The Skytrain (BTS) and Metro (MRT) network is a fast and affordable way to get around Bangkok. The system is easy to navigate and runs from 5.30am until midnight. There is also an extensive network of buses, but these are prone to Bangkok's notorious traffic jams. The most interesting way to get around is on the waterways of the Chao Phraya River, where numerous river taxis, long-tail boats and large waterbuses make most tourist sites easily reachable. Tuk tuks (colourful three-wheelers) are the standard way of making short journeys by road and are cheaper and quicker than regular taxis, but fares should be negotiated before boarding. Metered and un-metered taxis are air-conditioned, but passengers should be aware that drivers don't carry much change. Any taxi or tuk tuk can be hired for a day's tour of the sights. Bangkok also has free bikes for tourists for two set routes along the river; the east side goes past some of the biggest temples, while the west side goes through more residential areas.