Dynamic Roadways and in-Vehicle Lighting Conditions for Determining Mesopic Adaptation Luminance

This study examines the dynamic lighting conditions in automobile, at the driver's eyes, due to both roadway and in-vehicle systems. We measured the illuminance, luminance, and spectral outputs of several roadway lighting systems, as well as the driver's gaze direction and pupil dilation under mesopic conditions. The test vehicle was a 2009 Ford Focus, driving on selected rural, suburban, and city streets as well as expressways in and around Ann Arbor, Michigan, USA. The results could have important implications for the computation of target visibility under a known range of mesopic adaptation luminance on the roadway. They may contribute to strategies for design, deployment, and operational decisions for Smart Cities' lighting in the Intelligent Transportation System.