Chiang Mai's airport takes regular traffic from Thailand's major cities (including seven daily flights from Bangkok), as well as from other regional centres.
Buses also ply the route between Bangkok and Chiang Mai several times a day. The trip takes between 10 and 12 hours, depending on the money you pay. Trains also connect Chiang Mai to her southern capital.
Chiang Mai has only one city bus line of limited use, so most residents get about in swngthew (pick-up truck taxis) or on bicycle or motorcycle.
The best way to get around is bicycle. They are cheap to hire, environmentally friendly, give the lungs a workout and can be rented conveniently from many guesthouses and along the east moat. There are also hordes of swngthew, túk-túk (three-wheeled motorised taxis) and samláw (three-wheeled pedicabs) which are cheap enough but contribute to unnecessary traffic congestion and pollution. There are plans to initiate a mass transit system in Chiang Mai: a rail system would certainly help with the current congestion woes.