sorting out rail-bus differences: endnotes

This post is an endnote to my post "sorting out rail-bus differences." Read that first.

I took as a starting point the results of an Infrastructurist survey, which gathered and published "36 reasons that streetcars are better than buses."  I used these to sort perceived rail-bus differences into three categories:

  • Misidentified Differences.  Issues such as propulsion and exclusive right of way that may differentiate a particular rail line from a particular bus line, but are not intrinsic to rail or buses.
  • Cultural Feedback Effects.  Differences that result from how people think about or perceive the difference.  These are profound influences on existing ridership, investment outcomes, etc. but come with the caution that culture changes but geometry doesn't.
  • Intrinsic Differences.  These few items, only 6 of the 36, really are rail-bus differences.

Several items on the Infrastructurist list are either duplicative or are combinations of several issues, so I streamlined them, and added others of my own, in producing the main post.   Several readers wondered why there wasn't a one-to-one correspondence between the items in my post and the original Infrastructurist items, so I've added these notes to show how my post derives from the original.   Bold is the original Infrastructurist text, followed in each case by my response in plain text. 

  1. New streetcar lines always, always, get more passengers than the bus routes they replace.  Cultural Feedback Effect.
  2. Buses, are susceptible to every pothole and height irregularity in the pavement (and in Chicago we have plenty). Streetcars ride on smooth, jointless steel rails that rarely develop bumps.  Intrinsic difference in "ride quality," though pavement can obviously be maintained to higher standards.  Score 25% Cultural Feedback Effect, 75% intrinsic.
  3. Streetcars don’t feel “low status” to transit riders. Buses often do.  Cultural Feedback Effect.
  4. Mapmakers almost always include streetcar lines on their city maps, and almost never put any bus route in ink. New investment follows the lines on the map.  Cultural Feedback Effect.
  5. The upfront costs are higher for streetcars than buses–but that is more than made up over time in lower operating and maintenance costs. In transit you get what you pay for.  Intrinsic difference, though with a lot of caveats, and certainly not universally true of rail-bus tradeoffs.  Score 50% intrinsic.
  6. There is a compelling “coolness” and “newness” factor attached to streetcars.  Cultural Feedback Effect.
  7. Streetcars feel safer from a crime point of view.  Cultural Feedback Effect.  If this difference in "feeling" results from differences in design unrelated to the rail-bus difference, such as better lighting at streetcar stops as opposed to bus stops, then this is also a Misidentified Difference.
  8. Steel wheel on steel rail is inherently more efficient than rubber tire on pavement. Electric streetcars can accelerate more quickly than buses.  First item is intrinsic, though the difference is not large.  Second item is mostly about propulsion, which is a Misidentifed Difference.  Score 50% intrinsic.
  9. Streetcars don’t smell like diesel.  Propulsion is a Misidentified Difference.
  10. Streetcars accelerate and decelerate smoothly because they’re electrically propelled. Internal-combustion engines acting through a transmission simply cannot surge with the same smoothness.  Propulsion is a Misidentified Difference.
  11. The current length limit for a bus is 60 feet, but streetcars can go longer, since they are locked into the rails and won’t be swinging all around the streets, smashing into cars.  Intrinsic difference, and the one most likely to be decisive.
  12. Streetcars have an air of nostalgia.  Cultural Feedback Effect.
  13. New streetcar and light rail lines usually come with an upgraded street experience from better stops, landscaping, new roadbeds, and better sidewalks, to name a few. Of course, your federal transit dollar is paying for these modernizations, so why wouldn’t cities try to get them!  Cultural Feedback Effect.
  14. Perhaps the most over looked and significant difference between street cars and buses is permanence. You’ll notice that development will follow a train station, but rarely a bus stop. Rails don’t pick up and move any time soon. Once a trolley system is in place, business and investors can count on them for decades. Buses come and go.  Cultural Feedback Effect.
  15. Streetcars are light and potentially 100% green. Potentially they could be powered by 100% solar and/or wind power. Even powered with regular power plant-derived electricity, they are still 95% cleaner than diesel buses. [Source? -Ed.]  Propulsion is a Misidentified Difference.
