A bit a pity as traveling slow thru a city is the best way to explore and see a city.
Luckily you can still find Samlors in some places like Phitsanulok, Khon Kaen, Chiang Rai and Chiang Mai.
In Chiang Mai you can even make a tour with a Samlor. For more information see Chiang Mai On Three Wheels
There are many kind of Samlors, for more information & Photos about other types of Samlors see Samlors in Thailand