Comment by mnw21cam

PSA: Flashing someone is never a signal that you're giving them priority. That is explicitly forbidden in the highway code and dangerous. Flashing someone, like using the horn, only means "I'm here, just in case you didn't see me". If someone flashes you, you should make your own determination whether it is safe to perform a manoeuvre, making no assumptions about anything that the person who flashed you might be seeming to be promising.