Automated speed cameras are fairly common in the US but are obviously not a surveillance network.
Two, they're pointed exclusively at roads.
Three, their outputs don't show up in court cases as evidence, which itself dramatically reduces the danger (even if they potentially could maybe support parallel construction)
Speed and stop cameras are very very good and should be virtually everywhere with extremely strict control on their outputs.
In any case, an evidence modality that can only be used via parallel construction is still far, far, far less risky than one that can be freely introduced in court.
I’m also going to guess that there are significant access controls on the systems in the UK that would prevent things like tracking an ex, or cops using ALPR to see if you have visited a healthcare facility that offers abortions among its other services (both real examples).