Metro green-lights study of Powell/Division corridor, hints at broader BRT future.

At it’s recent Thursday meeting, the Metro board voted 7-0 to move forward with a study of the Powell/Division Transit Corridor. The corridor in question stretches from Portland State University out to Gresham, centered on SE Powell Boulevard and SE Division Street, ending around Mount Hood Community College. Screenshot from 2012-05-18 23:48:54.png

(A full-size pdf of the above map is here).

As widely expected, Metro planners envision the corridor to be some sort of Bus Rapid Transit, not light rail. In a bit of a surprise, Metro planner Elissa Gertler suggested that this might be a way of doing business that the region embraces more in the future. In an interview with Metro staff reporter Nick Christensen, she said “”We are focusing on lean and mean solutions. Whether it’s the Southwest Corridor or any other corridor, we have a different definition of success. Every corridor plan does not necessarily have to end in a giant EIS (environmental study) for light rail. Most corridor plans are not going to end that way for a long time.”

While I would be surprised if the Southwest Corridor wasn’t another light rail line–there are many reasons it too could work as BRT, especially if the money (or political stomach) isn’t there for future light rail expansion. Much political capital has been spent on Milwaukie MAX, as well as financial capital; given the uncertainty of funding for large capital projects going forward, BRT can be an excellent way to improve transit service without breaking the bank.

43 responses to “Metro green-lights study of Powell/Division corridor, hints at broader BRT future.”

  1. It would be interesting to give BRT a try, but if Hales wins the mayoral election I suspect we can see a push in a different direction.

  2. If done right, a Powell/Division BRT could be great. If not, the project could do for advanced bus transportation what GM did for diesel cars 35 years ago. It looks like we’re going to be closer to the latter.

    The impetus for BRT within government circles seems to be that it would be cheaper than LR. The rationale should be that, for a given project, it would have better results overall. If we’re not prepared to put in as much money into it as we would a rail project, we’re going end up with a 2nd rate system.

    The choice of where to have the region’s first real BRT is critical, too. Imagine if our first rail project was WES, the first MAX the Yellow line, or the first streetcar just from OMSI to the Rose Quarter.

    We need to go for platinum on the first BRT: a multi-line open system with grade separation. Otherwise, bus transit will always be seen as something less than rail.

  3. I don’t see how we can realistically do grade separation (or dedicated lanes, for that matter) over the entire length of the project. I expect this would have to be more of a BRT/BRT-lite hybrid like EmX in Eugene: some dedicated lanes, some mixed lanes. It doesn’t need to perform quite as well as light rail; it will be sufficient to get maybe 50% – 60% of the benefits for 5%-10% of the capital cost.

    Tri-Met should also consider trolley buses with off-wire capacity for BRT service. It’ll cost more up-front to install the overhead wire, but there may be savings over the long run. I understand electric buses have a much longer service life, and we can’t rely on gas prices coming down and staying down in the future.

  4. It’s not a matter of grade separation over the entire length. Consider the original east side Blue line. The line enjoys grade separation in Sullivan’s Gulch but not east of 205 or, except for the Burnside Bridge underpass, in downtown. But that section along 84 makes quite a difference and did not stop the freeway builders from improving the Banfield.

    What I’m saying is that we should approach the first BRT project with a question like “If it would cost us X dollars for LR, how good of a BRT could we have for the same money?” If we go in saying that we can’t afford the real thing then we’ll end up with an inferior project. That might be ok for the 3rd or 4th BRT project, but the first ones need to show that BRT really can be better than LR for the same investment.

  5. Fair enough, but where could it be grade separated? Grade separation on MAX has used either a freeway shoulder, an abandoned rail right-of-way, or a tunnel — and I don’t see any of those, or the opportunity for any of those, anywhere in the study area.

  6. YAY for bus rapid transit (finally!) along Powell. That said, there is no space for a dedicated ROW along Powell for either LRT or BRT. Thus, it will have to be some kind of BRT light, hopefully with signal pre-emption.

