The whys and wherefores of MAX bus bridges


In the previous post, we lamented the recent spate of (sometimes bizarre) incidents affecting MAX service, in particular a car which ran off a freeway offramp and landed in the middle of Sunset Transit Center, shutting down MAX service on the westside for the better part of a day. (Nobody was badly hurt; the driver was arrested for DUI).

The topic swiftly turned to the contingency plans TriMet deploys whenever there is a major outage on the rail system–the bus bridge. A bus bridge consists of a fleet of busses transporting passengers between two out-of-service segments on the line. Nobody likes it–it is inconvenient for rail passengers, who have their trip times lengthened considerably (but certainly preferable to being stuck). It is inconvenient for bus passengers, who often see runs cancelled due to the need to service the bus bridge, and it is expensive for TriMet, who may have to pay operators overtime due to the unplanned additional service need, as well as pay for lots of unplanned deadheading.

And some bus riders claim that the practice is unfair to them–that bridging MAX, Streetcar, or WES is a rail problem, and thus ought not have any adverse affects on bus riders.

The mechanics of a bus bridge

A bus bridge occurs when a section of track goes out of service for an extended period of time. This may be due to a broken-down train, a collision, a problem with the tracks, signalling, or power lines, or any number of other reasons. Short outages generally don’t produce bus bridges–and in some cases there can be an aggravatingly long wait before a bridge is ordered (if it is a mechanical problem for instance, TriMet may try to fix it on site before taking the line out of service–which requires a mechanic travel to the problem, troubleshoot it, and decide if it can be fixed easily or not; meanwhile, trains back up upstream of the incident).

If a bridge is ordered, the section of track taken out of service extends to the nearest turnaround points on either side. There’s a limited number of places on the MAX line where trains can reverse direction–generally, at transit centers with pocket tracks (such as Beaverton, Rose Quarter, or Gateway); as well as the Blue Line turnaround near Galleria downtown, and at the ends of lines. Most of the MAX system (outside these places) is signalled in only one direction; and MAX trains are forbidden to travel backwards (against the signals) under normal operations (and certainly not with passengers on board). Thus even if only one half of the line is affected (such as by a broken-down train), the bus bridge is bidirectional; trains cannot pass the broken-down train on the opposite track, and a balance of trains on both sides needs to be maintained.

Thus, when a bridge occurs, trains will enter the pocket track or turnaround at one of the stations at the end of the outage, unload passengers, pick up passengers heading the other way, and then leave in the opposite direction. Busses then transport passengers to the station at the other end of the out-of-service section, serving intermediate stations. Depending on the situation, busses may also pick up passengers from trains stuck in the closed section (though passengers on a train involved in an incident may have to wait, particularly if the train is stopped in a place where safe unloading is not possible).

To do a bus bridge, you need two things: 1) busses, and 2) bus drivers. #2 is often the harder resource to come by–TriMet keeps a number of busses in reserve, even at peak times, and at off-peak times (when MAX loads and frequency are lower, and fewer busses are needed) there are even more unused vehicles available. TriMet doesn’t, however, like to pay drivers to sit around waiting for the phone to ring, so when a bus bridge occurs, drivers can come from one of several places:

  1. Supervisors and mechanics still current on bus training and licensure, and thus legally able to operate a bus
  2. Busses (and drivers) deadheading at the end of a run
  3. Off-duty drivers who agree to be called in
  4. Drivers diverted from operational bus service

MAX operators are generally not available for a bus bridge–many may not have current training or licensing, and trains cannot be abandoned along the line.

In many cases, there are not enough of numbers 1-3 to go around, so bus bridges are staffed, at least partially, with #4. Generally, busses and drivers are only taken out of regular service at the end of runs, as terminating a run mid-route and booting off the passengers would be rather rude–but if it is a bus you are expecting that is taken out of service, and the line is not a frequent one (or is frequently crowded), you won’t be a happy camper.

