Dhaka is huge, and the traffic is terrible. As I said before, to get from one side of Dhaka to the other takes about 3 hours. To make this commute, excluding the public buses (which you should stay away from) you basically have 3 choices for transportation. Which of these options is the best for any given journey across the city depends on 2 main factors.
First, how far are you going? If you need to traverse the full length of Dhaka, then you should definitely rule a rickshaw out. You want to be in some sort of motorized vehicle—otherwise it will take all day. If you are going somewhere that is not far from the beaten path and its close enough that crowding into the back of a hot truck bed sounds okay, a laguna may be your best option (and certainly your cheapest). However, in all other cases, you may need to get an CNG (or auto-rickshaw).
Second, how narrow are the streets going to be during your journey? The problem with Dhaka is that many of the streets are too narrow for anything other than Rickshaws (and walking). For this reason, it is not uncommon for a CNG to drop you off at the entrance to a particularly dense neighborhood. If your destination is still a long way away, you will need to catch a rickshaw from there. It's normal to changes vehicles once or twice in the same journey.
So now we've touched on Rickshaws, CNGs, and Lagunas—but what are these things?
1. Rickshaw
This is essentially just a bicycle that tows a small wooden seat with a colorful but low-hanging overhang, kind of like a very ghetto version of the roof of a convertible. Because it's being towed by a human being (who is probably not Lance Armstrong) rickshaws are to be used only for relatively short distances. Transportation via rickshaw is going to be slow. These operate mostly for purposes of Dhaka’s back alleys, where bigger vehicles cannot go. rickshaws can go anywhere. Even the tiniest alleyway.
How much is a fair price for a rickshaw ride? In a city as big as Dhaka, it's hard to say. It's difficult to judge distance from the back of one of these things, so I think the best thing you can do is ask a local the correct price for the journey you're about to make before you embark. Most people in Dhaka will be able to tell you within 20 BDT (0.24 USD) the exact price of any given journey across their city.
2. CNG
“CNG” stands for Compressed Natural Gas. In India, similar vehicles are referred to as "auto-rickshaws." In Cambodia, they call these "tuk-tuks." Whatever you want to call it, it’s basically rickshaw with a motor. When you ride one of these, the driver will close the "passenger door" and you will be enclosed by a tiny cage. It’s pretty claustrophobic in there. CNGs tend to be used mostly for longer distances. These little guys might not look like much, but they will drive on Dhaka's version of the "highway," and that's when things get pretty loud. From the back of a CNG on a major road, you often need to yell to be heard because of the roar of the motor, and honking, yelling, and bells that surround you.
How much is a fair price for a CNG? Well, the first thing you should know that it's going to be well-above the price you would pay for a rickshaw. These guys need to pay for gasoline. However, again, because of the sheer size of Dhaka, it's difficult to give any concrete guidelines on how to estimate the price of any given ride. Again, I think the best thing you can do is ask a local the correct price for the trip you're about to make before you leave. It could even be the person working the front desk of your hotel. Most people in Dhaka will be able to tell you the exact price of any given journey across their city, within 20 BDT (0.24 USD) .
3. Laguna
"Lagunas" are basically D.I.Y. versions of public buses. They are pick-up trucks with benches and roofs installed over the back. They are on set routes already, so people jump on and off of it as it moves down the street. This is by far the cheapest option available to you, but it’s pretty unlikely that you’ll be able to get yourself where you need to go if you don’t speak Bangla. These things get pretty toasty and crowded on a hot day, so I would not recommend this for the inexperienced traveler. If you have friends or coworkers in Dhaka, you might want to ask their help the first time you catch one of these.
How much to catch a ride on a laguna? To a certain extent, this depends on how far you need to go. Recite the name of the place you are going and they'll tell you the price. However, for most distances, it shouldn’t be more than 30 BDT (0.38 USD). Like riding the bus, these things pretty much carry a set price for any distance. However, if your destination is ridiculously far away, the price may rise slightly. You'll pay the man or kid collecting money (they might be standing on the back of the truck like a garbage man or sitting in the passenger seat) and then hop in the back. Stay vigilent to make sure your don't miss your stop!
ADVICE On Getting Around Dhaka:
Have exact change.
A really common way for you to get ripped off is for a rickshaw-waller to just try to not give you back your change. Don’t worry, it won’t be a confrontation. They will smile and talk to you in Bangla saying “come onnnn, you don’t want your change, come onnnn, pleaseeeee…” and so on and so forth. It's a pity play.
If you find yourself in this situation, and you really want your change, you have basically have 1 option: make a scene. People will probably stop and start staring, and that's okay. That is actually what you want. You’ll be surprised how fast a local will step in to mediate, telling the rickshaw waller to give you correct change. However, before you do this, you should be warned that rickshaw-wallers have a very low social status in Bangladesh. When the "nice person" who came to your rescue is sticking up for you, the subtitles probably pretty nasty.
So it's kind of a sticky situation. It sucks, but sometimes it’s the only way to not get ripped off. HOWEVER, you can avoid the whole thing by just having exact change in the first place. So have exact change! Don't leave your rickshaw-waller like Dr. Who up there.