Old Scottish cities like Aberdeen are fairly compact, so walking is a good way to get to many of the sights in the city centre. Longer journeys will require transport however, and many visitors choose to take advantage of the city bus system, run by First Aberdeen, when travelling to the suburbs. Tickets are sold by the driver, and both single-trip tickets and day passes are available (note that drivers do not give change). Taxis are also widely available from ranks dotted around the city or by phone, and though expensive this is the best mode of transportation in the evenings when the buses are less frequent.