What do you do when you see yellow?

What do you do when you see yellow? »Play Video
Driver uncertainty about how to react when a light turns yellow at an intersection is often the cause of accidents. (Photo courtesy of Oregon State University)

CORVALLIS, Ore. -- When you're driving along and you see an upcoming yellow light, drivers have a decision to make: they can either slow down to stop at the intersection, or speed up to drive straight through it.

The area of the road where this choice is made is known as the "dilemma zone," and Oregon State University researchers said they're studying this area to cut down on the number of crashes on roadways.

"What we hope to do is understand the factors that contribute to a driver slowing down and stopping or accelerating and continuing through an intersection while they make that decision," said David Hurwitz, Assistant Professor of Civil Engineering at OSU. "And with that knowledge we can improve the way we design signalized intersection."

Hurwitz and student researchers are using a virtual reality lab, complete with a real car and screens that make it look like you're driving on a real road. Using that model, researchers are trying to find out where drivers hit the dangerous "dilemma zone."

"Some will be given the yellow when they're real close," OSU graduate student Derek Moore explained. "Then the next time they'll get the yellow when they're further back, and you try to see where that area where the decision is the hardest is."

"It's tough sometimes, after driving around in here for a while, to go outside in the real world," said Moore.

Hurwitz said the first step is to identify where the dilemma zone is for drivers -- two, three, or five seconds away from the intersection, perhaps -- then figure out how to keep people out of it.

"We don't want people to be located in the dilemma zone when the light turns yellow," said Hurwitz. "So we want to ultimately use technology to prevent that from occurring."

Technology and design, Hurwitz said, "where we're constantly tracking the speed and position on the approach to the signalized intersection. And with that information, we can assure in many situations we don't get caught in a dilemma zone."