The flaw if you will, in your logic is even if the limits were higher there would still be thse whi feel they are too ow due to their "excelent mad skillz". those people will still choose to run, (if they would run now).
You blame the police for enforcement, which is their JOB, they didn't set the limits they merely enforce. Now having said that I believe the 400 series highways should be 120, BUT I am not a traffic engineer, so I have basis other than I "think" that speed would be acceptable. As I drove in this morning they were talking of the push tonight at the two community councils to move residential speed limits from 40 to 30 to "save the children and pedestrians" from higher speed collisions. But then they gave startling stat. in the years 2008 - 2013 91% of pedestrians killed in a collision with a vehicle died on ARTERIAL roads. These roads have a set limit now of 60 KM so do we raise those limits, (remembering this is where the VAST majority of speeding violations are given, and by your logic the limits are too low), to say 80 km? If I were a pedestrian or cyclist I would prefer not to be hit at all BUT if I am I would think I would prefer it to be someone travelling at 65 Km, (for fear of a ticket), then by someone doing 85 km.
Lastly, you complain now about the level of enforcement, (with an average 15 km leeway). But then admit places with slightly higher limits, NM, AZ limits are strictly enforced. So would the level of enforcement not actually increase? Given that on a 60 km road your given to say 75 before you meet enforcement. As opposed to an 80 km zone where you would get stopped at 82?? I woud prefer the leeway in the event of "human error" on my part.
Having said all this I would always, (when doing speed enforcement), stop a vehicle at 15 km over and discuss their driving with the operator. But would let more than 50% off with a warning once they hit 20 km over it was time for a financial hit to assist them in improving their driving habits. I will admit that the 15 km "cushion" is something that has been an unwritten rule and at one point was actually lower. WAYYYY back likely before you were born, coppers used to give you 5 MPH grace
Avoidable yes, but safely avoidable, no...riding under the flow of traffic is dangerous, and riding with the flow WILL eventually lead to a ticket...if that's not you yet, good on you.
Eastern states have atrocious drivers and low speed limits generally - they are more like Ontario...but western states like NM and AZ have reasonable (and strictly enforced) limits and yes they are much more enjoyable to drive/ride in.