Needless to say, bus bridges can be highly disruptive to scheduled bus service.

The equity issues

Some TriMet riders, particularly those who mainly use the bus system, consider this situation inequitable–questioning whether or not it is fair to disadvantage bus riders for the benefit of rail riders. I generally take a holistic view of transit–both bus and rail are part of the same system (as opposed to competing modes); many users of TriMet use both modes, and to some extent view the distinction as a bit artificial. But given recent history (with a rail expansion coupled with the current financial troubles resulting in significant reductions in bus service), a decrepit bus fleet (with many vehicles lacking modern amenities like A/C or low-floor boarding), and a political culture which has appeared to view bus service as second-class (along with politicians and business interests who may advocate rail projects for reasons other than mobility benefits), it is understandable that bus riders object vehemently to the practice.

There have been suggestions that TriMet discontinue the use of bus bridges altogether–or at a minimum, restrict bus bridges to use of “spare” assets, and refrain from taking busses and drivers out of scheduled revenue service. When a bus breaks down, after all, it is generally not replaced for a while–passengers on board are simply asked to wait for the follower. (If it is an infrequent line, or if the follower is SRO, this obviously becomes inconvenient). Local bus service, while being subject to ordinary traffic jams, generally doesn’t suffer catastrophic disruptions. An incident involving one bus does not shut down the line, and busses can re-route around road closures in most cases. One could argue that if riders are to enjoy the advantages of exclusive-ROW rail (no traffic conflicts and a smoother ride), they should also endure the disadvantage (the possibility of catastrophic failure of the service).

On the other hand, if you view things from the point of view of causing the least inconvenience to the fewest number of passengers; a bus bridge makes sense. A bus involved in a bridge will generally be more full than one circulating through the suburbs–in many cases, more passengers will benefit from the bridge than will be inconvenienced by it. On the third hand, the benefit is asymmetrical, as the same groups of passengers “win” and “lose”, time and time again.

One other issue is finance. Erik H, in a comment on the prior thread, proposes:

There’s a pretty simple solution:

Require MAX Operations (yes, Operations – not Capital) to buy 100 new buses.

Those 100 buses are then put into bus service – and DEDICATED to bus service. Meanwhile, MAX then takes possession of the 1400 and 1600 series fleet. They are stored at Ruby or Elmonica. They become MAX specific assets.

When MAX craps out, the MAX Operators get to drive those 22 year old POS buses – with zero impact to bus riders.

As noted above, the critical resource is drivers and not vehicles. TriMet does keep a number of vehicles in reserve, and reserve vehicles are more likely to be older ones (newer busses are run all day, older ones mainly during the peak and/or emergencies; this is a big reason why express lines, including the 94 which Erik commutes on, often use the dregs of the fleet). As Bob points out, vehicles are capital goods and should be bought with capital dollars–using operating funds to buy rolling stock is simply not wise. And TriMet doesn’t, to my knowledge, a priori dedicate X% of funding to bus and Y% to rail; its funding allocation strategies are more flexible. That said, Erik makes a good point: Any time a bus is used or diverted for bridging a rail outage, its corresponding expenses (fuel, driver labor, and pro-rated maintenance) ought to be “charged” to the rail accounts and not to bus service, in order to be an adequate representation of the cost of offering the different types of service. This may be TriMet’s practice today; it may not be. Given that a claimed benefit of rail is that it is cheaper to operate on a per passenger-mile basis, this ought to be true even if contingency measures are taken into consideration.


33 responses to “The whys and wherefores of MAX bus bridges”

  1. Since the limiting factor is drivers, maybe Tri-Met should pay a small bonus to its non-driver employees who choose to maintain current bus training and licensure, so they may be tapped for a bus bridge if there aren’t enough off-duty bus drivers immediately available. Take the bonus money out of the light rail operations budget.

