Buses

It is generally accepted that the longest "rigid" (ie: not articulated) buses will have multiple axles (either three or four) and be 15 metres in length. These come in both single and double deck variants - the latter often feature two staircases and three sets of passenger doors.

In London most buses use the front doors for boarding and the centre doors for alighting whilst most other British towns and cities use buses with just one combined entrance and exit doorway at the front. Outside the UK many towns and especially the larger cities use buses which have two or even more doorways, sometimes with them all being for both boarding and alighting passengers.

Halfway House - The 1½ Decker!

Even Larger!

The largest non-articulated double deckers were the 15 metre four axle double deck buses which were known as the N4032/4 Megashuttle. Dating from 1993 a small fleet of these were used in the German city of Chemnitz.

Depending on whether the vehicle had 2 or 3 stairways they could carry as many as 180/182 passengers - 99/101 seated (30 lower deck 69/71 upper deck) and 80 standing. To maximise manoeuverability all four axles were steered, even the drive axle (3rd) at speeds under 20 km/h. To facilitate this the entire axle including the air cushion support arms rotated.

The vehicles were withdrawn in 2004 because of a reduction in public transport demand due to the decline in the local economy after German reunification.

Another Option Is To Use Articulated 'Bendi-Buses'

An alternative which has been popular overseas for many years is the use of single-deck articulated buses. In the majority of places these vehicles will feature twin-section buses with one articulation, a handful places however also use triple-section double-articulated buses which depending on the local language (or version of English!) might also be known as "bi-articulated", "mega-bus", "superbus" or other names...

Understood to be the largest / longest design of single-articulated buses is the Brazilian Caio Millennium BRT Mercedes-Benz O-500 UDA. Launched in 2013, these are based upon a variant of the Mercedes-Benz CapaCity chassis and are 23 metres in length.

When initially introduced CapaCity buses were 19.54m in length and had a rated capacity of 193 passengers. In addition, because of their length their use in Germany required special authorisation based on the suitability of the roads it is intended to serve. However to meet a desire for greater capacity longer variants of these buses have become available. To assist with manoeuverability the 4th axle is steered.

Longer Buses: More Doors - But What About Seating?

Whilst it is of course possible for longer single deck buses to have just the one passenger doorway at the front, the lengthy delays at bus stops whilst everyone files past the bus driver (first to alight, then to board) would make such buses very unpopular.

Instead it is more usual for such vehicles to have multiple doorways located along the length of the vehicle and for these buses to be deployed on services which use off-vehicle ticketing and open boarding, so that passengers can use all the doorways for both entry and exit.

However there is also a trade-off in respect of seating capacity, as more doorways mean that there is less space for seating. Perhaps for short distance urban travel it does not matter as most journeys will be relatively short so that it will be reasonable to expect a higher percentage of passengers to stand.

Deckers Versus Artics: Which Is Better?

This is a question without a clear cut answer. Both have advantages and drawbacks.

Double deck buses give passengers (who travel upstairs) a grandstand view of the districts they are travelling through and can offer a much higher number of seats - albeit with the upstairs seating only being reach-able by able-bodied people who can climb the stairs. Critics claim that stairs on moving vehicles can be dangerous (they talk of the possibility of passengers falling if the stairs are used whilst the bus is in motion and it makes a sudden movement - braking, turning a corner, etc). Some transport planners say that especially for short journeys passengers tend to shun the upper deck and this leads to both overcrowding downstairs and under-utilisation of available space upstairs.

Articulated buses will usually feature several sets of doors spread out along the vehicle's length (usually three or four), the idea being that with passengers entering and leaving at all these doorways simultaneously bus-stop dwell times will be reduced - so speeding the service. Critics often question the wisdom of such long vehicles because of their increased land-take on crowded city streets where road space is a (perhaps very valuable) commodity but their advocates claim that even if the articulated bus is only half full it will still be taking far less roadspace than the cars that would be using the road had the bus not been there in the first place!

It is true that artics will have a lower seating capacity than deckers - but that is partly because of the space left clear for special needs access and also because with single-deck buses it is usual for many passengers to stand. Many modern double deckers also include "special needs" areas on the lower deck, and it is not at all unusual for passengers on a short journey to stand (on the lower deck) when travelling on these buses too.

Why Not Articulated Deckers?

With a capacity of 144 seated passengers it was thought that perhaps the ultimate in carrying capacity (for buses) would come from articulated double deck buses, such as these Jumbo Cruisers

However in the period 1975 to 1986 only a dozen of these double-deck single-articulated Neoplan N138/4 vehicles were ever built - and they were mainly kitted out as luxury coaches (rather than urban buses) for which comfort is as important a pre-requisite as overall passenger capacity.

To Cope With The Largest Crowds Extra Long Triple Section Single Deck Buses Are Preferred

In South America the Brazilian city of Curitiba has a very successful Bus Rapid Transit (BRT) system which uses over 170 three-section double-articulated (bi-articulated) buses as the backbone. This system includes 60km [37 miles] of segregated busway, 26 major and moderate size integration-interchange terminals, and seven different types of bus service including trunk route, express, local, feeder, inter-regional (to link different districts of the city) out of town (beyond the city borders) and more. They are all colour coded to make identifying buses easier. Only certain services use the double-articulated buses.

