Double Deckers as Express Buses

A guest column overviewing double-decker bus technology.
Today we are proud to feature a guest column by longtime contributor Ron Swaren, who writes on the subject of using double-decker busses for express and high-capacity routes, especially as a substitute for articulated busses. –EngineerScotty

London is famous for its intra-city double decker buses. They have not really been used for long distance, express route to suburban destinations yet are popular with visitors to London proper. It’s a bit hard to use surface transport for suburban routes in London, anyway, since the city measures 50 miles from west end to east end. Many of the bright-red Routemaster buses have also been sold around the world, showing up often as tour buses with the top removed.
The iconic Routemaster bus was introduced in the early 1950’s, but various concerns have finally led to its replacement with updated technology. Several new models have been recently introduced. According to blogger Bridgette Meinhold:

Transport for London has been working on a new, more efficient, double-decker bus for London to replace the classic Routemaster. Today, London Mayor Boris Johnson and Transport for London officially unveiled the new bus co-designed by The Wright Group and Thomas Heatherwick. The new design uses the latest in green hybrid technology and will be 15% more fuel efficient than existing hybrid buses, 40% more efficient than conventional diesel double decks, and much quieter on the streets.

Another new model in London is the Volvo B5L (Wikipedia) According to, these busses “feature a parallel hybrid I-SAM (Integrated Starter, Alternator, Motor) system, which uses an electric motor and a hybrid engine to power the vehicle. The buses can go up to 12mph in electric mode, after which, the diesel engines steps in. The speed of 12mph might not sound like much, but it is quite perfect for most bus routes.” (Image courtesy of Volvo).


In the Pacific Northwest, British Columbian cities, Kelowna and Victoria, are both using Alexander Dennis Enviro500 models, as is Everett Washington, which has ordered 23 vehicles. Toronto, Canada has 22 in use. The Enviro 500 are also seeing use in Las Vegas and in two communities in Southern California. In Asia there are probably hundreds, if not a few thousand of this model in use. Hong Kong has a total of over 4000 double-decker buses in its fleet.

Another popular DD model, often used in a touring configuration, is the Van Hool TD925. One of these was at the Oregon Convention Center a couple of years ago as part of a nationwide tour. New York City has tested them out but not committed to their use. A video of one of these in action can be seen here:

But what about express use on US freeways? Well, take a look at Commmunity Transit (Everett. WA) which will place 23 “DoubleTall” busses into use this year, commuting from Everett to Seattle via I-5. These are rated at 73 seated passengers, or 90 total. Community Transit also claims 11 percent less fuel usage and 26 percent less maintenance than an articulated bus. I have seen the passenger rating for similar buses in Berlin as up to 128 persons. Here is how Community Transit sums up the features:

Twice as Smart: The double decker can seat 73 and accommodate 90 passengers total in the same footprint as a 40-passenger bus. This means it will take less fuel to transport more passengers while taking up less space on the road… an important advantage given the ever-increasing traffic in the region.

36 responses to “Double Deckers as Express Buses”

  1. I assume that these double decker buses would have bike racks that can hold double stack / tall bikes. Correct?

  2. As an express bus the use of a double-decker would make a lot of sense for a number of reasons:

    1. Those riding a further distance would hopefully graviate to the upper level, keeping the lower level clear for those riding a shorter distance.

    2. Dwell times at stops are typically longer on express buses as they have larger number of riders board at the same time.

    On the other hand, articulated buses make more sense for high-capacity local routes (the 12, the 33, the 57, the 72 – where TriMet used to run the 700s) because articulateds can board and deboard faster. They also run on wide streets where the size of the articulated bus is not as much of a concern (where in London it was a big deal; that’s why TfL is phasing out the articulated buses).

    Seattle has had issues with articulated buses in cold weather, but San Francisco runs articulated buses on hills with no problem. Portland never seemed to have the problem; however Portland does not have the hilly downtown terrain that Seattle has (where downtown is one big long slope to Elliot Bay) and the artics were kept on the Sunset Highway and T.V. Highway, Barbur Boulevard, Powell, McLoughlin and generally did not go onto local streets.

    Relating back to BRT, TriMet would do well to make small improvements on selected routes to even “BRT-Lite”, like LACMTA’s “Rapid” service, which was demonstrated to provide huge ridership increases while improving bus service in a cost-effective manner. Even still, LTD has articulated buses on non-BRT routes, as does the Spokane Transit Authority, King County Metro, Community Transit, Coast Mountain and others. Portland might be able to get away without having a general articulated bus fleet because it can focus its fleet and service offerings.

