We see the odd one. There is no bypass. Most of the M 200 through PV requires that Trafico Pesado use the laterals. Trafico Pesado includes ANY vehicle with duals and any vehicle towing.
The part of the 200 that requires using the lateral is from (South bound) where as you approach PV the laterals begin (well north of the airpoar) to where the 200 turns left to head through the tunnels (Should be signed TEPIC and TUNEL) and the main road appears to go straight. DON'T GO STRAIGHT AHEAD here as you will end up in the very narrow streets into centro and the old town. Get off the lateral as you pass Plaza Las Glorias. Once you make this turn do not take the lateral unless you know where you are heading for as they stop without warning mid block!
Northbound, after the tunnels, watch for where the dual lanes merge with the dual lane road out of centro (on your left). Here you will for a few feet be back on 2 main lanes and you must immediately move right onto the laterals. There is a Pemex here on the right. The merge is almost always busy as all the buses and many taxis are trying to do the same. This is a 2 lane lateral; stay in the left through lane(--not the left turn lane!) at least for the first block or two as this is a very busy bus stop in the right lane.
(At the first light, right at the bus stop, the right turn there is to Calle Francia, where the Puerto Vallarta Trailer Park in located. (NOT Tacho's). IF you are going to PV Trailer park, make your turn from the Left lane in front of the busses as this intersection is very narrow and often crowded with traffic. We have done it several times in a 32' DP towing a car, it just needs slow and easy, care and patience.)
If you are continuing north either through PV or to Tacho's, just stay on the lateral. There are two lanes for most of it but they are very narrow here, watch the buses; one took our mirror off a couple of years ago.
For Tacho's turn right at Walmart; other wise carry on. Soon after Walmart the lateral becomes one lane then shortly after the end in a merge back to the highway. Yhe last block of lateral is pretty bad. If you see buses and heavy trucks leaving the lateral for the main lanes, follow them.