Segregated Trolleybus system in Quito

A tram stuck due to inconsiderate parking

One Lyon Trolleybus overtaking another


• Trolleybuses (Tbuses) provide all the benefits of a tram combined with the flexibility of the bus. Unlike diesel buses, Tbuses do not give off any exhaust fumes - they are powered from overhead electric wires, just like a tram. But whereas the tram needs rails, the Tbus glides smoothly along on rubber tyres and only needs the ordinary road surface.

This means that, where street-running is required (when the vehicle mixes with ordinary traffic) there is no need to have massive disruptive roadworks during installation, as there would with a tram system. Tbus networks are therefore much cheaper and quicker to install than tram networks - in many cases, all you need is the overhead electrical system (poles, wires and substations) and the vehicles themselves.

Of course, this doesn't mean that Tbuses have to mix with traffic. You can have a segregated Tbus route just as easily as a dedicated tram line (see picture, top left) . In Leeds, lots of land has been set aside for tramways - this could be used for Tbuses instead.

In some places where they have trams, problems have been caused when the line gets blocked by broken down or illegally-parked road vehicles. In these cases, the tram is often stuck until the obstruction can be removed. Tbuses don't have this problem because they can overtake without leaving the overhead wires. However, if the blockage is so bad that the whole road is obstructed, then modern Tbuses are able to disengage from the overhead wires altogether and use an alternative route (just like an ordinary bus) by running from batteries. [more...]

Tbuses are the acceleration 'kings' where public transport is concerned. This is because Tbuses have the twin advantages of an electric motor (which has greater 'torque' than a diesel) and rubber tyres (which provide better traction than all-metal tram wheels). Tbuses can also decelerate more quickly than other types of vehicle. This means that the Tbus can stick to a tight timetable more easily than its rivals.

Because the Tbus uses an electric motor, it is much more energy efficient than a diesel and is therefore a great deal kinder to the environment - especially if the electricity used is from renewable energy sources. Also, due to the fact that Tbuses are usually much lighter than equivalent-capacity trams, they use less energy than trams, too. [more...]