The Impact of Color Correlated Temperature (CCT) on Automotive Headlights Performance and Driver Perception

Automotive lighting has been evolved from simple incandescent lamps to advanced LED based AFS and ADB functions. These lighting play crucial role in road traffic enhancing better visibility and safety to driver as well as other road users. Today’s Automotive Headlights use different light sources viz., Halogen, HID (Xenon), LED, and Laser each emitting light at different correlated color temperatures (CCT), measured in Kelvin (K). Color temperature not only influences visibility but also impacts the amount and perception of glare experienced by other drivers. The study was undertaken to evaluate the effect of correlated color temperature of automotive headlamps on driver visibility and comfort during night driving conditions. The experiment was conducted in a controlled laboratory environment using headlamps with different CCTs ranging from 3000K to 6500K. Participants from various age groups and genders were involved to capture diverse perceptions. Studies confirm that both CCT and illuminance (brightness) significantly affect driver alertness and performance. Lower CCT headlamps were generally perceived as more comfortable with lower glare but sometimes resulted in reduced object contrast. Higher CCT headlamps enhanced contrast and object detection but increased glare. The findings offer valuable insights for lighting manufacturers, vehicle manufacturer, and researchers working towards the evolution of glare free lighting systems.