Andrew Evans is hightailing it through Mexico and Central America in an effort to catch the Sea Lion, a National Geographic/Lindblad expedition that will take him from Costa Rica to Panama on his way to Antarctica. Here's a glimpse of what he saw of Mexico from the bus window.

The acronym ADO stands for Autobuses de Oriente, which is just what I needed: buses of the east. As much as I love Mexico, due to its vastness, I needed to find the shortest point between two distances--Reynosa in the north, and the border with Guatemala.

I had a ticket as far as Coatzacoalcos, right at the bottom of the Gulf of Mexico. We left at 9 p.m. and crossed the no man's land of northeastern Mexico where I slept on and off.

We stopped in Tampico at around four in the morning. I was impressed by what a clean and orderly bus station it had. Perhaps because it was empty. A cleaner polished the marble floor, two women sold Tampico souvenirs in a shop, and, in a corner, a young man tried to console his red-eyed and tearful girlfriend/wife.

Security was quite high--ADO bus lines advertise themselves as one of the safest bus lines in the country and before departing, a guard had come through the bus with a video camera recording each of our faces. Sticker seals were placed over all the luggage compartments underneath the bus and in Tampico, all reboarding passengers were kept behind a secure area. In many ways, the buses in Mexico were nicer than the ones in the United States. They all had more legroom and the seats reclined much further back so it was easier to sleep.