On a 45mph road though that's a closing speed of 90mph assuming everyone's following the speed limit. It seems crazy to me to have opposing traffic sharing a lane at those speeds.
Opposing traffic is already sharing a lane at those speeds, that's what the double-white is about.
They aren't that wide and there's not a lot of traffic, the safe thing to do is in fact to stay toward the center and yield to the sides when opposing traffic is coming. This isn't that different.
Fair enough but you could say the same for the cyclists. Ultimately having traffic sharing a lane with high relative speeds is dangerous. It's dangerous for the cyclist at 15mph having a car come from behind going 45mph, and it's dangerous for the car having a car driving at them at 45mph. Both a 90mph collision between two cars and a 30mph collision between a car and a bike are likely to be fatal.
