Buses run routes on the main roads, but are often horribly crowded and noisy, signed only in Bengali and aren't likely to be of much use to travelers. But there are some buses which only take passengers if seats are available (at least in theory, but compared to the other buses they are usually not very crowded) and you have to buy a ticket at one of the bus counters in advance. During the rush hour, it can be difficult to get a seat and maybe you will have to wait in line with the other passengers. But taking the bus is cheap and once you found out which bus you have to take and where you have to get off, it is possible without speaking any Bengali. But going by bus takes usually more time than going by CNG and buses are also frequently involved in collisions. Save yourself a headache and take a rickshaw or CNG, or for long distances, a comfortable, air-conditioned bus or train. For more info on buses in Bangladesh, see the Get in section.http://wikitravel.org/en/Dhaka