Most visitors to Ashgabat travel with a government-assigned guide, which effectively means the guide arranges transport. Taxis are available and inexpensive by international standards — always agree a price before getting in, as meters are rare. A new Ashgabat metro opened in 2011 with two lines, though foreigners have reportedly been prohibited from using it at various times; check current regulations with your guide or tour operator.
The city is spread out and not walkable between major sights — distances are large by design, as the marble boulevard aesthetic requires vast open spaces. The main tourist sites (the National Museum, the Turkmen Carpet Museum, the bazaar, the monument complexes) are spread across different parts of the city. Having a guide with a car is effectively mandatory for independent exploration. Cycling is not practical given the heat and distances. Walking is pleasant in the central parks and fountain zones in the early morning or evening.