why two rails per track is practically better than one.

in my responses to kat_chan‘s interview question yesterday, tiff_seattle asked an excellent question and made some popular points to mass transit solutions in the Puget Sound: “Why do you not like the monorail? It goes just as fast as light rail and is way cheaper. In fact, since the entire system will be grade separated the line would actually be faster than light rail.”

well, here are six points worth mulling over.


1. light rail is faster to build. the 11.6-mile Hiawatha Light Rail Transit line, going from downtown Minneapolis-to-MSP airport-to-Bloomington’s Mall of America, is slated to take three years to construct. this included the boring of a mile-plus twin tunnel in 2002, customized highway overpasses and the building of completely new tracks. even though public service won’t occur until spring 2004, light-rail trains have already begun to test the tracks there.

also, the 18-mile TriMet Blue Line in Portland is 18 miles long and only took five years to build. Portland now operates three lines — one of those slated to open next year.

the Green Line Monorail, from West Seattle-to-downtown-to-Ballard, is roughly planned to be about 14 miles with no tunnels and over an existing bridge. were construction to begin right now, the opening date would be 2009.

Seattle doesn’t have the luxury to wait. see #6.

2. light rail transit technology can operate at both street level and in elevated capacity. unlike monorail technology, light rail tracks can be laid into existing streets without impeding traffic. the average light rail train is roughly three to four cars long and can cross an intersection in about fifteen seconds or less. this can be timed with traffic lights in most cases.

this is advantageous because the right-of-ways for building a track on an existing wide street can still allow for automobile traffic on that street (usually reduced to one or two lanes, depending on its original one- or two-way intent, respectively).

take TriMet’s MAX service in Portland, for instance. because light rail tracks can be inset into a street (in this case, the Blue Line on Burnside Avenue in Portland/Gresham comes to mind), automobiles can cross the rail-enabled intersection without any problems (you don’t even notice it). this usually has minimal to no impact on cross-street traffic, and it permits pedestrians to access the services quicker and with less hassle of climbing or lifting to an elevated platform which also mars the cityscape in ways a ground-level line wouldn’t.

further, in places where no existing right-of-way roads exist for MAX’s Blue Line, the elevated technology works seamlessly.

because of monorail’s track structure, inlaid-flush street-level crossings are not possible. that proponents of monorail technology sell the point that monorail is “immune” to city traffic is a red herring on this point, because light rail can both exist on streets and do so without apparent traffic impediment.

3. the cost of maintaining light rail transit is lower. because light rail technology borrows heavily on existing dual-rail technology — a venerable format used since the 19th century — the cost of upkeep is lower. more mass transit systems globally (and especially in North America) use this technology, and the availability of parts and vendors is more plentiful. plus, the technology has proven itself to be reliable. further, track right-of-way, with special agreement, can be shared by other transit systems as the needs require, such as existing trolley service and the like.

4. monorail technology hates curves. it’s true. that’s the biggest contention facing monorail planning. the Green line tries to minimize the number of times it has to change direction, because monorail parts wear out quicker from changes in direction, resulting in more maintenance and higher long-term costs. local communities vying for access in their neighbourhood to the proposed Green Line have rendered the track options to be riddled with curves galore, which would spell misery for the upkeep of that track.

5. light rail is cheaper to build. case in point: the Hiawatha LRT in Minneapolis, at 11.6mi (plus the boring of two 1.2mi tunnels, one for each direction), runs at a cost of $674 million, most of that covered by the Federal government under its transportation initiatives. this is money that Minnesotans will not have to pay back. the Seattle Monorail green line, in comparison, at 14mi, is projected to cost $1.255 billion — pretty much double in cost, using today’s dollars. and much of that will be paid by a motor vehicle tax.

in Houston’s METRORail FAQ for the 7.5mi initial line currently being built from downtown-to-Medical Centre-to-Reliant Field/Astrodome complex (opening in 2004), question #6 addressed the monorail cost and maintenance option, which cites it as being prohibitively expensive (at least $1.3 billion — or more — for building monorail versus $324 million for building light rail).

Houston is interesting to note because it shares a lot in common with Seattle’s road pollution and automobile congestion problems — more so, perhaps, than the examples cited in Minneapolis, Portland or elsewhere.

also, it’s important to note that Houston’s inaugural METRORail project is slated to take three years to build.

6. Seattle doesn’t have the luxury to wait. it’s very understandable why Seattleites would be all for monorail technology. it ties into a local patriotism which reaches back over forty years and makes Seattle distinctively unique in contrast to other newer American cities. proponents also contend that monorail trains can travel faster than light rail trains.

but the technology, while impressive in itself, hasn’t taken off in several transit regions for the very reasons listed above. historically, the Puget Sound has flirted with several mass transit solutions, all to questionable or failed ends.

mass transit technology should have occurred in the area no later than 1993, but even now, car-dependent Puget Sound can do nothing to control its growth, unimpeded by how far one can drive. it’s not unheard of for people to drive into the city to their workplace from places as remote as Enumclaw, Cle Elum, Bellingham and Centralia. in some cases, this is well over 75 miles from downtown Seattle. in Minnesota terms, it’d be like driving from Albany, Eau Claire, New Ulm or even Willmar to Minneapolis for the same. in Portland, that’d be like driving from Hood River every day.

further, speed is not a primary consideration when navigating within the city limits. rather, reliability is. it doesn’t matter how fast a multi-stop train operates if all it’s doing is saving a minute or two with a rail line containing 5-minute rush-hour intervals anyway. you can get there from here in a minute or two slower on a more reliable technology like light rail, whereas the only option now is to be up to an hour late while being stuck in I-5 or Aurora/Alaskan Viaduct/99 traffic.

so, like, that’s what i’ve gotta say about the matter. i’d like to hear some comments.

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