    Of course, Trimet will probably stick with 40-foot buses, instead of more appropriate 60-foot articulateds with 3 and 2 seating.

  7. the first ones need to show that BRT really can be better than LR for the same investment

    I’d say it has to be shown it can be cost-effective. Unless a corridor is well-suited to taking advantage of BRT’s unique advantages, at the high ends of project scope (i.e. full busways), the cost differences between bus and rail disappear, and rail becomes more cost-effective in many cases.

    The key advantages of BRT over similarily-priced rail are:

    * For lower-end BRT, there’s no such thing as similarly priced rail. Of course, what we condier “low end BRT” (something like LA’s Metro Rapid services) is standard service in much of the rest of the world.

    * Medium quality (“class B”) BRT can be done likewise cheaply, if you are willing to take lanes from cars. East of I-205, SE Division has five lanes of traffic FTMP with on-street parking; were the region to take away the parking lanes (or take away two driving lanes), a very high-quality BRT service could result.

    * BRT can be staged much more easily, as the vehicles can operate (in most cases) as ordinary bus service on standard local streets. Right now, one can’t take a train to Vancouver, as the tracks doesn’t cross the Columbia, and trains can’t use the Interstate Bridge. You can get as far as Delta Park, but then you need to transfer to a bus. Were a BRT line built out to I-205 and no further; you still would be able to ride to Gresham–the latter half of the trip would just be on local streets, like the 4 and 9 are now.

    * BRT can avoid expensive construction around difficult areas. Widening the Powell undercrossing of the UPRR mainline, or otherwise providing a dedicated transit corridor here, would cost a lot of money. With LRT, you’d have no choice. With BRT, you can run the busses through the existing tunnel for this stretch.

    * “Open BRT” is well-suited to areas where transit has a branching topology. This doesn’t apply to Powell/Division, where an effective grid is in place (or was in place before 2009); it does apply, however, to the Southwest Corridor.

    I don’t think that a Powell/Division line needs to be competitive, in some sense, with the Blue Line. This is a transit corridor with around 17000 trips per day, already. If it can improve service reliability and speed along the corner (and if these savings can be turned into frequency improvements), it would be a win.

  8. That’s the point.

    Maybe it will become just a matter of nomenclature. If we end up with anything other than a high-standard true BRT for Powell/Division we should just call it “enhanced bus” or something, leaving the hope that BRT could be offered on another project.

    I still think that the SW Corridor offers a fantastic opportunity for BRT if we’d be willing to spend LR-like money on it. How can that happen if people see bus services as necessarily being second rate?

  9. I don’t anticipate that Tigard is going to settle for an “enhanced bus” system. They tried that in Milwaukie after South/North failed and the city ultimately balked. Tigard has much more clout (population, employment, retail, tax base) than Milwaukie and arguably a much greater need for MAX service. Of course BRT will be studied as an option, but count on MAX being the LPA for Southwest.

  10. That’s a good point about Division east of 205. West of 205, Powell has grassy medians and wide grassy curb strips that could be removed to make way for bus lanes all the way to 50th. (That means losing a lot of street trees, so there WILL be opposition). But at least there’s the potential to create a dedicated busway from 50th to Gresham, and to share the MAX right-of-way (and stations) from 17th and Powell all the way to the transit mall.

    So potentially, a Powell/205/Division BRT line could be built with as little as two miles of shared roadway on Powell, and perhaps with only two stations along that segment … say, 28th and 39th.

  11. This is great news. Recently I’ve been thinking that certain corridors are ideal for BRT, and Powell would be at the top of that list (among other reasons, it makes sense politically since Gresham is already served by LRT).

    Although grade seperation would probably be infeasible (not to mention cost-prohibitive) for much of the route, I could see it being strongly desirable in a couple of segments, namely the notorious intersection of 82nd and Powell (such locations can be served by elevated stations).

    Another corridor that could hold BRT promise, and I believe this has been mentioned in a couple of studies, is Columbia Blvd. roughly between St. Johns and Parkrose. As Aaron points out, LRT will probably the mode of choice for the SW Corridor, especially since it’ll (ideally) be serving major destinations like OHSU.

