Sorry for the delay. WEre you speeding?
You can do that if you want to.
However, you should understand that they do not need calibration lines.
All they need is two fixed points on the road. Calibration lines do no more than that.
If you challenge and lose then you will end up paying a costs order that could be quiet high.
I suppose at least you are not challenging expert evidence so that will reduce the cost.
You may challenge it and you may succeed.
They may not have two fixed points or they may not bother to summons.
You should understand the risk though.
Can I clarify anything for you?