The sound sensors are installed at equal intervals on the road pavements and these sensors are mainly put up for the sake emergency vehicles such as ambulance

The sound sensors are installed at equal intervals on the road pavements and these sensors are mainly put up for the sake emergency vehicles such as ambulance. When an ambulance is struck in traffic for more than 120 seconds, the sensors that are installed alongside the roads will sense the signal from the ambulance siren and sends the information to the ATCS. The ATCS then switches the signal colour to blue, which indicates the presence of an ambulance. By doing so the traffic can be cleared quickly before the ambulance reaches that particular area.