  12. I just wonder where there is room for a BRT/LRT dedicated right-of-way along 99W in the Southwest Corridor. Doesn’t seem so to me.

  13. I think budget is really going to dictate what we get here. If the budget is tight, we will see a BRT-lite, with signal queues, a few dedicated spots, etc. If money is available, we will see a max line. The connection on the west end is very simple, and the east end provides the opportunity to connect easily with the Ruby yard.

  14. My years of BRT experience at Lane Transit District in Eugene have taught me one thing: BRT is way less sexy and far more controversial than light rail.

    That’s all. Not saying we shouldn’t do it or it wouldn’t be good. But it will be a battle on all fronts from start to finish, and even heavy transit advocates may fight against it (because it isn’t light rail, as was the case in Eugene for a long time).

    Oh, and one last thought. If TriMet can’t handle making the MAX rapid, I somehow doubt this will be bus “rapid” transit. R A Fontes said “Enhanced Bus” which seems more accurate to me. BRT is notorious for not being done correctly in the US.

  15. Nick,

    I know the proposed W. 11th extension of EmX is quite controversial, particularly coming on the heels of the cancellation of the equally-controversial West Eugene Parkway, but how much controversy surrounded the original Eugene-Springfield line and the Gateway extension?

  16. The Community Transit (Everett, WA) express service to Seattle cost $23 million for 23 90 passenger double decker buses. However, they are also making use of stations that were built for their SWIFT system. But on somewhere like SE Powell Bv. knocking the tree branches off could be a major problem for those tall buses.

  17. I support BRT on Powell (and on Division as well, in the future), because it will allow buses to run thru without a transfer, and can cheaply repurpose existing road space if done right.

    But I don’t understand the comment above which claims “there is no space for a dedicated ROW along Powell for either LRT or BRT.” This is untrue, and I’ve addressed it before, even making this map: There is currently 2 lanes in each direction all the way from the river to 205, and most of that stretch also has a center turn lane. The total street width is almost always over 100 feet, building-to-building, and the roadway and median width (curb-to-curb, not sidewalk) is 56 feet or more; at least 5 lanes. East of 205, the roadway narrows, but the street right-of-way is usually at least 80 feet, and mostly over 100 feet, so the roadway could be widened to match.

    56 feet is enough room for 2 standard car lanes (10 feet each), 2 BRT lanes (12 feet each), and 12 foot wide platforms at stations, plus left turn lanes when there is not a station. It might even be possible to fit in some 5 foot bike lanes on each side, if the lanes were made a little narrower, though it would be a tight fit at stations.

    This line needs to have an exclusive right-of-way for buses the whole way to 205 (and all the way to Gresham in the future, if Powell is widened), if it can be called BRT.

  18. I’m surprised the map leaves off Reed College, which is barely off the radar somehow even though it’s near the new MAX and just a few blocks from the area that this is projected to impact.

    Also, I’m pretty sure Powell has some excess ROW for parts of its length (including frontage parking lots) from the planned Mt Hood Freeway having ODOT acquired land there. It may be possible to build a higher speed MAX line with some over/underpasses, and some at-grade crossings along the route depending on ROW and neighborhood support.

    I would think the Green Line would be enhanced by having service from CTC through Powell as well, so maybe it’s not just a pipe dream.

  19. Reed College is over a mile away from Powell Blvd, so it’s not surprising at all that it’s not shown as part of the Powell corridor. It is, however, about a 1/4 mile from the Milwaukie MAX and there’s a “future” station at Harold that would serve the campus very well.

    I AM surprised that the college isn’t making more of a fuss about deferring their station to a later date. There are tons of ultra-liberal, environmentally conscious students and faculty who would make great use of the Harold station.

  20. One thing I have noticed when people compare the cost of buses vs light rail: they never include the increased wear & tear on the streets. Light rail costs a lot because you have to put the rails in, obviously, but once that’s done they last for a very long time. Over the same time and for an equal ridership, how much damage do buses do to the roadways? Are there any numbers out there concerning this?

