Bus service within Portugal is comprehensive, punctual, and comfortable. Some luxury coaches even have TVs and food service, and all have a strict no-smoking policy. All that said, bus travel can be slow, though it's also a relatively inexpensive way to get around the country.
For major bus lines, you can buy a ticket online before you depart. For smaller rural lines, look for the schedules at the local tourist offices; if there isn't a ticket booth at the bus stop, you can usually buy a ticket at the closest café. It's always wise to reserve a ticket at least a day ahead, particularly in summer for destinations in the Algarve.
An under-30 card (www.cartaojovem.pt) for young adults and students should get you a discount of 10%–20% on the long-distance services. You can buy a card for €10 at post offices or youth hostels with a photo ID.
There are three classes of bus service: expressos are comfortable, fast, direct buses between major cities; rápidas are fast regional buses; and carreiras stop at every crossroad. Expressos are generally the best cheap way to get around (particularly for long trips, where per-kilometer costs are lowest).
Three of the largest bus companies are Rede Expressos, which serves much of the country; Rodo Norte, which serves the north; and Eva Transportes, which covers the Algarve and also has service to and from major cities, like Évora.
Eva Transportes. www.eva-bus.com.
Rede Expressos. www.rede-expressos.pt.
Rodo Norte. www.rodonorte.pt.