A typical articulated bus is about 18 meters long. Its extra length comes from two rigid passenger sections joined by a pivoting articulation covered by flexible bellows, allowing greater capacity without making the vehicle impossible to steer through city streets.
The usual comparison is with a rigid single-deck bus, which commonly measures about 11 to 14 meters. An 18-meter articulated bus can therefore carry substantially more passengers and often has several doors to speed boarding. These vehicles are especially common on busy urban routes and bus rapid transit systems.
The figure is typical rather than an absolute limit for every design. Shorter articulated buses exist, while bi-articulated buses add another section and joint; those vehicles can reach roughly 25 meters. The 18-meter figure should also not be confused with the length of a conventional bus, a double-decker, or a specially regulated vehicle operating under a particular country’s road rules.