I would totally agree with you if I trusted the government
But not only do you have to trust the government now (and you likely should not), you also need to trust the government far into the future (which you absolutely cannot do) because the tools will still exist.
Don't accept tools that are also strong weapons for oppression.
It's the widespread remote camera installs that are the main problem there. If they kept data locally and had to be collected by hand, it might be fine - that's difficult enough to grow to monitor everyone all the time. Aside from using film though, I'm not sure how that would be achieved.
(To be clear, I really do think we should be prosecuting speeding (and tailgating) MUCH more than we do. Far more death and damage occurs from it than we should allow. But ubiquitous networked cameras are not the way we should do that.)
How else should it be done? I think they're going to pick the cheapest option most of the time.