Map showing Bristol City Centre Evacuation Zones.Local Authorities have been asked to prepare evacuation plans for city centres following the 9//11 bombing. The evacuation of the whole city centre is extreamly unlikely (except in case of nuclear incident), but occasionally particular zones may need to be evacuated due to threats from flooding, terrorism etc.The zones are the result of discussions between Bristol City Council and the emergency services, which has simplified the evacuation zones from the previous 32 to 4 and provide mapping information to the city centre evacuation plan.It forms an important part of the city alert scheme where business have signed up to be warned of emergencies and incidents and can view the map if they are instructed to evacuate from one zone to another.