The Puerto Vallarta info below is primarily for those who are not familiar with it:
In Puerto Vallarta, the lateral rule only applies to the Northern section of the 200. The southern part, from where the highway goes towards El Tunel and the road that leads through centro and to the old town splits off, the laterals do not need to be used, and in fact should not as they are not continuous and you may find yourself heading somewhere you really don't want to be in an RV! Such as into a loading bay! Nor do you want to be in Centro with and RV.
Southbound, (if going south through the city) stay on the lateral(left lane, though NOT the left turn lane)until just past Plaza Las Glorias then follow the exit(left)off the lateral onto the main lanes. In a VERY SHORT distance there is a traffic light which includes a left arrow. You need to turn left here. This is the main 200 which takes you through the tunnels and into old town for a few blocks where you turn left again to the 200.
Driving on the laterals in PV, which are for the most part two lanes, it is permitted to be in the left lane; the right lane will take for ever as all the bus stops are in the right lane. If the right lane is light traffic I will stay right when I can. Note these lanes are very narrow. We lost a mirror here many years ago.
Other locations: Zihuatanejo: Laterals not required and best avoided UNLESS you are turning off
Morelia: The periferico is multilane,but still very very busy. If I recall correctly for most of it there are no laterals. Good news; traffic to and from Patzcuaro and/or the Pacific Coast there is a new toll road off the 15D north f the city that misses Morelia completely!
Queretero; Laterals not needed. Except for turning off.
As stated by others watch for the No Duals signs OR Trafico Pesado Obligatorio. (Heavy Traffic Mandatory)
NOTE: Trafico Pesado = Heavy Traffic (Anything with duals OR pulling a trailer)
Trafico Pasado = Through Traffic. Big difference!
