Phone GPS Data Shows Traffic Problems
December 20, 2012

Mobile Phone Data Used To Pinpoint Source Of Traffic Congestion

Peter Suciu for — Your Universe Online

Death and taxes are two things that no one can avoid, but there have been countless efforts made to help drivers avoid congestion and traffic tie-ups. From GPS devices that offer real time traffic updates, to news radio stations that offer traffic updates every 10 minutes, drivers will go to great efforts — and sometimes even great distance — to keep moving and avoid sitting in go-nowhere congestion.

The biggest problem is in many cities, traffic growth has outpaced road capacity and this often results in traffic jams, notably in the morning and evening, or the so-called “rush hour” commutes. While a 2007 study indicated traffic congestion accounts for 4.2 billion hours of added travel time, it also resulted in 2.8 billion gallons of fuel consumption and the accompanying increase in air pollution.

Getting cars off the road through various efforts, including flex time and allowing workers to clock in from home, has been on the rise. Researchers at several leading centers of higher learning have concluded something most drivers have with them could help pinpoint traffic tie-ups.

The problem is this study won´t actually help drivers avoid that traffic, but could rather be a way to help determine how communities might tackle the problem in other ways, such as increasing public transportation and offering more options for flex time and working from home.

The first step is determining what would actually reduce traffic. It isn´t just less cars on the road, but apparently cars from specific neighborhoods at specific times.

Researchers at MIT, Central South University in China, the University of California at Berkley and the Austrian Institute of Technology have released a study that incorporates data from drivers´ mobile phones. Published in the December 20 issue of the journal Scientific Reports, it demonstrates efforts that cancel or even delay the trips by one percent of all drivers across a road network could reduce delays caused by congestion by just three percent.

However, canceling trips by a select one percent of drivers from select neighborhoods could reduce the travel time by all other drivers in a metropolitan area by as much as 18 percent.

“This has an analogy in many other flows in networks,” says lead researcher Marta González, the Gilbert W. Winslow Career Development Assistant Professor in MIT's Department of Civil and Environmental Engineering. “Being able to detect and then release the congestion in the most affected arteries improves the functioning of the entire coronary system.”

The researchers based their findings on three weeks of mobile phone data to obtain information about drivers´ routes and then estimated traffic volume and speed on those routes. The study looked specifically at two major metropolitan areas — Boston and San Francisco — and considered factors including population density, location and capacity of the roads, and determined which neighborhoods were the largest sources of drivers on specific segments.

The researchers further considered which roads those drivers used to connect from home to highways and other major roadways.

The findings suggest reducing a little traffic from key areas would greater solve traffic congestion in big ways.

In Boston, canceling one percent of trips in the Everett, Marlborough, Lawrence, Lowell and Waltham areas could potentially cut commuting time caused by traffic congestion for all other drivers by 18 percent. In the San Francisco area, the study found canceling trips by drivers from Dublin, Hayward, San Jose, San Rafael and parts of San Ramon would result in a 14 percent reduction in travel time for other drivers.

“These percentages are averages based on a one-hour commute with additional minutes caused by congestion,” said MIT postdoc Pu Wang, now a professor at Central South University. “The drivers stuck in the roads with worst congestion would see the greatest percentage of time savings, because the selective strategy can more efficiently decrease the traffic flows in congested roads.”

Whether this will convince those in the aforementioned communities to delay or cancel their respective trips is yet to be seen. When it comes to traffic, most drivers tend to blame everyone else and think the horn was likely invented just for them!