Discussion
Many lights are turned on even when not being used. Figure 1 shows a freeway illuminated by bright lights during the night. Since the likelihood of a vehicle traveling on this freeway at 3:00am is low, the amount of light shown in the photo is excessive and wasteful. The systems that we use for controlling ALAN should be based on sensors and timers.
Figure 1 – Lights on but unused
Proposed Regulations
We propose that local governments create their own regulations for time of day use and the requirement of sensors and dimmers. The reporting and enforcement mechanism for would be the same as for color temperature and brightness. The State of California would monitor and enforce compliance using the satellite system for overall light pollution.