It was even announced that the ceremony has been moved forward by half an hour as a result of the enhanced security, to avoid clashes with the lunchtime rush hour. Changing the Guard which in the winter usually takes places on alternate days has also been changed, moving to fixed days of the week so businesses can plan for the closures. On December 21 Scotland Yard began closing all roads around the Palace, rather than using the previous system of rolling road-blocks, bringing forward a proposed three-month trial of the enhanced measures. No traffic is allowed in the area between 10.15 and 11.45am on the days the ceremony takes place. The ceremony at Buckingham Palace is far older than the palace itself. The Guard at Buckingham Palace is usually carried out by one of the five Foot Guards Regiments of the Household Division – the Grenadier, Coldstream, Welsh, Irish & Scots Guards. They are identified by the number of buttons on their tunics and the plume in their bearskin caps.