Buses

It is generally accepted that the longest "rigid" (ie: not articulated) buses will have three axles and be 15 metres in length. These come in both single and double deck variants - the latter often feature two staircases - unlike British double deckers which usually only feature the one stairway. Outside of London (where the front doors are for boarding and the centre doors for alighting) most British towns and cities use buses with just one combined entrance and exit doorway at the front, whilst elsewhere many towns and especially the larger cities use buses which have two or even more doorways, often with them all being for both boarding and alighting passengers.

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.

More "conventional" extra-large double deck bus designs exist too, yet despite their very high carrying capacity they too have not found favour with bus operators.

Another option is to use articulated 'bendi-buses'.

An alternative which has been popular overseas for many years and is slowly being introduced in Britain too is the use of single-deck articulated buses. In 99.9% of cases 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", "super-bus" or "LighTram" (a brand name used by the vehicle manufacturer "Hess" for their [electric] trolleybus versions).

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 passengesr on a short journey to stand (on the lower deck) when travelling on these buses too.

To cope with really large passenger flows extra long triple section buses are preferred.

In South America the Brazilian city of Curitiba has a very successful Bus Rapid Transit (BRT) system which uses a fleet of 167 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.

There is also a smaller fleet of 30 such vehicles operating in São Paulo (also Brazil) and this number will probably increase if a proposed BRT for this city also comes into fruition. If built this BRT system would use a fleet of these vehicles equipped with doors on both sides and the German O-Bahn (kerb guidance) system. (The German O-Bahn [kerb guidance] system is looked at on another page). However, whether it is actually built largely depends on whether the funding can be arranged.

Elsewhere double-articulated buses are used in just a handful of locations - and the fact that it remains possible to name the locations which do use these triple-section buses points to just how few in number those locations really are...

• Geneva, Switzerland which has (or will soon have) 15 such mega-buses, of which 10 will be mega-trolleybuses.
• Utrecht, Holland, which has a fleet of 27 megabuses.
• Gothenburg (Göteborg), Sweden, which has a fleet of 4 megabuses.
• The French cities of Nancy and Caen which use the specialist TVR buses that are styled to look somewhat like trams - see image below right.
• Santiago de los caballeros, Dominique, where (according to a French Internet discussion group) there are several (3 or 4).
• The reserved-lane transport system called "Phileas" which serves Eindhoven, Holland includes one double-articulated version of its distinctively styled buses which has been used as a demonstrator resulting in sales of 50 such vehicles to Istanbul, Turkey and two to the French city of Douai (the latter as part of a fleet of predominately single articulated vehicles).
• Dubai, in the United Arab Emirates, which in 2007 announced the purchase of 51 megabuses as part of a much larger purchase of a large fleet of water and road buses of various sizes (including 170 double deck buses!)
• Several cities also have single vehicles, many of which are demonstrators that have been lent to transport operators by bus building companies for evaluation in an attempt to stimulate vehicle sales. The list includes: Liège-Verviers, Belgium; Bucharest, Rumania (mega-trolleybus); Tehran, Iran; Jamaica, and Angola. As time progresses this list is expected to change.

Apart from these locations a number of cities are known to have been evaluating such vehicles, with several placing firm orders too. Perhaps the most high-profile of these is the Swiss city of Zürich which in July 2005 ordered 17 mega-trolleybuses for an overloaded trolleybus route, claiming that the 35% increase in passenger capacity the longer vehicles will offer will result in a more cost effective alternative to converting the routes(s) served to tramway. Also in Switzerland the city of Lüzern (which on some routes already operates trolleybus + trailer services - see "Road Train" below) is adding some double-articulated trolleybuses to its fleet whilst the city of St Gallen first chose to trial converting existing single articulated trolleybuses to the double articulated format. Apart from increased passenger capacity they wanted to do this because the new section would be of the low floor easy access variety, making otherwise high floor vehicles more accessible. However after trials with one converted vehicle they decided (in November 2007) to order 7 brand new double articulated 'LighTram' trolleybuses instead (as well as ten single articulated trolleybuses).

It is not impossible that double articulated buses would be used in a British city.

Trolleybus variants of these vehicles were suggested by the Electric Tbus Group (link to an external site which opens in a new window 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 apart from 'human politics' and those in power having the will to do so there is no reason why they could not be allowed for specific busy bus routes - subject to the proviso that they are physically capable of being used [ie: negotiating junctions, etc] on the roads involved. 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.

'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 has recently reintroduced trailers. Initially it was reported that this was only as a temporary stop-gap measure before converting an overcrowded trolleybus route back to tramway however it seems that they are now also looking at using double articulated LighTram trolleybuses, although it is not yet known whether as well as or instead of the trailers. The advantage of the double-articulateds would be that whilst they are 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 services, including the 'post buses' (which carry passengers as well as post) although these generally only use the trailers for luggage / post.

Trailers are used elswhere too (eg: Zug, Switzerland and Tallinn, Estonia), 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.

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 video clip of multiple-unit trolleybuses is also available. This comprises of three 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 had been stopped from filming the trams, so I had to be very careful. To see the film clip click either the projector icon or this link to download a 63 second video clip named 'Riga-tbus320.mpg'.