Similar to the function of taxi service worldwide, Thailand taxis are common, boldly coloured, and usually operate by taxi meters. Taxis are usually a go to method of transportation because they are familiar, spacious, comfortable, safe (to an extent), air conditioned, and reasonably priced. Although they cannot skip traffic as effectively as a motorbike, taxis are a reliable service. Taxi's can be hailed using the universal holler, and can be commonly found in most urban areas in Thailand.
MAKE SURE TO ONLY USE TAXIS WITH METERS, and INSIST THAT THE DRIVER START THE METER AS SOON AS YOU GET IN THE TAXI. Unscrupulous taxi drivers have been known to overcharge tourists and locals if the meter is not in operation.
Because of a preponderance of other lower-priced modes of transportation (Song Taews, Tuk-Tuks, motorcycle taxis, buses, etc.), taxis are not as common in Bang Saen as they are in other metropolitan areas. However, they can be found in front of Laemthong Bang Saen shopping mall (directly across Long Hard Road from Burapha University). If you negotiate, they may offer an attractive rate to take you Bangkok if they have already dropped a passenger in Bang Saen and are otherwise returning to the city empty.
You may of course order a taxi by phone to pick you up, though doing this in any other language than Thai can be a challenge.
Taxi meters base the total fare on time and distance travelled. Depending on the distance the passenger would like to travel, many meter taxi drivers are open to negotiate a flat rate price. Thailand taxis can be significantly cheaper than those in the west; for example, the fare to travel from Bangsaen to Bangkok (110km) in a metered taxi is usually somewhere around 1000-1200 baht (as of April 2015). Travelling from Bangkok to points outside the city is usually more expensive, while the meter rate for in Bangkok starts at around 35 baht (as of April 2015). Depending on the distance the passenger would like to travel, many meter taxi drivers are open to negotiate a flat rate price. Tourists should be aware that asking to fit more than four people in a taxi, could increase the fare prices, and any toll charges must be paid by the passenger. If you take a taxi from an airport it is also common to pay a 50 baht surcharge (as of April 2015).
Non-meter taxis are not as common as they once were, and should generally be avoided by visitors unless they know the routes and rates well.
Taxi's may not be the most environmentally sound choice of transportation, especially if the meter is running during Bangkok traffic, however the more passengers in a taxi, the lower the footprint.
While taxi's are generally a safe method of transport, the safety of passengers depends on the driver and the Thai traffic. Women travellers should also take note of the driver's name and photo posted in the taxicab. Photographing it with a smartphone and posting the image online on social media with a locational fix is a good strategy to ensure proper behavior by the driver.