  2. This is an excellent post and what it really illustrates that having bus and rail service under one management is NOT A GOOD POLICY

    And the term dispatchers use for removing buses from in service routes (which is a despicable practice as far as I am concerned) is cannibalizing.

    What you see before your own eyes is an agency that has expanded too far and now cannot operate efficiently.

    Very poor planning on the part of the people in charge of Trimet.

    This policy of their to “grab da money” because its available has come home to roost.

    Not only has it destroyed a once great bus service it has made Trimet unaffordable for many people as well as screwing over their retirees who thought they had earned the retirement that they left with.

    Trimet is a runaway train and the fact that nobody is stopping it just amazes me.

    Where is the governor, KITZHABER WHERE THE F’K are you?

    The union is a dysfunctional as Trimet managment and I have been wondering lately if there is some ‘smoke filled room deal’ between the union leadership and the Trimet leadership.

    It stinks, the whole mess.

    The bus bridges are ridiculous, they should get rid of them and just say:

    due to mechanical problems there will be no light rail service between point A and point B
    instead of this pathetic attempt to keep the thing ‘moving’. (if you want to call it that)

  3. My favorite buses are the old Flxibles! High floors and no AC, but smoother ride and more comfortable seats.

    Also, the doors are nicely fitted with large windows, and one does not have to push those damnable bars in order to exit at the back.

    They seem to be the prime movers on lines 52 and 88 west of Beaverton TC. I ride them whenever I can.

    “Dregs,” indeed!”

  4. The thing is about the rail here, the management is not going to do anything to jeopardize ridership.

    Hence all the amenities that you find nowhere else, like free parking. (obscene)

    Premium rail service for the cost of bus service (WES)

    They definitely have a double standard here and people that deny that rail gets preference are just fooling themselves.

    When you take a hard look at government now, what you will see is that it has no interest in serving the population. Not just at Trimet but at all government bureaucracies.

    There is an agenda behind the facade. In Portland its all about development at the expense of transit.

    Why would that be a possibility?
    Because development brings in new taxes. The reason they are allowing Portland to build and build is to increase tax base. Of course the whole place will be unlivable in 20 years.

    But to the power elite, they couldn’t care less.

    It’s always all about the money.

    The population is just there, ‘they’ pretend that they care, but the truth is they could care less.

    The population of America has been fooled into thinking we have a ‘democracy’. Nothing is further from the truth.

  5. I loved the 17/1800 buses!
    They were a problem on high density routes because of the stairs and the lifts are as slow as molasses but from a driving point of view they were the best of all the buses.

  6. Ok Scott but in the latest MAX breakdown I guess they can’t just abandon the riders over there.

    There is no alternative bus service on the yellow line is there?

    I guess you gotta have a bus ‘bridge’ (stupid name) for that situation.

  7. Actually, today’s MAX incident (this is Thursday, Nov 15 for those reading this in the future) is a car-on-pedestrian accident that happens to be blocking the tracks (or is close enough to the tracks that the police have closed the line).

  8. Once again, just like yesterday (with the West Side MAX), if Interstate Ave. was a BRT-Lite instead of LRT, the problem could have been more easily worked around.

  9. well the whole thing is over i dunno what to think about the bus bridge thing…they can’t just abandon people that live on the yellow line…but the concept has some serious flaws

  10. MAX operators are generally not available for a bus bridge–many may not have current training or licensing, and trains cannot be abandoned along the line.

    Neither of these are valid arguments.

    1. MAX operators are required to hold a Class B CDL or higher license to operate a light rail vehicle. I’m not sure if this is TriMet policy or State Law (since MAX vehicles operate on public highway right-of-ways). Thus, they are FULLY licensed to legally operate a bus in the State of Oregon.

