somerset police speed vans can catch bikes!!!

[Grahamm]

So how's this work, they measure your speed front facing and then record your plate after you've passed? Automated or some dude sat inside writing down the plate?

I've seen vans with a small CCTV style camera stuck on the side, so it will clock your plate as you pass.

BTW If I were you, I'd be interested at which point they actually saw you. AIUI they're supposed to look to see if you appear to be speeding before putting the detector on you, rather than simply scanning every vehicle that comes in to range (although I'm not a lawyer, so you'd better check this first!)