Video: Drive safe with Android app

Back-seat driver now available in software (Image: Carlos S. Pereyra/SuperStock)

You don’t have to be rich to get the latest and best in advanced in-car gadgetry. A smartphone app gives any old rust bucket two key safety features you would normally expect to see only in luxury vehicles: a lane-departure warning and driver-fatigue alerts.

In cars like Toyota’s high-end Lexus range, lane-departure systems use cameras and radar to warn drivers when they drift out of a traffic lane. Cameras trained on the driver’s eyes can sense the kind of blinking that indicates you are drowsy, telling you to take a break.


Andrew Campbell and colleagues at Dartmouth College in New Hampshire have packed similar capabilities into an Android app called CarSafe. With a Google Galaxy Nexus phone mounted on the windscreen, the front camera points at the driver, tracking head pose, gaze direction and blink rate. If the driver seems drowsy, a coffee cup appears on the screen and the phone bleeps.

The back-facing camera is trained on the road and the app checks you are at a safe distance from the car in front and also checks you are not weaving outside the white lines of the traffic lane.

The technological challenge is not trivial, says Campbell, as existing cellphones can’t access both cameras at once. So the team has written code that continually switches between the two cameras – but that means they can only analyse scenes at a rate of eight frames per second, reducing the app’s ability to assess safety when the car is travelling at speed.

“But the next generation of phones will allow software to access both cameras simultaneously, removing that bottle neck,” predicts Campbell. “And with advent of quad core and 16 core phones in the future I would expect 20 to 30 fps [frames per second] on each camera.”

Track tests in a Subaru Outback, Ford Focus, a Hyundai sedan and a Toyota pickup truck have been encouraging – and the team are now moving on to “realistic” road tests. If it works, Campbell thinks such safety-centric apps “will be common in two or three years”. The research was presented at the UbiComp conference in Pittsburgh, Pennsylvania, earlier this month.

Kevin Clinton, head of road safety at the UK’s Royal Society for the Prevention of Accidents in Birmingham, notes that apps which monitor your driving style for insurance purposes are already emerging – measuring how harshly you accelerate, brake and corner for instance. He says the lane departure warning element of CarSafe could be incorporated in such apps – though he doubts the usefulness of its tiredness monitoring capability. “We think it’s a little bit late by the time an app tells you you’re tired,” he says.