    2. There is no reason a MAX operator cannot be required to fulfill periodic bus shifts to maintain their “training” (whatever that entails). Surely, someone who has driven buses for years is not going to forget everything they learn the second they walk into a MAX cab; and let’s face it – there isn’t that much training involved. This isn’t a difference between a Dash 8-Q400 (a small turboprop airliner used by Horizon Airlines) and an Airbus A380. And those MAX operators do drive public streets to and from work, so they clearly have to keep up with state motor vehicle laws. If necessary, have each MAX Operator required to fulfill one bus extra board shift per month (or quarter).

    3. In a hard shutdown, trains absolutely can be left along the line. The “real railroads” do it all the time when forced. Don’t believe me – just see what a railroad does for a major storm or earthquake. Remember the Oregon earthquake of 2001 or 2002? Trains were stacked up in Montana (I was living in Montana at the time, and on a conference call with my Oregon based manager when the earthquake occurred. The BNSF mainline from Whitefish east was stacked up, and the Whitefish yard itself was also filled up.)

    Let’s face it – nothing is moving. So why not tie down the trains at a station, secure the doors, and redeploy the Operators onto buses? Supervisors can shuttle MAX Operators to the nearest available bus; then Supervisors and Transit Security can deploy as necessary to protect MAX vehicles until service can resume. And absent a power outage (which would of course shut all the trains down where they are), the trains can likely make their way to a siding (pocket track) or yard or turnaround for storage, minimizing the number of trains left tied down on the main.

    The argument that “TriMet can’t pay bus drivers to stand around” is hollow when TriMet pays MAX Operators to stand around during a MAX outage while it can’t find bus drivers. Again – bus service declines, and bus Operations takes the budget hit in overtime pay and extra callouts, when the problem is 100% MAX related – and MAX Operations does not reimburse the Bus Operations budget. So again – bus takes a hit.

    And let’s not forget WES – a service that in daily standard operating procedure, each Engineer and Conductor are paid 33 minutes of “sitting around time” for every 90 minutes in service – 9 minutes for every turnaround in Beaverton, 24 minutes for every turnaround in Wilsonville. In essenece – that is time that could make an additional train run along the entire route, and still have five minutes to spare. So TriMet is no stranger to giving rail operations far more leeway than necessary in the same of “safety” to justify outrageous operating requirements, but when it comes to bus operations, the system is shortchanged in more ways than one.

  11. Erik, it seems like partitioning the job roles in that way would do little more than force the agency to give up some of the efficiency benefits of operating both the light rail and buses, and at the same time result in poorer responses to emergencies.

    How can supervisors ferry the MAX operators to the buses more quickly than just having whoever can handle it, handle it? (If they presently are just twiddling their thumbs, sure it would make sense to have them pick up slack and drive buses else go home.)

  12. The MAX voodoo doll is possibly being held near a sacrificial alter somewhere in the Teahadi Republic of Clackastan. Cursing the MAX is of course a privately held, high priest affair because magical electric propulsion strikes a paralyzing fear in the subservient mindset of fundamentalist republicans.

  13. The one biggest failure of the bus bridge concept is the inability to communicate to stranded riders REAL TIME information about the event and what they should do about it.

    Real time information is available on twitter via several transit enthusiasts that monitor Trimet operations @trimetscanner but there is no real time communication from the billion dollar agency.

    That’s the failure, inability to communicate to its public

  14. That stuff is the internal Trimet stuff,

    All that new stuff Trimet is getting is supposed to help them keep buses on decent headway’s.

    It has nothing to do with MAX.

    The bus bridges biggest failure is the inability of Trimet to communicate with riders on the ground.

    Maybe 1/100 has access to a twitter account that is connected to the Trimet Scanner Twitter account that is manned sometimes.

  15. >>Jim Lee Says:

    >My favorite buses are the old Flxibles! High >floors and no AC, but smoother ride and more >comfortable seats.

    >Also, the doors are nicely fitted with large >windows, and one does not have to push those >damnable bars in order to exit at the back.

    “Dregs,” indeed!”

