light rail? This is important because we need to save energy by making lighter transit cars…
With the stop and starts its takes more inertia to move a transit car as opposed to a automobile on the highway which just moves…Our city buses are about 20,000 lbs (I think) and the old PCC trolleys were only 25,000 lbs (The 5,000 lbs for the rail axles?)…
So if a light rail vehical is running with 40 passengers mid day thats about 1,300 lbs of weight per passenger as opposed to 2,500 to 3,200 lbs for the avarage auto car…but if the car has 2 people that autoweight per passenger is devided in half so its about the same energy requirments to move a passenger by a modern light but really heavy trolley car as it is for a 2 person SUV in the car pool lane…and without the energy waisting stops and starts either
“Light Rail” is more a mode of transit than a particularly "lightweight’ passenger car (definitions of which have changed steadily over the past sixty years if not more!).
When we speak of “Light Rail” (Muni Metro in San Francisco, Charlotte NC’s new LYNX), we think of a mode of transit that often runs on its own ROW (not always), uses dedicated station shelters with ticket-selling machines (there are exceptions to this too). The more modern systems generallly collect power from a flat pantograph and an overhead energized wire. Here, too, there is an exception in the diesel-electric LRT; the only example I for I can think of is the Camden, NJ to Trenton route. There is generally no interaction with freight.
“Heavy Rail” includes most freight and passenger lines (commuter and Amtrak). Sometimes the dominant idea was locomotive-hauling-coaches but that has never been the case all of the time (think of Edison cars, the old I.C. electrics and m.u’s that go back to the first couple of decades of the 20th Century). OTOH, some NJT lines seem to be going over from m.u. or self-propelled rail to locmotive-drawn (ALP-44’s and successors). Subways, Chicago’s “L” and rapid-transit systems like BART and its little brother, the Washington D.C. Metro, are also heavy-rail.
It is my understanding that what really separates the “light” from the “heavy” is the weight of rail used safely. It isn’t as simple as weight of the rolling stock, is it??
Generally “light rail” uses one-fare or zone fare systems and many of them are on the honor system; you might get a ticket if you’re ticketless on the light rail, but conductors do not go thru collecting tickets as they would on say, a commuter train.
To get an idea of modern light rail, try siemens.com. To get an idea of heavy-rail commuter, go to metra dot com.
“Light Rail” is more a mode of transit than a particularly "lightweight’ passenger car (definitions of which have changed steadily over the past sixty years if not more!).
When we speak of “Light Rail” (Muni Metro in San Francisco, Charlotte NC’s new LYNX), we think of a mode of transit that often runs on its own ROW (not always), uses dedicated station shelters with ticket-selling machines (there are exceptions to this too). The more modern systems generallly collect power from a flat pantograph and an overhead energized wire. Here, too, there is an exception in the diesel-electric LRT; the only example I for I can think of is the Camden, NJ to Trenton route. There is generally no interaction with freight.
“Heavy Rail” includes most freight and passenger lines (commuter and Amtrak). Sometimes the dominant idea was locomotive-hauling-coaches but that has never been the case all of the time (think of Edison cars, the old I.C. electrics and m.u’s that go back to the first couple of decades of the 20th Century). OTOH, some NJT lines seem to be going over from m.u. or self-propelled rail to locmotive-drawn (ALP-44’s and successors). Subways, Chicago’s “L” and rapid-transit systems like BART and its little brother, the Washington D.C. Metro, are also heavy-rail.
It is my understanding that what really separates the “light” from the “heavy” is the weight of rail used safely. It isn’t as simple as weight of the rolling stock, is it??
Generally “light rail” uses one-fare or zone fare systems and many of them are on the honor system; you might get a ticket if you’re ticketless on the light rail, but conductors do not go thru collecting tickets as they would on say, a commuter train.
To get an idea of modern light rail, try siemens.com. To get an idea of heavy-rail commuter, go
Definitions, not really dependent on weight of equipment or weight of rail.
Streetcar or trolley car. Loads from street, mostly on street in lanes shared with auto traffic, obeys regular traffic signals, usually operated by one man with on-board fare collections, usually operated as single car with possible one motor car and trailer or two-car mu operation, and a possibly a very small portion on private right-of-way and/or in tunnel or subway or on elevated structure. In addition to electric power, usually through trolley-wire, diesel or gasonline power and battery power are possible but very rare. Ditto horses!.
Light rail: Can load from street and/or from high and low platforms. Mostly on private right of way, with possibly some street running. May collect fares on-board, but usually prepaid with ticket machines, turnstiles or pass-gates. Rarely a single four-axle car. more often articulated cars with three or four trucks (bogies) and trains up to four cars usual when required. May obey traffic signals in a limited area, but usually has some type of signalling system, all the way up to cab signals and ATC. Subways and elevateds often found but not on most of a particular system. Diesel power possible.
Heavy Rail Rapid Transit All Private right of way, high car-floor level platforms, no street running, own signal system often state-of-art, subways and elevateds typical as well as surface running. Prepayment normal. Train operation typical and this involves end doors for crew passage between cars. Electric operation, third rail or overhead wire, universal for this mode.
Heavy Rail Commuter Rail All private right of way with few exceptions, fares proportiion to distances, some type of ticketing with penalties for use of cash onboard, high or low floor boarding, train operation normal, both self-propelled
also consider which is more likely, getting 40 passengers into a light rail vehicle or getting 2 passengers into an automobile mid day.
and watch your apples and oranges, there’s more to energy requirements than just inertia.
power source: rail possibly electric transmission via overhead wires; auto usually gasoline engine
friction: steel wheel on steel rail; rubber tire on asphalt
and potential control of starts and stops: rail may have control over traffic signals, dispatch and schedule can moderate confilicting vehicles; auto usually can only influence traffic via 1 finger salute and horn, often only after the conflicting vehicle has caused the stop, even on limited access highways