By plane
Regular domestic flights operate between Guatemala City and Flores.
By Trolley
Guatemala City has a local trolley service aimed at tourists.
By train
There is a rail network, but aside from the occasional steam charter aimed at tourist groups, no trains, freight or passenger, have run since 2007.
By bus
It's hard to miss the colorfully-decorated buses that crowd the streets of major cities and highways of Guatemala. These are chicken buses, or camionetas in Spanish, and are a common form of travel for Guatemalans and a travel adventure for tourists. They are much cheaper than tourist vans or taxis and are usually very crowded, with three people squeezed into seats barely big enough for two children, and more people standing in the aisles.
The buses are often used North American school buses with the "Blue Bird" and "Ford" logos clearly visible. In addition to the driver there is usually a conductor standing in the door. The conductor collects fares, and from time to time jumps out to direct the bus through a blind intersection or around a tight turn. On the highways, the chicken bus drivers are aggressive, not hesitating to overtake in the face of oncoming traffic. Riding these buses on the steep highways of the Western Highlands is especially harrowing, but may be the most quintessential Guatemalan experience there is.
Bus conductors may sometimes charge out of country tourists more than the going rate. If you look to see what other travelers are paying you can usually avoid this problem, however, they often charge you the same as everyone else. Sending a message to the Guatemala tourism department, Inguat (http://www.visitguatemala...), will let them know of this problem.
You can board a chicken bus almost anywhere along its route. If you put out your arm, it will stop. You board and find a space to sit or stand. The conductor will come back to you after the bus is underway, and collect your fare. You need to recognize where your stop is, and move to the door in time. You ask the bus to stop, more or less wherever you want to get off.