[azwiley1]

I can't speak for anywhere else obviously, but here is why I stay in the right lane here when it rains..

Road are not level and I have seen the water pool in the middle leaving the right lane dry(er).

I ride to the far inside part of the right lane, increasing my exposure to the creepiers coming out.

People here do not slow down, actually they drive faster and worse when it rains, so in the right lane I am out of their way and not holding them up when I need to slow down, break sooner, slower, etc.

Creepers are not too bad here when it rains because road junctions tend ot flood, forcing them to not come out like they normally would.

With the exception of the interstate, most of the roads here, at least that I travel are only two lanes each side and we do not have the concrete center divider like you reference unless it is a newly resurfaced road.

Ultimately, ride where you feel the most comfortable. I will change lanes as needed, wet or dry.