Arizona Route 19 South

Planning a trip in late March to Green Valley, Az. in my motorhome. What is the traffic like going south during the day? How many lanes? Speed limit? Thanks for any help.
Arizona Route 19 South

Not that long of a drive from Tucson. Half hour at most. 4 lane highway 75 mph speed limit gentle incline all the way. Traffic not bad enough to cause problems. New overpass being constructed just as you enter Green Valley and traffic goes to 1 lane but have never been in a line to go through.