When I went to Mexico, I could find these type of roads, normally very quiet, some people told me was a bit dangerous if you are a tourist, but actually I didn´t have any problem, the people were very nice and helpful, in the villages by the road where very kind.
Tulum was a city of Mayan culture in the state of Quintana Roo (Mexico), in the coast of the Caribbean Sea. When I was there last year I saw the archaeological monument, as usual in this place it was hot, and you can see iguanas sunbathing quietly, the place it is amazing, even the beach was dirty and I couldn´t have access.