How much commuting can you tolerate? A new study by MIT researchers shows that across countries, people assess their commutes by the time it takes them to complete the trip, generally independent of the distance they have to travel — as long as they have a variety of commuting options to chose from.

The study, which compares commuting practices in five locations on four continents, also demonstrates the methodological validity of using mobile phone data to create an accurate empirical picture of commuting.

“Every country has had its own different way of doing things and collecting data,” says Carlo Ratti, an associate professor of the practice in MIT’s Department of Urban Studies and Planning, director of MIT’s Senseable City Lab, and a co-author of the new study. “Here we have standard data which allows us, for the first time, to evaluate mobility across countries.”

Commuting research has often been conducted via surveys, making it difficult to develop cross-country comparisons. But by using anonymized phone data, the MIT researchers found some fundamentally similar patterns in different locations.

“It really reveals that commuting patterns around the globe are constant,” says Stanislav Sobolevsky, a researcher at the Senseable City Laboratory and a co-author of the paper, published in the journal PLoS ONE. The paper’s co-authors are Ratti, Sobolevsky, Kevin Kung, and Kael Greco, all of the Senseable City Laboratory.

“There was an element of surprise in how well the data showed this,” says Kung, the corresponding author on the paper.

From Massachusetts to Africa

The researchers studied three metropolitan areas where a diversity of transport options let commuters keep travel times steady.

In Portugal, people could tolerate about 70 minutes of commuting in the morning, a figure that held fairly constant for commutes ranging anywhere from about 5 kilometers to more than 40 kilometers. About 28 percent of commuting trips around the country’s largest city, Lisbon, occurred on public transport — suggesting that commuters seem willing to budget the same amount of time whether they walk, drive, or take buses or trains.