Note that these buses offer significantly fewer seats than double deck buses, and instead expect many passengers to stand during the journey. Often in crush-load conditions.

Curitiba has been using these high capacity (270 passengers) bi-articulated buses since 1992. To facilitate speedy boarding / alighting they have many doorways (sometimes on both sides) and call at distinctive kerbside tube style stations where passengers pay their fare on arrival so that when the bus arrives they are ready to board. The waiting area at these tube stations has a floor height which matches that of the bus so there is a safe and accessible step-free entry.

Where local laws permit them double-articulated buses are being used in an ever growing number of towns and cities. but as the aim of this website is to use sample locations to demonstrate possibilities for use elsewhere too, so it is not intended to even try and provide definitive lists of every location. Swiss cities use the electric trolleybus versions, most other places use liquid fuel powered versions. These include São Paulo, Campinas, Goiânia and Curitiba in Brazil and the busiest services of the TransMilenio BRT system in Bogotá, Colombia.

Prior to introducing double articulated buses to their towns and cities the Swiss investigated whether such vehicles would be viable and safe on their roads by building a prototype. They did this by taking an existing ordinary articulated bus and adding a new centre section. As seen below.

Nowadays several Swiss conurbations use these trolleybuses, with more planning to do so in the future.

Zürich found that the 35% increase in passenger capacity which its double articulated trolleybuses offer over single articulated variants represents a cost effective alternative to converting very busy trolleybus routes to tramway. Note the five doorways which along with off-vehicle ticketing help reduce dwell times at bus stops.

Lüzurn uses a mixture of both ordinary and tram styled double articulated trolleybuses. The ordinary styled vehicles came first, the tram styled vehicles are still being built (November 2016). First introduced on Rbus (Rapid Bus) route No.1 they are now also working on route No.2 with at least one more bus route destined to receive these higher capacity electric buses.

The Exqui.City buses are looked at in greater detail on the New Era Hi-tech Buses page.

The use of the longer buses in Hamburg has not been without controversy.

They are used on high frequency services (every 5 minutes) which pass along some narrow streets and very crowded areas. Even though they are driven by specially trained bus drivers and in crowded areas often carry an assisting driver they are experiencing a higher than average number of accidents.

It has been suggested that Hamburg would really prefer longer (21 metre) single articulated buses. However such vehicles do not exist.

Until 1978 Hamburg used trams and the idea was that a new U-Bahn (underground railway / subway) was going to be built to replace the trams, but this did not come to pass.

Possible Use In Britain?

It is not impossible that double articulated buses could be used in a British city. In the early 1990 the Bristol based bus company Badgerline [which later merged with another bus company and formed the First Group] demonstrated a double-articulated GLT vehicle in several British towns and cities. This was in connection with a proposal to use these buses on British BRT schemes, as alternatives to steel wheel trams. To avoid copyright issues it is not possible to show any images of the vehicle whilst it was here. The GLT is looked at on the New-era Hi-tech Buses page

Trolleybus double-articulated buses were suggested by the Electric Tbus Group for the proposed "West London Transit" scheme, as a more affordable alternative to a steel wheel tramway. (This was before the tram scheme was scrapped).

Technically these vehicles are illegal here (too long) but the real stumbling block is best described as "human politics". All it would need is for those in power (politicians, regulatory authorities, etc) to have the will to find workable solutions and then use their powers to influence the necessary regulatory changes. There is no other reason why they could not be allowed for specific busy bus routes / transport corridors - subject to the proviso that the extra long buses are physically capable of being used [ie: negotiating junctions, etc] on the roads involved. It should be noted that despite being extra long these buses are still shorter than many of the trams which are used on British roads. For instance, at 34.8 metres in length the double articulated trams in Sheffield are 10 metres longer than most designs of double articulated buses.

Apparently although under EU laws anything which is legal in one EU country can be deemed legal in all other EU countries too (with total disregard for local legislation) the EU rules for bus sizes specify shorter vehicles than these. Sweden, Holland (etc.,) are able to use double-articulated buses because the same EU rules allow individual nations the right to allow the larger vehicles within their own areas of administration.

Who Has The Longest?

It is probably inevitable that the friendly rivalry between our planetwide family of nations would result in several locations claiming to have built the longest double articulated buses. The Chinese claim that their 25 metre Youngman JNP6250G which is used on BRT services in Beijing holds this accolade.