  3. Hong Kong uses double-decker busses almost exclusively for its high-capacity routes, I’ve never seen an artic there. (Less popular routes use standard 40’/13m models and smaller).

    A better way to speed up boarding time on high-volume routes might be to switch to proof-of-payment on these routes. Doing so would require onboard fare machines like the Streetcar, but would permit all-door boarding. (Exact-change cash fares could still be paid to the driver). And such bus routes could be added back to Fareless Wahtever.

  4. Most reports concerning the inauguration of DD’s on express routes cite a generally favorable reaction from the public. How much this continues in the long run, I am not sure. I suppose there are a lot of variables that come in to play; yet as modern features and amenities are incorporated in as they come into the market, I would think that would help DD’s to remain as a popular transportation alternative.

    I think the very latest London versions do feature rear boarding. Perhaps a roving ticket checker would be sufficient to ensure payment. Apart from equity considerations, The capacity of these vehicles could allow their service to become marginally profitable if used only at the highest traffic times, and servicing stops with the greatest number of boardings. One example I was thinking of would be an express service from Sherwood and Tualatin via I-5 with perhaps another stop at the Barbur Bv Transit Station.

    Of course with a bus you could adjust the routes for greatest effect. There can always be non-express service for those who are unable to get to a Park and Ride location.

  5. This could be just the kind of novelty factor that could lure more bus-wary people onto the bus. I rode one of these in Las Vegas (the “Deuce”) and it was a nice ride. Riding around Portland in one would give a whole new perspective on things…

    Just how tall are these, compared to trucks? Do traffic lights or anything else need to be moved up or out of the way to accommodate them?

    I wish Portland would do *something* new with the bus fleet. Sure, we’re getting new buses, but they are only a very minor update to the existing ones. No articulated buses (anymore), no double deckers, no BRT, no hybrids — other than the handful we got for free as part of a settlement. I love light rail and everything, but it’d be nice to see some sort of substantial bus progress.

  6. The double-decker being used by Community Transit is 14′ tall, same as your garden-variety semi, so vertical clearance isn’t a problem for most places. (That said, there’s probably a few places in town where it would be a problem).

    There was an accident last September in New York State, where a double decker bus slammed into a low-clearance rail trestle, killing four passengers on board. In this particular case, the bus was an intercity motor coach, not local public transport, and the driver apparently got lost and struck the trestle in the dark. Every few months, it seems, you read about semis getting stuck under low bridges when drivers get lost or don’t pay attention–when the portion of the vehicle that strikes a bridge has passengers rather than cargo, it can be dangerous. OTOH, there’s plenty of bad things that can happen to plain vanilla 40′ busses as well, so I’m not sure that concerns about lost double-deckers striking bridges and having their tops shorn off ought to dominate the discussion.

  7. One concern about DD’s is the decreasing ability, due to age, weight, etc. of our society to walk up a flight of stairs. Also, a number of relatively fit and young riders seem to have no problem using the seats close to the bus driver on current buses but sometimes forget to offer them to people who need them.

    Another factor might be the comfort level of some passengers to be in a part of the bus well away from the driver yet sharing the space with others perceived in a less than positive light. This hasn’t seemed to be a make or break issue for streetcar or MAX ridership, but it is a concern for some.

  8. Just how tall are these, compared to trucks? Do traffic lights or anything else need to be moved up or out of the way to accommodate them?

    I don’t think significant accommodations are needed. There are at least two double-decker buses in this area already (one of them is a Routemaster), and I’ve seen them traveling around downtown. So clearance shouldn’t be that much of a problem.

    Given the boarding issues, I expect double-deckers make the most sense for long-haul, limited-stop service with high passenger volume and enough daily service to make it worth buying a new bus. I don’t know how many potential routes in the system meet those criteria.

  9. That Second Level is gonna make some nice drug dealing real estate. It is already a danger to ride MAX at night with Gang peps / no help from Drivers , what do you think would happen here.

    no one would go up there.

  10. The accidents have occurred when there has been a route change—such as due to highway closure—or when an untrained driver has taken over. I would be more concerned by a combination of a steeply banked curve and icy conditions. And that is a good argument for using them in express type conditions. Hwy 99E, for example, is fairly flat—or at least unbanked— all the way from Oregon City to Downtown Portland. The Interstate 5 route has little banking all the way through Portland. I suppose the Terwiliger Curves, in very hazardous conditions, could present some problems. Using Barbur BV to bypass the T. curves, could be an option.

