I think you can ride the whole way from Alaska to Patagonia on the PanAmerican Highway. Some people, possibly most, do but it’s considered bad form. Sometimes you have no choice, like through Panama. Sometimes you can get around it but the route would be rediculously contrived, like Costa Rica. Most of the time it can be avoided without being silly. It’s useful for some of the better border crossings and that’s when most riders jump on it for a while.
So Hans, a while back, surprisingly tells me that the PanAmerican between Riobamba and Cuenca is one of the best paved rides in Ecuador.
That’s convenient because I want to head south quickly now.