If you've been on a streetcar in San Francisco or a trolley in Philadelphia, you've ridden a tram. The word tram was originally a Scottish term for the wagons that are used in coal mines, stemming from a Middle Flemish word meaning rung or handle of a barrow.
A tram (called a streetcar or trolley in USA) is a rail vehicle that travels on tramway tracks on public urban streets; some include segments on segregated right-of-way.
Also known as streetcars or light rail (there's debate around the nomenclature, naturally), trams offer riders speed and reliability, are cheaper (though not cheap) and easier to install than rail, and offer side benefits like no emissions and can help underpin neighborhood regeneration projects — though the latter's ...
I think the main difference between a tram and a train is that a train (heavy rail) has a dedicated locomotive that carries no passengers or freight (besides the operator) but tows unpowered passenger or freight cars, while a tram has just one or two powered passenger cars with an operator's cabin at each end.
The advent of personal motor vehicles and the improvements in motorized buses caused the rapid disappearance of the tram from most western and Asian countries by the end of the 1950s (for example the first major UK city to completely abandon its trams was Manchester by January 1949).
Pay as you goYou don't have to work out the cost of your journey in advance. You can pay as you go using contactless (card or device), an Oyster card or a Visitor Oyster card. It also offers great value as pay as you go is cheaper than buying single tickets and you get daily and weekly capping.
Some disadvantages include the fact that they are bound to their rails, if there is an obstacle on the track or if the track is blocked the tram just can't move.
Twelve of the tram systems studied fall under this category, with Lyon emerging as the leader. The tram system in Lyon, which was set up in 2001 and stretches across more than 60 kms in the city, received a score of 71 out of 100 averaged across all performance indicators.
Conventional electric trams are operated in street running and on reserved track for most of their route. However, on one steep segment of track, they are assisted by cable tractors, which push the trams uphill and act as brakes for the downhill run.