    They do try to keep the center of gravity low. I don’t know if there is much analysis of these vehicles in hilly, mild winter climes. Maybe there are some studies from Berlin since they have used them extensively in the past and keep a fairly large fleet today.

    The MegaBus compnay which used the Van Hools, I think, in its NorthEast and Chicago area service has reported three accidents in the last year. One was due to inadequate overhead clearance.

  11. Here’s a tip for billb: Double-decker buses are in use in cities all over the world and have been for generations. Including western cities. Including western cities in which people have been known to buy and sell drugs, listen to strange music, look and talk tough, occasionally behave badly, and otherwise annoy.

    MAX is ridden by a great many people, including at night, despite the scary assertions you make.

    There’s nothing to indicate that Portlanders wouldn’t ride on the top deck just like people do in any other city with double-deckers.

    Less fear and more facts, please.

  12. I saw double deckers in Scotland and the UK in 2007 and took a few photos. The first is in Glasgow and the others in Plymouth. Note that the design also allows for a much larger overhead sign and a potential increase in landscape for advertising. (And pretty colors!)

  13. Even older double-decker busses are equipped with mirrors so that the driver can see what’s going on on the upper level. (I’ve sat at the front of several older models in HK; and there’s a vertical viewport leading to a 45 degree mirror directly above the driver). More modern busses probably do better than that with closed-circuit television onboard.

    Regarding hilly locales. The Tuen Mun Road in Hong Kong’s New Territories is a six-lane freeway hugging the west coast of the Kowloon Peninsula. The road is built into the side of a cliff, and has numerous sharp curves and steep grades–it’s topography makes the Terwilliger Curves look like New Jersey Turnpike. Dozens of double-decker busses ply this highway every hour without incident (though they annoy the hell out of drivers behind them when they slow down to climb the numerous steep hills en route). I’ve ridden this route many times in my life–it was a little scary the first time, especially when stting in the front of the upper level, but now it’s entirely unremarkable.

    Seven years ago, there was a terrible accident where a bus (an artic, not a double-decker) ran off the side of the road and over the cliff, killing 21–however in this case, the bus was ran off the road by a truck driver.

  14. Maybe C-Tran could buy some double-deckers for its Portland Express routes. Do any of those lines have the ridership to make that kind of investment beneficial?

    It is already a danger to ride MAX at night with Gang peps / no help from Drivers

    Speaking as someone who has been riding MAX at night from downtown (or sometimes Beaverton or Hillsboro) to Gateway several nights a week for well over a decade, I have NO idea what you’re talking about.

  15. Personally, I worry more about road rage incidents on the freeway (or on local streets) than I do about hoods causing problems on transit.

    And I’d rather have a druggie or drunk riding on the bus or train than behind the wheel of two tons (or more) of metal.

  16. Does anyone know how much more weight a double decker bus places onto the roadway than a regular or articulated bus? It seems to me that gains in efficiency may also equate to more road maintenance.

  17. The Van Hool TD 925 has a GVWR of 57,000 lbs and a max weight on the drive axle of 24,000 lbs. I’ve been looking for figures for Tri Met buses.

    Observing the wear and tear on area freeways it seems that the observable ruts tend to be in a narrower pattern than the 100 in. wide + or – track of an average bus would be. I think most of the rutting we see around here is due to studded tires—at least on the concrete surfaced highways. Maybe a little extra wear outside of those ruts wouldn’t hurt?

  18. Busses probably don’t cause much wear and tear on freeways, simply because they aren’t the dominant users of them–and because much of the damage caused by busses occurs where they stop, as breaking shifts much of the weight to the front axles.

    But this is a big concern over artics–which have more axles to distribute their weight across. 57,000 pounds is nearly as much as a Streetcar weights, and Streetcars have twice as many effective axels (2 per bogey) and run on a surface (steel rails) which is not as easily damaged as is pavement.

  19. I think there are solutions to the wear and tear problem. In fact, if the bi-level capacity is only used when needed, there wouldn’t be that many trips per day anyway. Put them aside during midday and evenings and let the single level buses do their job.

    Speaking of which, there is the “nitronic” design i.e. stainless steel, which was developed by Oak Ridge Labs. 30 percent lighter than a conventional design.

    The Enviro 5000 are 51,000 lbs.
    The sleeker, ultramodern London buses are supposed to be “lightweight.”
    I think there are solutions, although with a relatively high centre of gravity you wouldn’t want it to be too light. But the technology is there to make other buses lighter in weight, so any damage caused by public transit buses should, on the average, be more controllable as time goes on.