Curitiba's biofuel powered 28 metre bi-articulated Volvo B12M (chassis) with a Neobus body. Note the five sets of doors!
Image & license: Luiznp / Wikipedia encyclopædia: CC BY-SA 3.0
http://commons.wikimedia.org/wiki/File:Curitiba_BRT_RIT_550PINHEIRINHOCARLOSGOMES_B12M.JPG



The five axle 30.7m AutoTram^® Extra Grand, in Dresden, Germany.
Developed by the Fraunhofer Institute for Transportation and Infrastructure Systems and constructed by bus manufacturer Göppel Bus GmbH in Thüringen.
Despite its length this vehicle still meets the German legal requirement to have a 12.5 metre turning circle.
Image from a Fraunhofer Institute for Transportation and Infrastructure Systems press release.

Double articulated buses were investigated for use in Australia (especially in Brisbane) but they are unlikely to be used, if only because of suggestions that if traffic regulations were to permit buses of this length then the same roads would have to be opened to the extra long multi-articulated "road trains", such as the fuel tanker seen here.

Road-Train

An alternative to both double decker and articulated buses is the 'road-train'.

Essentially the concept sees several independent road-going vehicles 'coupling up' just like a railway trains - except that they are on rubber tyres. The idea is not new, and in many cities has been superseded by articulated buses, but is still favoured by some bus operators because by adding the trailer vehicles at busy times, for sporting events, exhibitions, etc., an enhanced flexibility is gained to 'tailor' capacity to suit short-term increases in demand.

Usually only two vehicles will run in multiple, although rare instances of 30 metre-long 'road-trains' (with two trailers) have been known to exist too. At one time some european bus operations included 'road-trains' which featured through corridor connections, allowing passengers to pass from one vehicle to the other during the journey. Regrettably however photographic evidence is lacking.

Amongst the advantages of 'road-trains' are that compared to a pair of 'solo' motorbuses there is a very significant reduction in fuel consumption (as much as 75% has been noted) and a saving in staff costs. 'Road-trains' work best with 'off-vehicle' ticketing systems, otherwise any financial savings from fewer staff will be eroded by the need for an on-board conductor. Surprisingly, despite being unpowered the special trailers are not necessarily any cheaper to buy than new motorbuses, although they should have a much longer working life.

Nowadays Lausanne is one of a handful of Swiss cities which still uses trailers. To cope with increasing demand Lüzern reintroduced trailers, albeit as a temporary stop-gap measure before converting an overcrowded trolleybus route back to tramway. However they have now adopted a different solution and are also using Hess double-articulated LighTram trolleybuses, some of which have a special TBRT (TrolleyBus Rapid Transit) styling, as seen elsewhere on this page. The advantage of the double-articulateds is that whilst just 2 metres longer than the rigid trolleybus + trailer combinations they can carry 20 more passengers. The Swiss also use trailers on some inter-urban and rural bus services, including the 'post buses' (which carry passengers as well as post) although these generally only use the trailers for luggage / post.

Nowadays the use of bus trailers has become relatively rare with a 2014 German survey finding that in 2015 there were just 232 trailers in passenger service throughout the European continent. Since the aim of this website is to use sample locations to demonstrate possibilities for use elsewhere too, it is not intended to even try and provide definitive lists of every location.

A variant of the road-train used to involve twin-axle rigid trolleybuses running in multiple-unit, with both vehicles powered but under the control of one driver. This was commonplace in Eastern Europe and the former Soviet Union, although nowadays all examples of this have now been replaced with articulated (bendy) buses.

For multiple-unit operation the front vehicle did not use its trolleypoles and was both physically and electrically connected to the rear vehicle. The coupling between them worked by means of a drawbar which was connected to the steering arm of the rear bus - so that it just followed the driving one. Effectively therefore the principle was very similar to a road vehicle pulling a trailer - except that here both vehicles were powered. Once coupled the twin-set combinations would normally remain coupled (unless the workshops disconnected them). So the rear vehicle would not normally drive 'solo'. For safety pedestrians were prevented from walking between the two vehicles by means of flexible 'gates' - as seen in one of the images, below.

Clicking any of these four multiple-unit trolleybus images will lead to a dedicated page showing more (and larger) images in a popup window; alternatively clicking here will open the page in a new full-size window.

These images come from Riga, which is the capital of the Baltic state of Latvia.

Note how the first vehicles' trolley arms are lowered, and the concertina gates which prevent pedestrians from walking between the two vehicles. Since these photographs were taken Riga has replaced these multiple-unit 'rigid' buses with articulated buses.

A short film showing some multiple-unit trolleybuses (as well as some trams) in Riga has been placed on the ‘YouTube’ film / video website and can be watched (in a new window) by clicking the projector icon or the link below. The film comprises of a few different sets of images, all hand held, and all of the 'snapshot' variety, as I was not sure whether I should have been filming at all. At one time I was stopped when filming the trams, so I had to be very careful.
http://www.youtube.com/watch?v=fGiVhbPAgnE.

Another option comes in the form of articulated lorry tractor units pulling passenger-carrying trailers which at the front fit over the tractor unit's rear axles. However the perceived danger of a passenger-laden semi-trailer dislodging from its tractor while under way has resulted in regulations being introduced which ban passengers from being caried in this type of articulated bus, especially in Australia, Canada and the USA.