Smartphone App Helps You Avoid Red Lights and Save Gas

It seems inevitable that if you're driving down a road with a dozen traffic lights, you'll run into a dozen red ones. Stop-and-go driving tends to exacerbate road rage, particularly if you're in a hurry, but it's also a drain on gas. Wouldn't it be neat if there was a way to time it so you could cruise through intersections without ever stopping (and without having to punch the gas when you see a yellow light)? Like almost everything else, there's an app for that.

A team of scientists and researchers at the Massachusetts Institute of Technology (MIT) built an app called SignalGuru that's supposed to predict when a traffic signal is about to change, and what speed you should drive when approaching the intersection.

"The stop-and-go pattern that traffic signals create increases fuel consumption significantly," said Emmanouil Koukoumidis, the scientist who came up with the app. "We wondered how we could help drivers cruise through signal light intersections without stopping, and how much we could save on gas and improve the flow of vehicles."

SignalGuru works its gas-saving mojo by using the camera on a driver's dash-mounted smartphone. When it detects a traffic signal in the distance, it taps into its database to determine when the signal is going to turn from green to red (or vice versa), and then tells the driver what speed he/she should be going to avoid getting stuck at a red light.

There are obvious safety concerns with this system, but Koukoumidis says the app always recommends a speed within the speed limit. He also says that the driver should check for himself whether the light has turned green or not. Safety concerns aside, Koukoumidis says his team of researchers noted a 20 percent decrease in fuel consumption using a prototype in the Cambridge area.