Question Headlights must be in use: Answers Only when traffic is very heavy. Throughout daylight savings time. From one half hour before sunset to one half hour after sunrise. From one half hour after sunset to one half hour before sunrise. Explanation Headlights are required to be in use when a vehicle is being driven between one half hour after sunset and one half hour before sunrise. They must also be in use at any other time when visibility is less than 500 feet. Pass your DMV Written Test with flying colors Take me to the cheat sheet Montana This questions appears in the following tests: Montana Practice Test 13 Montana Practice Test 22