  20. Indeed, nice post! :D

    I would like to point out the obvious-some lines aren’t going to be able to handle some routes.

    Like lines 33/99. The Bybee/McLoughlin Bridge is a really small bridge, at least from what I’ve seen and remembered. Would it be safe to put the buses under those bridges? My inclination is probably not. Some of the things we take for granted on most bus routes can be a real problem is the bus is twice as tall.

    But these would definitely work, and it would just be fun to have.

  21. The Bybee crossing was reconstructed a few years ago and has improved clearance. (Although it may create the impression of shaving a few heads in the right-hand southbound lane, I think it would be OK.)

    See this Google Street View of SE Bybee over 99E.

  22. The old Bybee bridge had clearance issues; but the new bridge (built in 2004) has adequate clearance (>14′) for semis and double-decker busses.

    And double-decker busses are generally not twice as tall as single-decker busses. All the busses discussed in this page are 14′ or less, the maximum height of a non-oversize vehicle in the US. The various 40′ single-decker busses operated by TriMet are all in the neighborhood of 10′ (3m) or so, with interior heights in the neighborhood of 6 1/2 feet. One issue with double-decker models is that they aren’t well suited for very tall people, having cabin heights not much more than 6 feet; whereas low-floor busses are typically 8′ floor to ceiling near the boarding doors (6.5′ above the wheels).

  23. I just came across one of the privately owned double deckers on NW 23rd yesterday. I was surprised to see that it easily cleared the streetcar overhead lines, branches, traffic lights, etc.

  24. Talked about these at METRO today. Couple points:
    1. The Alexander Dennis Enviro’s are now “US made” i.e. at least assembled in the US, apparently beginning in 2008:

    This takes place at the ElDorado National Plant in Riverside, CA. I”m not sure what the typical passenger capcity is; one tested in Australia was rated at 80 seated and 44 “standees”, albeit with limited headroom.

    2.Was also asked if they are ADA Compliant. Haven’t found a specific statement but since they are used in several US communities, now, I’m assuming they are.

    Apparently Alexander Dennis is making the push for the US market. I guess the rest of the world has already caught on…enough for the other manufacturers, anyway.

  25. I’ve lived in Davis, CA and Hong Kong, both of which use double decker buses extensively. I love double deckers. Davis just added 2 of the Alexander Dennis buses to their fleet, ADA compliant.

    Double decker buses really work better than single deckers for a couple reasons —
    * 50% more seating per road space taken up.
    * They look really cool.
    * Kids love to ride them.
    * You can see out the front and the back.
    * You’re a head and shoulders above the rest of the world. Cool as heck.
    * You feel like you’re floating along above traffic in some sort of a boat, or dirigible.
    * and, to quote the original General Manager of the Davis fleet, who convinced everyone to buy a couple and ship them over from England in 1967, “They have cachet.’

    Untrans started out with schoolbuses for student transit. Nobody rode them. They bought double decker buses. Everyone loved them.

    Now that Davis has some new double deckers in revenue service, maybe other systems will order them as well. One benefit Davis had is that their shops were built for double deckers — if Trimet bought some they’d need to work on them outside, or make a taller garage.

    Here’s a link to the page on the DavisWiki with some photos and history (photos of the new ones)

    Ted Buehler

  26. engineer scotty wrote

    >> The Tuen Mun Road in Hong Kong’s New Territories is a six-lane freeway hugging the west coast of the Kowloon Peninsula.

  27. A couple google street view shots of the Tuen Mun Highway.

    If anyone likes to see pics of double decker buses in heavy haul revenue service, you can poke around on streetview in Hong Kong, there’s a bus in pretty much every image.

    That’s another thing about double deckers — the scenery is a lot better. Since you’re higher up, you can see more, see farther, see over most other vehicles, and you hardly even see the road.

    & here’s some double decker trams, for good measure —
    * Happy Valley terminus,114.184577&spn=0,0.032508&t=h&z=16&layer=c&cbll=22.26984,114.184074&panoid=OExSda7GemQ9sBzaixIEhQ&cbp=12,128.74,,0,0.78
    * Hennessey Road,114.177754&spn=0,0.032508&t=h&z=16&layer=c&cbll=22.278265,114.177646&panoid=HEt-DtUABDNxixpTWyGknA&cbp=12,229.45,,0,5
    * Sheung Wan,114.15149&spn=0,0.032508&t=h&z=16&layer=c&cbll=22.286774,114.151384&panoid=p9gh3Ia8m1xsjELlsWYtfg&cbp=12,271.79,,0,3.81

    Ted Buehler

  28. Another factor might be the comfort level of some passengers to be in a part of the bus well away from the driver yet sharing the space with others perceived in a less than positive light. This hasn’t seemed to be a make or break issue for streetcar or MAX ridership, but it is a concern for some.

