Cyclist, especially those who feel the need to dress head to toe in florescent lycra to pop to the local shop for a pint of milk, hate their lack of respect for other road users.
Maybe due to the bar man's trick of livening up a flat looking lager with a pinch of salt. Seen many a pub with a salt cellar underneath the drip tray.
When it comes to speed achieved on the roads, most people don't seem to understand what the word limit means. This thread is further evidence of that.