Fifteen plus years ago rear lights had two modes solid and flashing. The flashing mode would provide 2-3 times more time than the solid mode. I consider myself efficient, so I used the flashing mode. Talking with other cyclists I learned that the flashing mode attracts drivers vision more than the solid mode, therefore they would stare at it. Wherever you look is where you go. Cyclists do not want to attract drivers attention. Keep the solid light mode for safety. Unfortunately, today lights have many tempting flashing modes, they are all troublesome.

My favorite lights have been knog, they are small, waterproof, and have phenomenal brightness.