They are a burden to the free flow of traffic because the incentive is to make as many people have to stop at those lights as possible. I have seen this in prac

They are a burden to the free flow of traffic because the incentive is to make as many people have to stop at those lights as possible. I have seen this in practice in my city. All camera lights are synchronized with the previous signals so that you are forced to stop just as you are approaching the signal at traffic speed.