The point of the LED bars is that they are to be used in emergencies/pursuits so the traffic around can instantly be aware of the high output led lights. These lights are provided by a famous US based company who also supply to the PD in the US. However, they dont keep the lights on all the time blinding people.
What the motorway police should do is to either install a small emergency light which can still alert people of the presence of a cop car up ahead OR simply use the police lights in an emergency ( which is how these lights are supposed to be used on a cop car to catch people by surprise who are driving rashly/overspeeding etc).
The thing I really hate is the display patterns that the lights do, just like those old toy cars with the flickering/strobing/moving lights.