Am I correct in stating that you're complaining about a driver that lost control during highway corner and that it forced hundreds of people to adjust their weekend plans? Roads get icy during this time of year; hell, black ice is pretty prevalent already, and that's stuff you can't see in order to avoid. It's possible this girl was driving below the speed limit but still managed to hit a patch of black ice and was unable to gain control of the car before it crashed.
Don't ever drive the Coquihalla, then... you do that drive expecting at least a two hour delay going up (or down) the Snow Shed, due to accidents this time of year.
That said, I do agree that the speed limit on the S2S could be higher in a few sections, but this is starting the time of year when drivers need to start slowing down on that highway, regardless of posted limits.