While many jurisdictions still suffer under regimes like the one running BC, the trend is for speed limits that reflect reality. Those that do not have them are now observing the obvious and asking questions like "Why are speed limits set the way they are?".
Well the answer is that largely they are set with politics and not science as the basis. Our modern day foolishness, in good part, is due to the US rolling back their limits to a nationally mandated 55 mph and when we went metric in Canada, 80 km/h and 100 km/h were nice round numbers. The mantra that speed kills is bullshit and in the near future it will be difficult for the so called "experts" who make our transportation laws to keep uttering the phrase "speed kills" as safe driving reality coming from states like Texas and Utah, who have embraced higher speed limits, will hit the news wires and become more common knowledge.
But the other objection to higher speed limits, from those who just generally hate driving, besides that higher speeds make more noise (Danish concern) is that more fuel will be consumed.
The author of this piece in this morning's Pennsylvania based newspaper, a rider, suggests simply limiting displacement.