Although vehicles speeding and passing at dangerous times contribute to most of these accidents, if the police enforced the law requiring vehicles to pull over when there is a delay of 5 or more vehicles, there would be far less serious accidents and fatalities. 
I drive this stretch of road often, and have been stuck behind sight seeing drivers with as many as 15 or 20 vehicles behind them as an officer sits parked on the side of the road looking for someone speeding, but do nothing. This is not an excuse to attempt passing whenever they see a slim window, but the cop on the side who condones the traffic pile-up is also culpable.