A dual-mode bus is a bus that can run on power from two different sources, typically electricity from overhead lines and or ground level power supply and in parallel from an internal combustion engine burning liquid fuels or gas.  The term 'dual-mode' was first used for trolleybuses capable of running also on diesel for part of their route. Dual-mode operation is useful mainly for big vehicles which makes busses and trucks the candidates to be equipped with dual-mode propulsion systems. The distance from the logistics centre to the inner city is driven in a conventional way. Also there is the possibility to reach all clients aside the catenary system. In cities with slow air exchange and high emission figures caused by Diesel-powered vehicles there is a need to improve the situation and to reduce big pollution sources. Commercial diesel-fuelled vehicle are the main target because of their high NOx and PM emissions. The operation of a dual-mode bus is not bound to the electric system. 
Boston installed a dual-mode bus system on the Waterfront portion of its Silver Line in 2005. Electric power is required in the exclusive right of way that runs in a tunnel under Boston harbor; diesel power is used to run on city streets and highways. Seattle, Washington used a similar dual-mode bus system in its downtown bus tunnel until late 2004. Bergen also features dual-mode buses.
Found almost exclusively in public transportation use, articulated buses are usually around 60 feet long, while a regular articulated bus is 35 to 45 feet and has an increased passenger capacity. To safely navigate streets at the increased length, articulated buses are fitted with an extra pair of wheels and a flexible joint. Some models of articulated buses have a steering arrangement on the rearmost axle which turns slightly in opposition to the front steering axle, which allows the vehicle to negotiate turns in an arrangement similar to that used on long hook-and-ladder firetrucks.
The main benefits of an articulated bus are increased stability, lower roadwheel pressure, higher maximum speed, and compatibility with handicapped or elderly people. Bendy buses can be used in some cities with a tram network. Bendy buses are more suitable for mass transit purposes, because they have more doors for rapid exchange of passengers. The disadvantage is that they take up more road space. Articulated buses have been used in most European countries for many years. In Israel, articulated buses - commonly called "long buses" - are very common. The long buses are considered reliable and useful and they served in Israel since the mid-seventies.
A bendy bus is a long vehicle that usually requires a specially trained driver for maneuvering. The bendy is a total success in Budapest, Hungary, where the BKV city transit company has been running more than one thousand of them. people in some countries regard bendy buses as exotic, especially in Asia and the USA where any public transport are almost unknown.