    I wholeheartedly agree! I love the older buses. I like being up higher, but the best part about them is their roominess. The aisles are wider, the seats are more comfortable (and they seem roomier, too), the shape of the bus is more interesting (and somehow more calming, I think), and the ride is quite smooth. As for A/C, I don’t see what the fuss is. It rarely ever gets hot here (at least I don’t think so), and I wonder if it’s really worth the cost of operating and maintaining when opening the windows and ceiling vents works 95% percent of the time.

    If they ever get rid of the old, high-floor buses, I will be sad. I really like them a lot, much more so than the new buses, though I can understand why they are useful with level boarding. They’re just so cramped, though. It’s awful sitting in the aisle seat because one’s ass is not usually able to occupy the whole of the tiny seats. Heaven help you if your seatmate is fat. The newest buses are clean, though, especially the nooks in and around the windows. Why TriMet doesn’t use q-tips to clean those areas is beyond me. The windows are nasty usually with people’s greasy heads smeared all over them, and the grim in the window tracks. It’s amazing how clean new buses are. I’ve never seen such clean buses in my adult life (save once when taking a coach bus to a rich suburb of Minneapolis).

  16. For anyone who is not fully able, the low floor buses are a blessing. Want a higher seat? Sit in the back. The new buses have an intermediate seat which I like.
    Noticed that just about every morning a crash somewhere shuts down a portion of the regional freeway network. Indeed 50% of congestion in that network, according to ODOT, is incident related.
    MAX problems are the exception, not the rule.

  17. busses transporting passengers between two out-of-service segments on the line

    Don’t you mean “two in-service segments”?

    MAX trains are forbidden to travel backwards (against the signals) under normal operations (and certainly not with passengers on board)

    The tunnel is the only part of the system that’s reverse signaled. However, trains can run in reverse direction without signal protection, including in service. I heard this being done when a car high-centered on the curb separating the tracks at Interstate and Fremont.

    In addition, there are crossovers (such as along Burnside) where trains can be and are turned where necessary, in addition to starting/ending reverse running.

    The issues are that 1) many switches must be manually thrown or are time-locked (see http://maxfaqs.wordpress.com/2010/08/14/time-lock-switches/ and others), 2) trains must go slow and/or stop at intersections when on the other track and 3) it can be problematic to coordinate aw well as stop trains in that direction.

  18. Supervisors and mechanics still current on bus training and licensure, and thus legally able to operate a bus

    Don’t think this is ever done or maybe even feasible.

    When a bus breaks down, after all, it is generally not replaced for a while–passengers on board are simply asked to wait for the follower

    Not necessarily. Many times, especially during infrequent service, the replacement bus will pick up riders from the broken down one. The fill can run as late as necessary and allow the original operator to pick up the run where it would be best. Also, it’s not like the next trains will be coming either.

    When MAX craps out, the MAX Operators get to drive those 22 year old POS buses – with zero impact to bus riders.

    It seems Erik likes to punish MAX riders. But WES does have two 1400’s parked in Wilsonville.

    Moreover, especially with 40-foot (and sometimes less) buses, I’d doubt that there’s enough rail operators to fully staff a bus bridge (if that were even feasible).

    And operators would likely have to go through bus operation refresher training every 30 days–operating a bus is much different than a train.

  19. That chart reveals some disappointing trends, Al.

    What’s your opinion as to why MAX has suffered so much in that chart compared to other modes, given all the criticism which tends to (rightly or wrongly) support the conclusion that bus service has degraded more than MAX?

  20. Haha…
    I wish I had the answer to that Bob, I have some theories one of which is unhappy employees.
    I personally think that Trimet has stretched itself too thin, its just too big and basically unmanageable; they have made many changes there that have hampered the operations. Trimet really does need a management change, but we have a weak kneed governor who could care less about Portland transportation. Things are just a mess at Trimet and that chart is clear evidence just how much of a mess things are now. Anyway here is a

    cute light rail cartoon

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