An orbital line for outer suburbs, well not many subway systems have them (the Madrid line Migeru mentioned may be counted one). The traffic demand is usually too light for a subway, so it should be for trams or buses (whose lack is not the subway system's fault). But the Purple Line from your and Wiki's description seems just such a project.
Moving my response over here, where train-talk fits a bit better....
Actually, in DC the subways and the buses are part of the same system. I know they're hoping that the new WMATA chief will work on the bus system, which really is a problem. I think he comes from LA, which has a lot more bus riders than DC.
And for some reason, a lot of people in DC don't like to ride the bus. It's kind of snobby; they think buses are for poor people. Also, the route system really is hard to understand, compared to the subway.
On a different issue, the DC Metro system doesn't actually serve DC's modern outer suburbs at all. The so-called "outer suburbs" were outer 20 or 30 years ago, but the whole area is so densely populated now, and housing prices in the inner suburbs and the city have risen so high, that they don't really qualify as "outer" anymore. The true "outer suburbs" can be upwards of 60 miles away. (My sister commutes to DC's inner suburbs by car from near the West Virginia border, around 85 miles or 136 km each way. I used to use a combination of bus and rail to get from a mid-to-outer suburb into the city; my commute was an hour and a half each way.)
And since the economic area is spread out as well (most of the jobs are in the suburbs, not necessarily the downtown area, which is largely federal agencies and related, e.g. lobbying, businesses) there are plenty of people who work in one suburb and live in a different one. They aren't really well-served by the Metro system as it stands. Actually, the entire transportation system (including the roads) is ridiculously overloaded, so nobody is really served as well as they should be.
For the far-flungs, light rail is obviously the answer, and it's being used to some extent, mostly on the Maryland side and in the far southern Virginia 'burbs. But people still remain inexplicably wedded to their cars...
As a radical lefty (and a student, which put me below poverty level except students are excluded from poverty statistics...) I insisted on riding the bus in Riverside, CA, and the bus there was definitely for poor people and (not necessarily poor) black/hispanic kids commuting to school. Barbara has a story of an old lady who got on a bus once and loudly apologised and said that she did not usually take the bus, that it was just this once because her son couldn't give her a ride.
I don't know whether it's snobbery, but how many Americans have never ridden on public transport? Those whom the Gods wish to destroy They first make mad. -- Euripides
not enough The world will end not with a Bang, but with a "do'oh"
On a different issue, the DC Metro system doesn't actually serve DC's modern outer suburbs at all. The so-called "outer suburbs" were outer 20 or 30 years ago, but the whole area is so densely populated now, and housing prices in the inner suburbs and the city have risen so high, that they don't really qualify as "outer" anymore.
You get a bit of that in NYC, but the subway network really is a lot better for getting around, and you do get a remarkable class cross section on public transport. A few years ago I'd gone to see a pre-auction viewing at Sotheby's. Those are rather strange - you've got normal schmucks like me treating it as a very nice free art exhibit, but there are also the actual buyers being sheperded around by obsequious employees (Six year old tugging at a woman's hand - grandma, grandma 'I've seen that one' - yes dear, it's similar to the one in the dining room', employee 'I can see he is quite precocious, one day he'll be a brilliant collector like his grandmother'). In any case I remember finding myself starring at a beautiful Cezanne with a distinguished looking elderly couple as an employee explained to them just how perfect that eight figure estimate painting would look in their bedroom and eavesdropping on the nice art-history discussion that accompanied the sales pitch. A couple hours later I was standing next to them waiting for the crosstown bus - they got off at Park, I didn't.
Well it's grown so fast that a lot of those not really outer anymore suburbs were just farmland back then - think Loudon county. Population: 1970 37k, 1980 58k, 1990 86k, 2000 170k, 2005 256k.
Rachael
