And sometimes they are right. Not only unpredictable but also irresponsible. I was once driving on a 6-lane highway (3 lanes in each direction) and a young women on a road bike suddenly crossed all three lanes - went from the rightmost position on the right lane to the left lane - she probably suddenly noticed that she was about to miss her left turn (an intersection was approaching). She didn't look back, she didn't had a mirror, she didn't wear a helmet but she was wearing her headphones. She didn't signal a turn with her hand. She was extremely lucky that cars didn't hit her. But this is a whole other topic...