How large does a Metro area need to be to support Light/Heavy Rail?

[nowyano]

How big do you think a metro needs to be to have a succesful light or heavy rail system? I know there are some examples of small cities (Margantown, WV?) with light rail, and it's metro population is only around 150,000 I don't really know the size of other country Metro regions but most of the known systems in the US (NYC Subway, MBTA, DC Metro, SEPTA) are all along the east coast in dense areas of more than 1,000,000 with their metros. I am just wondering how large people think a metro area needs to be to support a system.

[monsoon]

I think you need two things. First there needs to be the density that would justify the building of a LRT or HRT. Second, you need a city large enough to financially support the construction and operation of the system.

Due to the enormous cost, I don't think there are any cities in the USA that will be starting a HRT that doesn't already have an HRT. Part of that is because most of the growing cities are not growing in a manner where a HRT is justified. The last new HRT in this country, the Los Angeles Red Line, has not been a big success and as a result the metro has moved on to LRT and BRT. (Bus)

Based on the size of the cities that are putting together LRT lines I would say the minimum sized metro that could handle a LRT would be 1.5 million and this if most of the metro is concentrated in the core of the metro.

[dtown]

Id say 1 million with a fairly dense core. I cant think of any examples for sure, but if Tacoma can do it, a lot of other can too.(Im pretty sure Tacoma is in the Seattle Metro, so it will have a huge metro population.

[tampasteve]

I believe that a core pop of around 1 million is a good number to start at for HRT. LRT is great, but when you need to move a LOT of people fast, you need a larger system like HRT. I would not be surprised if cities such as Houston, Dallas, and other large cities start to plan HRT lines in the next 50 years, to be operational in 60-75 years from now. I would like to see the metro planning for large cities to see if they are planning HRT for their 30 or 50 year plans.

[lammius]

An area's population cannot be any basis for determining whether or not fixed guideway transit systems are appropriate for a given area. It all has to do with the 4-step process of transportation modeling. If there is enough travel demand between certain points, and there is such a time or dollar cost to alternative travel modes (i.e. driving), then there is likely a transit market worth serving. There are instances in which a single light rail line makes perfect sense for a small town of 50,000, but is not suitable for a portion of a metro area of 2 million

[tamias6]

I'd say one needs atleast a mid sized city with a dense core and geographic and / or legal obsticals that discourages sprawl.