"How many traffic signals are there in the Region of Waterloo?" As of January 1, 2009 there were 475 traffic signals with 434 controlled from the Traffic Control Centre. When were the Computerized Traffic Control Systems implemented?" During the fall of 1982, 138 intersections in Kitchener and Waterloo were brought under computer control. A new system customized to meet the changing needs of the Region of Waterloo was installed in the summer of 1994. Traffic signals in the City of Cambridge have been under computer control since 1986. "What happens to the traffic signals if the computer fails?" If the central computer should fail, the traffic signals are still operational and there should not be a noticeable difference on the street because of a special feature called the Time Based Co-ordinator (TBC). A TBC unit is installed at each intersection and contains a copy of the signal timing plans. The TBC unit will control the operation of the traffic signals until the computer failure is corrected. This feature was exclusively designed for the Region of Waterloo to ensure minimal disruption to the motoring public. "Why does there appear to be good co-ordination on some streets and not on other streets?" Good co-ordination for both directions of travel on two-way streets is not always possible. If this is the case, the direction carrying the highest traffic volume is usually favoured for co-ordination. Motorists may also notice changes in co-ordination throughout the day, which is due to changing traffic patterns. For example, one direction may be favoured during the morning peak period while the opposite direction may be favoured during the afternoon peak period. Co-ordination is set up to reflect the posted speed limit. Driving the posted speed limit may result in fewer stops. Slower traffic speeds caused by volume of traffic are also considered when setting up co-ordination. Co-ordination is usually set up for through traffic, however, in some cases, heavy turning traffic is favoured. "Why are there delays on the minor side streets?" On low volume side streets, vehicle detectors are placed either in or over the road which allow the traffic signals to rest in green on the major street until a vehicle is detected or a pedestrian pushes the pushbutton. The traffic signal will change at a pre-set time to minimize the interruption to traffic on the major street. This improves the co-ordination on the major street, maximizing the capacity of the road network. "Why doesn't the 'WALK' indication come on every time the traffic signals turn green?" At some traffic signals within the Region of Waterloo, a separate timing plan is provided for pedestrians and for vehicles. The pedestrian 'WALK' indication will only be displayed if the pushbutton is pressed. All intersections which operate this way have pushbuttons. Remember, PUSH THE BUTTON. "Why doesn't the 'WALK' indication stay on until I'm completely across the street?" The 'WALK' symbol has two purposes. It lets pedestrians know when to begin their crossing and it is timed to allow pedestrians to get approximately half way across the intersection. If you are p../images of the way across and the 'FLASHING DON'T WALK' indication comes on, complete your crossing as there is enough time to do so safely. "What happens to the traffic signals when an emergency vehicle is responding to a call?" Some emergency vehicles are equipped with devices which 'pre-empt' the traffic signals. During pre-emptions, a green indication is given to the street on which the emergency vehicle is travelling. When the emergency vehicle clears the intersection, the traffic signals revert back to computer control. Once under computer control the traffic signals will take 2 - 3 cycles to re-establish co-ordination. Some signalized intersections close to railway crossings pre-empt when a train crosses. After the train clears the crossing the traffic signals revert back to computer control. "Why do some intersections have left turn arrows and some have flashing advance greens?" The Region of Waterloo is in the process of replacing flashing advance greens with left turn arrow indications. Left turn arrows are needed to meet the increased demand for simultaneous left turn phasing which is not possible with flashing advance greens. The Region of Waterloo is maximizing intersection capacity by designing roadways and intersections to meet the future traffic needs of motorists.