Everyone has experienced it at some time in their night-driving life: the jerk with the ridiculously bright headlights that makes it impossible to see the road ahead. It's more than a mere annoyance, it's a genuine road hazard, and as vehicles have grown taller and lights brighter, the problem is worsening.

But Rensselaer Polytechnic University's Lighting Research Center (LRC) thinks it has the solution: a method dubbed 'Prime Beam' that works together with a series of sensors to maximize visibility for the driver while minimizing interference with oncoming traffic. It does this by removing on the angular region of the headlight beam that creates glare.

The LRC says that the dangers of headlight glare are serious, and worsen as drivers age. This is due to the longer times required for older persons' eyes to adjust back to the dark after experiencing the glare of the headlights. Precise figures on how much the system will improve safety are wanting, however.

“It’s difficult to directly link glare to crash risk because there are very few accident records attributing glare as the cause of the crash," says John Bullough, Ph.D., head of the Lighting Research Center’s Transportation Lighting Program. "However, since glare reduces visibility, it is logical to use reduced visibility as a surrogate factor for crash risk, which we did. We also looked at drivers' behaviors such as head movements and speed variability as safety surrogates, which seem to occur more frequently when crash risk is higher. In our studies, these different surrogate measures all consistently indicated that glare increases crash risk.”

Current headlights, even though quite bright, do not provide sufficient visibility to safely travel faster than 30-40mph on low-beam settings. That's why improving the ability to use high beam lights without impairing oncoming traffic could prove a double boon to safety.