  21. Joseph: There’s easily room for dedicated transit lanes on Powell if you knock out a traffic lane each way. However, Powell is a state highway that carries a lot of traffic. I don’t see the state giving up half the automobile capacity of a street that busy. Give up street parking lane or bike lanes, sure… but I suspect any less than two traffic lanes each way from the Ross Island Bridge to I-205 will be a deal-breaker. Given those probable constraints, I think you’d need a minimum of 65 feet from curb to curb (75 at major intersections) to pull off true BRT on Powell.

    Aaron: Reed College is a residential campus, not a commuter campus. While I don’t doubt the students would use the MAX to get into town for fun on occasion, they don’t need it on a daily or even a weekly basis; everything they need and most of what they want is walking distance from their dorms. The Harold Station wouldn’t generate ridership, which is why it was deferred. A MAX station would be a nice perk for Reed, but it’s hardly a high priority for anything they do.

  22. A station at Harold would likely require improved E/W access to be beneficial, including a better way to cross 99E to the west, and a way (currently there’s none) to cross the tracks to the east.

  23. Yeah, a very nearly essential component of a Harold Station would be a Reedway pedestrian/bike bridge.

  24. Of course a bridge would be necessary, and costly, which is probably why it was deferred. But I disagree that Harold station wouldn’t generate ridership.

    Students aren’t sequestered to campus, they need to get out for shopping, socializing, cultural activities, etc. And the students may live there, but the staff and faculty still have to commute every day. So there would absolutely be a lot of ridership generated there. Also being connected directly to PSU and OHSU can only be a positive.

  25. I live near 60th between Woodstock and Holgate, so Powell and Division are not my main bus services, but they are handy from time to time.

    Do we really need the 4 and the 9 to move faster? Not really, but we do need higher capacity on those routes.

    Do we therefore need larger busses? Again, no, but we do need more busses running at shorter intervals.

    The 4, in particular, always is jammed during the day. Decreasing interval would both increase capacity and reduce trip time, for one’s waiting time would be shorter. This line could and should run at half its present interval; it then would be more convenient and pleasant, as well as quicker for its patrons.

    BRT on Powell and Division exemplifies the mode fixation that Jarrett Walker has warned us about: a preferred solution looking for a problem.

  26. “One thing I have noticed when people compare the cost of buses vs light rail: they never include the increased wear & tear on the streets. Light rail costs a lot because you have to put the rails in, obviously, but once that’s done they last for a very long time. Over the same time and for an equal ridership, how much damage do buses do to the roadways? Are there any numbers out there concerning this?”

    It would probably depend upon how many other heavy vehicles are using the road. I don’t think a bus running every half hour or fifteen minutes is going to do that much. They may also become lighter in the next generations of vehicles, especially if alternative power is used. But you would also want to look at the long term costs of the passenger facilities along a BRT route as compared to those on a dedicated LRT line. Lots of factors in economic calculations: Borrowing costs, potential adverse litigation in property acquisition, portion of damage attributable to the BRT vehicle, maintenance of passenger facilities, safety costs, time investment by the community in planning, readiness to implement service. Even where there was already a path for LRT, such as along the I-205, it still had a lot of engineering difficulties which a road established for multiple uses doesn’t.

  27. This will be a very important project to get right, since it will form opinions about BRT in general.

    I agree with others that there is really no way to do Class A BRT for most of this corridor–the right-of-way is just not wide enough. We can get Class B BRT for most of the line, though. Division east of 205 is very wide and can fit bus-only lanes. Powell east of 50th has a median that can and should be removed (trees in the middle of highways are very over-rated–keep them on boulevards and main streets). It also has those weird frontage parking areas that could be used to widen the road or make space for stations.

    The stretch from 50th to 17th will be Class C (mixed traffic) or perhaps B- (BAT lanes or peak-only lanes), but can still be enhanced by wider station spacing, off-board payment, and signal priority.

    From 17th to downtown it could be a mix of Class B (a dedicated lane running alongside the light rail tracks) and Class A (the new bridge).

