I was at an intersectoin waiting to cross the street this evening. I saw a car coming and after it passed I was about to cross (very empty street and most people cross when no car around). Then all of a sudden there was a flash of white light from a delivery guy on the bike. I didn't even know he was coming because his front light was on flash mode and was completely dark when I looked at the car and surroundings, and he was in dark clothing. If he used a steady front light it would have been very clear.