Very important all over Sri Lanka are the Three Wheelers or widely called Tuk-Tuks, who also rule in Colombo by offering the by far most flexible transportation.
In fact, most buses are a mess in Colombo, what is giving countless Tuk Tuk drivers a great business opportunity, in particular when dealing with Westerners, who are not used to discuss prices.
In the worst cases Tuk Tuk drivers are simply driving opposite ways to extend the fare by pretending to be new in Colombo.
Even many Sri Lankan ladies would not dare to use an unknown Tuk Tuk driver, though one has to say, that a many of them are doing a very good job while risking their life and health under mad traffic and air conditions.
In Sri Lanka things run different and it makes sense, to tell the driver what he may get for a lift and to find out about regular rates before hiring one of them.
After some time one might get a bit of a feeling for what one may call "normal pricing" just to make using "Tuk-Tuks" eventually some kind of enjoyable.
Once a very good Kandyan Tuk Tuk driver was raving about some $50 that he had just made from selling a case of cigarettes to some drunk Russian tourists.