Use the Panamerican Highway CA-1 which crosses the High Lands or the International CA-2, parallel to the Pacific Coast.
You can take a bus from many cities, including Guatemala City or Antigua, into Xela. While the local buses nicknamed "Chicken Buses" by visiting Yanquis, which are brightly painted old school buses, take these routes, they are long, bumpy, noisy and crowded, however they are cheaper between Q.20 and Q.35 depending on the route. However, for a few dollars more $7.50 US in the Summer of 2006 to travel from Guatemala City to Xela, ride one of the private bus companies, such as Galgos Greyhound style, which offers luggage storage, nice seats and quicker routes. Galgos has two daily departures from Guatemala City: at 8:30AM arriving at Xela around 12:30PM and 2:30PM arriving at 6:30PM. Try to arrange to arrive in the city well before dark.
If you are coming from Guatemala City the Linea Dorada is a great line, about US$9 gets you to Xela in about 4-4.5 hours with only one stop for lunch. Air-condition bus and movies included. This is a nice ride. Linea Dorada Guatemala City 16 Calle 10-03, Zona 1 Tel: 2415-8900 Guatemala City to Xela 8AM 3PM
Use a taxi when you arrive in Xela if nothing else than to get to the parque... about 25-30Q
Van shuttles are available to San Cristóbal de las Casas, Mexico and worth it as a van will take you to the Guatemala boarder and a van will pick you up when you come out of immigration taking you to the Mexician Immigration and then on to San Cristóbal de las Casas. There is a 1 hours time change and you leave Xela 8-830 am and arrive in San Cristobal 330-600 pm.
From San Cristóbal de las Casas there are buses (http://www.ticketbus.com....) to Mexico City, 13 hours on the luxury bus for 77 US dollars 884 local money. They take dollars but they have to be perfect without tears or marks.
The bus station in Mexico City is the TAPO and you can pay for and get an official taxi at a booth in the bus station. If you are headed to the airport it is 125P. Unofficial taxi may be less but may be more.