  16. Streetcars stop less. Because of the increased infrastructure for stops, transit planners don’t place stops at EVERY BLOCK, like they do with buses (SEPTA in Philly is terrible for this). Instead, blocks are a quarter to a half mile apart, so any point is no more than an eigth to a quarter mile from a stop.  Misidentified Difference.  To the extent that bus stops are too close together becuase planners think that buses are or should be intrinisically slow, this is also a Cultural Feedback Effect.
  17. People will travel longer distances on streetcars. At one point, in the 1930s, a person could travel to Boston from Washington solely on trolleys, with only two short gaps in the routes.  Cultural Feedback Effect.
  18. Buses are noisy. I ride them every day in Chicago, and I am constantly amazed at how loud a diesel bus engine is–even on our latest-model buses [and] the valve chatter is an irritant to the nervous system. By comparison, streetcars are virtually silent.  Propulsion is a Misidentified Difference.
  19. Technological advances already make the current generation definitely NOT your grandfather’s streetcar. Low floors are standard, for easy-on easy-off curbside boarding. Wide doors allow passengers to enter or exit quickly. So streetcar stops take less time than buses.  Misidentified Difference.  Good Bus Rapid Transit vehicles have all of these features; some even have doors on both sides.  The only difference that's intrinsic here is some limits on internal configuration required by wheelwells, but in a well-designed vehicle this doesn't affect boarding time.
  20. Passengers can take comfort from seeing the rails stretching out far ahead of them, while ever fearing that the bus could take a wrong turn at the next corner and divert them off course.  Cultural Feedback Effect.  Good Frequent Network mapping and BRT-level infrastructure for stops can equalize this for buses.  Note also that this supposed assurance provided by rails really works only in cities that have just one or two streetcar lines.  Streetcar-rich Toronto and Melbourne have tracks in so many of the streets that there are plenty of opportunities for a wayward streetcar to go off course, if you really want to be paranoid about that. 
  21. Once purchased (albeit at high cost) streetcars are cheaper to maintain and last way the hell longer (case in point, streetcars discarded in the US in the 40’s, snapped up by the Yugoslavs, which are still running).  Intrinsic difference.
  22. Streetcar tracks are cheaper to maintain than the roadways they displace.  Not if the streetcar tracks are in the roadway, where they are additional to the roadway rather than a "displacement" of it.  Score 50% of an intrinsic difference.
  23. People get notably more excited about the proposed extension of the streetcar system and expect revitalization of the neighborhoods around the planned stops.  This is practically the definition of a Cultural Feedback Effect.
  24. Streetcars create more walkable streets. This is because streetcars, as mentioned above, are more attractive to riders than buses, which in turns prompt to more mass transit usage in general, which in turns prompts to more walking–a virtuous cycle that creates more attractive city streets.  Cultural Feedback Effect.
  25. Most European cities and countries kept investing in public transit during the decades when America was DISinvesting. Now I look across the pond and see dozens of European cities extending or building new rail transit systems, including many streetcar lines, and conclude: ‘They probably know what they are doing; we should do some of that too.’  Cultural Feedback Effect.
  26. You know exactly where a streetcar is going – but have you ever tried looking at a bus route map?  Misidentified Difference.  To the extent that bus maps are incomprehensible because the transit agency mapmaker accepts the notion that buses are intrinsically confusing, this is also a Cultural Feedback Effect.
  27. Streetcars are faster than buses or trackless trolleys (aside from 2 lines in Philly, do any other cities run trackless trolleys, or trolley buses anymore?) because trams tend to have dedicated lanes. Even if they don’t, if they operate on streets with multiple lanes, people stay out of the tram lane, because it’s harder to drive a car along tram tracks (the wheels pull to one side or the other as they fall into the groove).  Right-of-Way is a Misidentifed Difference.  Driver behavior is a Cultural Feedback Effect. 
