History of tram and light rail transit systems by countryAlthough tram systems date to the late 19th and early 20th centuries, many old systems were closed during the mid-20th century because of the advent of automobile (including bus) travel. This was especially the case in North America, but postwar reductions and shutdowns also occurred on British, French and other Western European urban rail networks. However, traditional tramway systems survived, and eventually even began to thrive from the late 20th century onward, some eventually operating as much as when they were first built over a century ago.
Transport collectif en site proprevignette|Le BHNS d'Aix, circulant en site propre (ici sa voie propre) à Aix-en-Provence Site (transports en commun) thumb|Contre-exemple de site partagé entre bus, taxis et deux-roues, véhicules d'urgence à Mannheim, en Allemagne. Un transport collectif en site propre (TCSP) est un transport en commun qui emprunte une voie ou un espace qui lui est réservé, de telle manière que ce mode de transport dispose de sa propre voie, son propre site, de façon à garantir une priorité sur le trafic automobile et permettre ainsi un gain de temps.
Capacitor electric vehicleA capacitor electric vehicle is a vehicle that uses supercapacitors (also called ultracapacitors) to store electricity. the best ultracapacitors can only store about 5% of the energy that lithium-ion rechargeable batteries can, limiting them to a couple of miles per charge. This makes them ineffective as a general energy storage medium for passenger vehicles. But ultracapacitors can charge much faster than batteries, so in vehicles such as buses that have to stop frequently at known points where charging facilities can be provided, energy storage based exclusively on ultracapacitors becomes viable.