    We need to stop thinking in terms of “BRT” and “BRT-lite” and “Enhanced Bus” as if they are these fixed systems. In reality any bus or rail system can mix different classes of service. Seattle’s RapidRide is still BRT, but it is a mix of Class C and Class B service. People can be upset about that, but it’s unhelpful to say “that’s not real BRT” or “that’s just enhanced bus.” Nobody says MAX is not “really LRT” just because it is class B for much of the system. We just have to be clear about the various levels.

    One major advantage of a busway is the possibility of an open system. Even with the grid system, I think this would be a great place to use an open system combining several lines. Several of the routes in East Portland and Gresham that run through low-density areas could come together on the busway. The idea, for example, is to have 3 routes at 30-minute frequency going through less-dense areas combine to provide 10-minute frequency on the main trunk line. Seattle has a great set of routes (71, 72, and 73) that do this. This type of system is arguably better than the current common practice of running infrequent feeders to frequent MAX service. The downside is that an open system is a bit harder to brand, but it could be done by giving each bus a letter or just labeling them with their ultimate destinations. Most people will just use the shared portion anyway. I will admit that with enough north-south service in East Portland this scheme would not be as necessary.

    Someone above made a comment about articulated buses. It is actually better to run 40-foot buses more frequently rather than pay more for 60-foot buses that run less frequently. Think about how much frequency you can buy with the extra costs of buying 60-foot buses. The only reason to use articulated buses is if frequency can’t be increased, like if you are at 3-5 minute headways and crowding is still happening. I don’t see that happening anytime soon. They should probably build 60-foot platforms just to future-proof it though.

    I think SW corridor may have to be BRT, whatever Tigard wants. Light Rail is kind of pointless without a tunnel under OHSU, and who is going to pay for that? Once we decide to go with Barbur, it makes more sense to go with BRT, which again could be a mix of Class B and C and could be an even better corridor for an open system since everything is funneled to downtown through there. Many cities could be served with one enhanced system. It is also easier to justify removing some car capacity (or at least priority) on Barbur considering it parallels I-5. I know both are congested, but this amounts to a ridiculous amount of car capacity in one narrow corridor.

  28. JimLee, I disagree that they are being overly mode-centric. What Jarrett Walker criticizes are things like the Portland Streetcar Plan, which chose the mode first and then asked “where can we put them?” In this case, Powell-Division was one of many corridors studied a couple years ago in the Metro High Capacity Transit System Plan. These corridors were studied in a mode-neutral manner, and looked at density, destinations, land use patterns, etc. Only after being studied were they recommended (or not) for specific rapid transit systems. The plan identified several corridors as being more appropriate for light rail, and identified others as being better served by BRT. Powell-Division was recommended for BRT due to lack of ROW and too little demand to justify the high cost of a tunnel.

    Regarding the wear on the roads, I’ve noticed Seattle and Portland have both started paving heavily used bus stops using concrete. This BRT Line would be a good excuse to pave the bus lanes or station stops with concrete to prevent wear. In the future, the city should consider paving all bus routes (and freight routes) with concrete. Asphalt is not worth the lower initial cost if it requires constant maintenance. Of course, it would not be fair for TriMet to pay the full cost of this, since other drivers would benefit as well. It should be a partnership with the city.

  29. “Once we decide to go with Barbur, it makes more sense to go with BRT, which again could be a mix of Class B and C and could be an even better corridor for an open system since everything is funneled to downtown through there. Many cities could be served with one enhanced system. It is also easier to justify removing some car capacity (or at least priority) on Barbur considering it parallels I-5.”

    Zef, how about using a BRT express service picking up passengers in Sherwood, then Tualatin, then getting on the I-5? This would serve two communities, and also avoid the very slow 99W corridor. There already is an uncongested highway between the two, and then Tualatin is adjacent to I-5. Perhaps something could be done to facilitate the buses on I-5.

    Tigard is close enough that alternatives and bus service on Barbur can still work well. That leaves out King City, so I guess an extension from Tigard would be needed.

