Rule 28: Staggered crossings (with an island in the middle) are two  separate Crossings  29. Crossings controlled by an authorised person.   Do not cross the  road unless you are signalled to do so by a police officer, traffic  warden or school crossing patrol. Always cross in front of them.  30. Where there are no controlled crossing points available it is  advisable to cross where there is an island in the middle of the  road. Use the Green Cross Code (see Rule 7) to cross to the island  and then stop and use it again to cross the second half of the road.  31. Emergency vehicles.   If an ambulance, fire engine, police or other  emergency vehicle approaches using flashing blue lights, headlights  highwaycodeuk.co.uk 17  4.Situations needing extra care 