Speeding tickets in the UK are Fixed Penalty Notices. Sometimes the police offer the alternative to an evening training course in speed awareness, if the driver prefers. If the driver objects to the FPN then they can have their day in court, where you can face the accuser, which is The Crown here, so their legal representative. It's strict liability, so it's quite a barrier to be found not guilty. I've been driving since I was 12 years old and 50+ years later I've still not got a fine, penalty point or speeding ticket to my name, and I certainly don't think I'm a good or slow driver.

As for the millions of cameras: unless someone actually looks at the cameras then it's piling up temporary data 99% of which gets deleted unviewed.. If there is a murder then probably the police will take a look but the number of cameras now is self defeating : too many images, not enough resources to do anything with it.