  30. I share Aaron Hall’s concerns about pavement damage, especially after transit agency’s exemption from state and federal fuel taxes is factored in.

    Even so, the bias on the part of federal, state, and local governments to provide easy funding for capital projects as opposed to ops is a much bigger concern. Then the ability of transit operators to totally disregard capital costs in their operating reports is just too much. In the real world, capital expenditures (excepting land) are depreciated over equipment lifetimes, with the depreciation carried as an expense.

  31. Even so, the bias on the part of federal, state, and local governments to provide easy funding for capital projects as opposed to ops is a much bigger concern.

    ~~~>This really is the issue and for some unknown reason it’s never brought up.

    It’s like mass blindness syndrome. Nobody wants to see the truth so they just keep on plodding away with what DOES NOT work, which is the American model of mass transit.

    Keep building but keep cutting.

    It’s Kafkaesque.

  32. Ron, I do find it curious that Portland is so resistant to such radical ideas as HOV lanes and express buses. It would work very well in serving specific commuter markets like the ones you mention. Sherwood is far enough away from downtown Portland that few people are probably willing to ride a local or even a rapid all the way, so express would be more popular. I wouldn’t call that “express BRT” though. Rapid and Express are two different types of service.

    That said, most commutes these days are suburb-to-suburb or city-to-suburb, plus most trips are not commutes, so we also need local service, and rapid service where there is enough density to warrant it. Rapid service should probably stop at Tigard, with less-frequent locals connecting from outer suburbs. Alternatively, with the open BRT system, local buses in the outer suburbs can combine into one very frequent service. I would love to see the 54/56 corridor get BRT treatment in addition to the 12 corridor, with both accommodating multiple lines.

  33. “I think SW corridor may have to be BRT, whatever Tigard wants. Light Rail is kind of pointless without a tunnel under OHSU, and who is going to pay for that? Once we decide to go with Barbur, it makes more sense to go with BRT….”

    zef, I think the tunnel under OHSU is going to be a necessity, so light rail is far from pointless. In fact, I would bet that doing BRT on Barbur from downtown to beyond Terwilliger is going to be MORE EXPENSIVE than tunneling under the hill. Remember, Barbur is essentially a viaduct for most of that length, anchored precariously to the side of a very steep hill. So widening Barbur to accommodate ANY transit line (BRT or LRT) will be horrendously and prohibitively expensive. Tunneling may end up being the LEAST costly option for getting beyond Terwilliger.

    Regarding Powell, I also don’t understand why everyone thinks the ROW is too narrow to accommodate exclusive BRT (or LRT) lanes. Joseph E brought it up earlier and he’s exactly right, there’s plenty of room within Powell’s existing ROW along all but a few blocks of its entire length from SE 17th to Gresham. It gets a little tight from 20th to 22nd, and again from 26th to 29th, but the rest of the way is smooth sailing.

  34. Right, I under stand the difference between express and BRT. That said, I’m curious as to how Community Transit in Everett is doing with their express service. I was thinking Sherwood and Tualatin could be combined for something similar. And Comm. Transit apparently is so cost minded they haven’t done any reports, so it’s hard to know how well received it has been. I’ve seen only a couple of videos surface from riders. They did have 90% of the cost of their new buses covered by grants, so it was a pretty good deal.

  35. Ron, are you talking about Swift? That is not an express service either, that is a class B/C flavor of BRT. It has BAT lanes (shared with right-turning cars) for about half its length, then is in mixed traffic the rest of the time. It only stops about every mile, so it goes pretty fast, but it’s not express because it doesn’t go non-stop for any portion. It stops automatically at every stop like light rail does. As far as I know it doesn’t get a lot of ridership right now, but that’s because the land use is extremely car-oriented. There are lots of plans to retrofit and densify around the stations.

    Aaron, I appreciate the value of a tunnel under OHSU, but I have strong doubts about the political appetite to spend another couple billion dollars mostly to serve one institution. The relatively low density and demand in the rest of the SW corridor would never justify the cost of a tunnel, so it will be a tunnel that primarily benefits OHSU. Unless they are willing to pay for a big chunk of it, that seems like a difficult sell to the public. I don’t understand the contention about Barbur. Why add capacity? A Class C (mixed-traffic) BRT would be a huge improvement over existing service, and at key points they could build things like queue jumps or bus-only segments to get around bottlenecks.

