The two-lane road to Chichen Itza was extremely overgrown. The jungle had completely taken over the shoulder. Every time I heard a car or truck approaching from behind, I had to pull off to the side of the road and let them pass.
The heat was also a major issue. Mid-day, I had to pull to the side and sit under a tree. Again, I was suffering from heat exhaustion.
I was eventually able to continue but decided to stop for the night in the colonial city of Valladolid.