Daytime running lights are automatic, brake lights are automatic. Headlights and Taillights are not. As you can see in this photo, it seems evident that drivers don’t realize that their tail end is completely in the dark, and that daytime running lights are a fairly dim version of a headlight and don’t illuminate the road very well. In Reality, you need to physically turn on your headlights for your tail lights to light up, and to really see and be seen front and rear.