical applications,” said Professor Barabasi.