Confusion / consultation / clarification with Del about the route. He has an old tattered Guia Roji (2012)showing the route as 190 or 190D. The correct route from Cholula to Oaxaca is to take 150D out of Cholula through Puebla toward Orizaba (do not go over the pass to Orizaba) and then 135D down to Oaxaca. 135D will merge and become 190 as you enter Oaxaca. Stay on 190 toward Mitla through Oaxaca - on city street with traffic and traffic lights etc. DO NOT TAKE AN RV INTO CENTRO unless you are a small RV. The rest of the direction on the Oaxaca Campground website are correct. I do not know what newer Guia Roji might show. Guia Roji is too difficult to follow for us. Do not take 190 out of Cholula to Oaxaca unless you want a long and curvy mountain road with no shoulder which goes through towns and villages along the way and is 15 miles longer than the cuota route.