In Mexico, when using a retorno , which is always a left turn, you stay in the left lane of the retorno, whether in Chapala, or on any highway. It´s like the people who consistently use the right hand lane to turn left onto the Carretera from Independencia in SAT, next to the licorería, when leaving the Superlake area, which is a one way street heading north onto the Carretera. If you are going to turn left there, stay in the left lane, don´t cross over to the right lane to turn left.
I know it´s not a perfect world, especially when it involves common sense.