  Good nighttime road lighting is critical for driving safety. To improve the
quality of nighttime road lighting, this study used the triangulation method by
fusing "EEG evaluation + subjective evaluation + behavioral evaluation" to
qualitatively and quantitatively investigate the response characteristics of
different correlated color temperature (CCT) (3500K, 4500K, 5500K, 6500K) on
drivers' non-visual indicators (mood, alertness, fatigue and reaction time)
under specific driving conditions (monotonous driving; waiting for red light
and traffic jam; car-following task). The results showed that the CCT and Task
interaction effect is mainly related to individual alertness and reaction time.
Individual subjective emotional experience, subjective visual comfort and
psychological security are more responsive to changes in CCT than individual
mental fatigue and visual fatigue. The subjective and objective evaluation
results demonstrated that the EEG evaluation indices used in this study could
objectively reflect the response characteristics of various non-visual
indicators. The findings also revealed that moderate CCT (4500K) appears to be
the most beneficial to drivers in maintaining an ideal state of mind and body
during nighttime driving, which is manifested as: good mood experience; it
helps drivers maintain a relatively stable level of alterness and to respond
quickly to external stimuli; both mental and visual fatigue were relatively
low. This study extends nighttime road lighting design research from the
perspective of non-visual effects by using comprehensive neuroergonomic
evaluation methods, and it provides a theoretical and empirical basis for the
future development of a humanized urban road lighting design evaluation system.