    It hasn’t discouraged MAX ridership on the second car who are even more removed from an Operator than the top level of a double-deck bus (who are in the same vehicle as the Operator).

    Does anyone know how much more weight a double decker bus places onto the roadway than a regular or articulated bus?

    A New Flyer D40LF comes in at about 27,000-28,000 pounds empty weight.

    The Alexander Dennis is reported about twice as much, but still well under the 80,000 pound legal load limit for state highways. Routes like the 9, 12, 33, 57, and 72 are all largely or mostly operated on state highways.

  29. Double deckers are great for express service where people board and deboard at only a few locations. So like Ron says, a Sherwood-Portland express service would be an excellent use for them. If Clark County would get off its butt and give the C-Tran buses a priority route to the bridgehead, it would be worthwhile for C-Tran to buy some too. Same reasoning.

    But they’re horrible for “POBS” because everybody going a mile of so crams into the lower deck; typically the “scenic” upper deck is almost empty on midday London buses. I realize that London has no choice because of its limited street capacity, but three door artics are the way to go where there is room and a need for capacity.

    • The irony in Vegas is that the double deckers on the strip are the ones that stop at every stop and the express bus is a longer articulated bus. So opposite of what your saying.

      • The double deckers in Las Vegas are a special case, because they’re tourist runs, and of course tourists don’t mind climbing the stairs and love the view.

        Just use your brain; which is likely to load and unload the same number of passengers more quickly: a bus with three doors spread evenly throughout sixty feet of vehicle or one with two, one of which leads to a curving stair?

    • I keep saying that bus service could be EXPANDED with the right planning. Stop with the unfounded criticism, too. I sometimes rode the bus to work in what is now the Pearl District, back in the 1970’s at a RECYCLING business on 14th and Hoyt. SO stop it! And when I have been in foreign cities I use public transit.

      I don’t think length of ride (say 15 minutes as opposed to 12) is nearly a negative as waiting a long time for a transfer to come along. That is why I say that the completion of our metropolitan ring road thru NW Portland would HELP mass transit—and it also helps cycling. If you don’t have to waste 15-20 minutes waiting for a transfer wouldn’t more people opt for a ride, as opposed to fighting traffic? But when you block out huge areas of the metro. region with no–or limited roads—there is nothing for the transit bus to go on.

      A Ring Road means traffic headed to other points does not go through the urban core. It is used by hundreds of cities, and would be considered fundamental in any transportation planners education. Of course, if you are in a city where there is a huge natural boundary, you don’t have a ring road. But the Tualatin Mts. are not a significant barrier.

      But let us look at effective express routes: Washougal and Camas could be connected to Gresham MAX pretty easy with a bridge in that area. St. Helens, Scappoose and Linnton could easily be connected to Beaverton and Hillsboro with a Western Arterial Hwy. The overall usage during the day might not be high, but at least there could be commuter service. And, as I testified at METRO today innovation is proceeding apace in road transit. China just introduced some aluminum, electric powered buses. And Quebec’s TM4 is getting well established as an alternate energy producer, including heavy vehicles. Bosch says it will be able to double the energy density of li-ion batteries in five years, and there are other types. I saw an article on ultra capacitors that used recycle tire material for anodes.

      Something is going to happen. It already is in other cities. Portland is not necessarily a leader.

      • Ron,

        You can claim all you want that these roads you love to tout will be filled with buses whizzing masses of commuters to work in ecologically sound comfort. But it is a fantasy. Without severe congestion the people traveling on them will drive.

        And if they can drive from Clark County to Intel, with David Madore in command up here, Clark County will fill up with ticky-tacky all the way to the North Fork of the Lewis River.

        And that would be one more ecological rape to add to the long vicious history of the region’s exploitation. You wanna build more houses, go to Houston or Dallas. They’re building houses there like there’s no tomorrow — BIG luxurious houses with lots of the hand crafting you love and are good at. And the land surrounding them — especially Houston — is not much good for food production. Clark County, like the Willamette Valley, on the other hand though it can’t compete with the San Joaquin Valley can raise many things that people eat. It should be preserved in the say way that Oregon has preserved the fine agricultural land of the Willamette Valley.

        I know you don’t agree, and that’s fine. But don’t make up crap about the people who live over here. Damn few of them care one whit about anything except their own convenience and comfort.

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