The road shoulder beam which improves nighttime visibility in the rain

Yuichi Shibata and Hiroyuki Serizawa (Koito Manufacturing Co., Ltd.)

Background

Visual information take 90% of total amount of information for nighttime driving task, and the most of them obtained from illumination of own headlamps. But the driver is losing those visual information in adverse weather. Because retroreflection coefficient of the road surface is declines as the road get wet. Additional glare sources should be taken into account such as forward reflection of oncoming headlamps and street lights at the road surface. These glares also reduce visibility.

Improving nighttime visibility is desired especially in those situations. We have strong demand in Japan where we have much rain.

We derived new concept of beam patter for adverse weather from practical experiment and build low cost system to make the lamp affordable.