A common sight at traffic lights are screaming ambulances struggling among a multitude of vehicles.

Why not have clearly demarcated tracks at all traffic lights through which an ambulance can move forward in case that path is stopped for traffic with red light?

This means in a four way junction, a certain space is marked as track on each of the four roads and just as an ambulance arrives those vehicles on that track move over to some other space(which also may be shown with arrows) clearing the way for the ambulance