Every technology has positive and negative consequences; these are some that we thought of:
System might be activated thru other types of radio communication due to increase use in wireless devices, will need to be very careful with this to avoid accidents.
A solar storm might make the satellites to malfunction and that could be a serious chaos.
Irresponsible drivers that do not service their not working sensors will be driving without traffic lights.
Repairing or replacing the windshields will be more expensive.
Workers in the traffic light industry (either manufacturing or maintenance) will loose their jobs.
Will save lives and will prevent injuries.
Will save gasoline and electricity, therefore will help our planet to love longer.
Will make evacuations (due to natural disasters) much faster.
Will save money in damage expense and medical bills. Will also save money in car insurance costs.
The sensors will be affordable, easy to install, and easy to customize for color blinded people, it will also save money in traffic light making and maintenance.