Portugal is very well served by low-cost carriers but when it comes to traveling within the country, unless you want to go to the islands, you are better off using the land transportation: train and bus.
If you are on a low budget, the bus is always a good option. Yes, it takes longer and not all roads are perfect, but if time is not an issue, this is the best way to explore the country. The bus network is well-connected but you cannot always relay on the timetables. Buses usually cover places which are not reached by trains.
Getting to Portugal by bus – from another country
The cheapest way to get to Portugal from another European country and vice versa is by bus. There are three companies, including Eurolines , which run services from other European cities to Lisbon.
Getting to/from Spain
The cheapest and fastest way to get from Lisbon to Madrid is by bus. Avanza Bus runs a service between the two capitals and there are two departures daily.
Getting around Portugal by bus –from one city to another
There are several inter-city bus companies offering connections in Portugal. All near-by cities as well as large cities in Portugal have direct connections to Lisbon. The main operator for long-haul routes is Rede Expressos . The company offers 300 routes within the country.
Getting around Portugal by bus – within a city
In Lisbon there’s an extensive bus service run by Carris . You can buy the tickets direct from the driver or from the machines in the bus, as well as from the outlets available in the city.
In Porto, STCP runs many buses on many lines, covering the city. However, the timetable is not very reliable. Tickets are €1.50 and can be bought from the newsstands.