While turning, they should be informed

Ok, so here it is. Basically, when the care wants to turn right or left, as soon as the driver turns the signal on a hologram is projected on the lane he wants to turn to, indicating a statement "this vehicle will turn in *insert count down*" so the other vehicles in the lane can either slow down or speed up, in case they're going fast. It can also be modified in a way that it sensors the speed of the cars in that lane and if the driver can turn or not.