> That is not sane, it is dumb.

I understand where you’re coming from, but it’s perfectly sane if your legal system recognizes and accepts that speed detection methodologies have a defined margin of error; every ticket issued for speeding within that MoE would likely be (correctly) rejected by a court if challenged.

The buffer means, among other things, that you don’t have to bog down your traffic courts with thousands of cases that will be immediately thrown out.

So the sign says "100", the police read your speed at "112" but the device has a 5% MoE and in this case your actual speed was 107. Seems like you have exactly the same problem because the laws state the actual speed limit was "110" which you are under, despite being over the posted limit and the police reading you as over both the real and posted limits.