I was caught doing 85mph on the M6 Toll which has a 50mph limit. This was nearly six months ago and I sent off the relevant forms admitting to it but never heard anything back, so thought I got lucky until a summons arrived today.

Firstly why am I being summoned as opposed to just paying the fine and what are all possible outcomes? I already have 3 points on my licence and I've only been driving for 18 months.