You'd probably get 2 NIPs automatically. But if you chose to go to court, I'm pretty sure (from lurking on 5ive-0 ) it would be treated as a single offence, provided that you could argue that you didn't stop in between, so both NIPs referred to the same journey.

Might save you 3 points, but then they'd bump up the fine and costs

 

It wasn't my car.

 

Quite a few years ago some biker got caught by 2 cameras along Southend sea front and argued in court that since he didn't drop below the speed limit between them then he was being done twice for the same offence. The judge was not sympathetic.