The sheer size of Brazil makes local flights the most convenient method of travelling between major cities. São Paolo is the major connecting hub. Travellers who plan to fly to several destinations can make use of a Brazil Airpass, which allows for flights to up to nine local destinations. Buses are the main alternative, with services linking all the major cities. The schedules are fairly reliable, and buses are clean and well-maintained. Buses are also a primary mode of transportation within the cities. Taxis are the most reliable and safest form of transport at night. Taxis in major cities generally will use meters; however, in smaller cities a price needs to be arranged beforehand. In the rural areas of the Amazon, river travel is still used, and in large sections of the Pantanal rainforest, it is the only way of getting around. Car rentals in Brazil are relatively widespread; however, drivers should take care as the rules of the road are often treated more as suggestions in Brazil. While Brazilian trains are primarily used for freight, there are a few scenic passenger train routes.