"The thing is when you have some catastrophic event you want to have some way to react. This information is going to help you react in the best way that you can," he said. "I don't think it's going to happen in the short-term. ... Data is going to be the crucial ingredient to make that happen. It would be like trying to predict the weather without weather stations. You need the data."
In addition to offering a window into how people travel, the study, the first of its kind done by the university, raised several privacy issues.
First, the cell phone users were being tracked without their knowledge. In the United States, that type of monitoring without a customer's permission is illegal, an FCC spokesman told The Associated Press.
Hidalgo, however, defends the use of the data, comparing it to political exit polling or data collected on the development of certain diseases, such as HIV cases or tuberculosis.
"We did have [privacy] concerns, and obviously, we went through great lengths to make sure the data was anonymized and secure," Hidalgo said.
"At a global level there is still a need for the information. That doesn't [mean we] need to sacrifice individual privacy. … We're scientists and we're trying to understand things. We're trying to improve the way that the world functions."
Dan Childs contributed to this report.