    Again, the SW corridor is not a high-density corridor anyway, so incremental improvements are more cost-effective than spending massive amounts on a poorly-performing underground rail line. We are not New York City or Washington, DC, or even Seattle. We should not be building underground rail until we are serious about building dense urban centers.

  36. Ah, that makes sense. Yeah, I really like the doubletalls. Haven’t gotten a chance to ride one but it’s fun to see them going through downtown Seattle. That’s not really a special service though, they just took a couple existing express services and substituted double-decker buses to deal with capacity issues. By going with double-deckers, they can get more capacity without taking away parking to make room for articulated buses. Pretty clever! While locals and rapids are better off running small buses more frequently, express services often benefit from increased capacity since you end up with a lot of people who just want to get from point A to point B and who are willing to follow a schedule.

  37. I think one issue with the D-T’s are tree branches (someone put up a video of one hitting some in Seattle) but hen they stay on a well traveled route, which they must do anyway, that is not so much an issue. Some people are concerned with the upper level being out of sight of the operator but they may have devised a way to deal with that. These buses have a traction capability that adjusts to slippery conditions and performed well during the last winter, whereas articulated buses can have a lot of trouble.

    Still would like to see some financial reports from Comm. Transit. Alexander Dennis stopped in at Tri Met with one of their buses while delivering them to Everett in 2011.

  38. In an earlier life I learned the basic theory of transportation by studying high-rise office buildings, in which the design of elevators is critical and determinative. A building can choke on its transportation system.

    An architect has the advantage of designing not only the system itself, but also of configuring destinations to be served, a luxury that urban planners and transportation engineers must envy. In a sense elevator systems are the terminal capillaries of surface systems, for without them hyper-dense urbanizations would not be possible.

    As with surface systems, the basic technologies of vertical systems are more than a century old, but continually have been improved, especially those controlling assignment of service. Nowadays one does not just punch an “up” or “down” button, but enters one’s destination–the number of the floor. An optimal adaptive control algorithm then chooses the car best suited to the service required and sends it to proper floor for pickup, then on to the passenger’s destination: a complex exercise in queueing theory, a transportation app which surely must intrigue Mr. Chris Smith.

    However, one only need work a few fundamental problems in standard third year texts for students of architecture to be convinced of some basic facts:

    Speed of car is the least important property.

    Capacity of car is the next least important property.

    Configuration of system is the most important property.

    Tall buildings must be divided into zones of floors, with express service to upper zones.

    Express service bypassing lower zones does benefit from higher speed.

    The goal is to provide short service intervals and dependable trip times.

    Sound familiar?

    A note on nomenclature: “interval” is time between services; “frequency” is number of services in a unit of time. One is the inverse of the other: 10 minute interval is a frequency of 6 per hour; 20 minute interval is a frequency of 3 per hour, and so forth.

  39. Keep in mind, Jim, that the stop penalty for an elevator is much, MUCH greater than the stop penalty for a transit line. If a bus stopped (or could stop) every block, that would be more analogous to how an elevator in a high-rise operates. (And some local-service lines do operate like this).

    Reasonable transit lines–even local-service ones–have much greater distance between floors. Imagine a building where elevators only stopped every fifth floor, and building users were then asked to walk up or down up to two flights of stairs to reach the floor they wanted. (Ignoring the ADA issues with such an approach).

    The elevator example is instructive and useful, but several of the parameters differ.

  40. An tunnel under OHSU not only serves that institution. It also serves the VA. In addition, it serves the community as a whole, in that anyone needing medical care from any of the providers on Marquam Hill will have a way of getting there even when the weather is bad and the roads are completely iced up or blocked by landslide.

  41. Here’s a wild idea, just for the sake of discussion: What about moving the green line to this corridor? What would be the implications of that?

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