With traffic congestion becoming ever worse and local councils becoming more and more concerned about their towns and cities becoming grid-locked, especially the centres, drastic measures have been taken in order to ban cars from certain areas. A growing number of cities have added - at some considerable cost - manoeuvrable bollards. They lower when a vehicle fitted with a transponder approaches, then raise after the vehicle has passed. They work. There can be no question about this as residents in Cambridge and Manchester will no doubt testify.
But there are catastrophic consequences to bus service operations when an unsuspecting motorist unwittingly follows a bus as it passes over the bollards, which then raise damaging the car and causing grid-lock these schemes were designed to stop, as this video shows.