  28. In buses you’re still jostled by every pothole and sway at every bus stop. I thought bus rapid transit would be a significant improvement – there’s still a bit of sway and they concrete was not installed as smoothly as line of steel rail.  This is a duplicate of Item 2, which I scored 25% Misidentified Difference and 75% intrinsic.
  29. With buses transit planners are pushed by funding formulas to capture every pocket of riders thus you can get a very wiggly route – something that’s less practical on a fixed rail system.  Misidentifed Difference, arising from a Cultural Feedback Effect.  Tell your planners you don't want wiggly routes, and they'll be happy not to draw them. 
  30. Buses lurch unpredictably from side to side as they weave in and out of traffic and as they move from the traffic lane to the curb lane to pick up passengers. In streetcars turns occur at the same location on every trip, so that even standees can more or less relax knowing the car is not going to perform any unpredictable lateral maneuvers.  Score this 50% a Misidentified Difference, because much can be done to reduce lateral motion in buses (bus bulbs rather than indented stops for example.)  Guided busways are also out there as an option, one that's only now really developing.  Score 50% an Intrinsic Difference. 
  31. Most streetcar riders don’t consciously think about the differences between a bus ride and a streetcar ride. But their unconscious minds–the spinal cord, the solar plexus, the inner ear and the seat of the pants–quickly tally the differences and deliver an impressionistic conclusion: The streetcar ride is physiologically less stressful.  This is a complex mixture of propulsion issues — which are Misidentified Differences — and the Intrinsic Difference of ride quality.  Score 50% intrinsic. 
  32. An internal-combustion engine is constantly engaged in hammering itself to death and buses tend to vibrate themselves into a sort of metallurgical dishevelment. Interior fittings–window frames, handrails, floor coverings, seats–tend to work loose and make the interior look frowzy and uncared-for. By age 12 the bus is a piece of junk and has to be retired. A streetcar the same age is barely into its adolescence.  Propulsion is a Misidentified Difference.
  33. Streetcar stops are typically given more attention than most bus routes and the information system is more advanced. In Portland, the shelters even have VMS diplays that tell you the times of the next two streetcar arrivals. This valuable information gives people the option to wait, do something else to pass the time, or walk to their destination.  Customer information is a Misidentified Difference.  (Some major Portland bus stops also have real-time arrival displays.) 
  34. One great advantage of streetcars is that the infrastructure serves as an orienting and wayfinding device. The track alerts folks to the route and leads them to stops. Because they are a permanent feature of the streetscape, the routing is predictable and stable (unlike bus routes). So unlike a bus, a streetcar informs and helps citizens to formulate an image of their city, even if folks don’t ride it. It is a feature of their public realm. Because of this, these streets get greater public attention.  Cultural Feedback Effect.
  35. When you ride one of the remaining historic cars in Toronto or San Francisco you can tell they’re “old” in the sense of “out of style,” but when you look around the interior everything still seems shipshape, nothing rattles, the windows open and close without binding. The rider experiences a sense of solid quality associated with Grandma’s solid-oak dining table and 1847 Rodgers Brothers silver. And that makes everybody feel good. Unlike, say, an aging bus.  "Historic" is a Misindentifed Difference.  Maintenance effort is a Cultural Feedback Effect.  
  36. For those of you who cannot see the difference between a bus and a streetcar, I suggest riding a streetcar when you get the chance. Then, if you can locate a bus that more or less follows the same route, give that a try. Compare the two experiences.  This, indeed, is the starting point for this entire exercise.  Your bus and rail system have lots of differences, but most are not intrinsic differences between bus and rail.

That's how I got to the statement that six of the 36 are intrinsic.  There are many duplicates, which I counted, and many items that are mixtures.  There's nothing scientific about this analysis, just as there was nothing scientific about the process of developing the list of 36.  But I think the overall conclusion, that about a sixth of our impression of bus-rail differences is based on real and intrinsic bus-rail differences, is about right in my professional experience.

I feel the need to say, one last time, that to call something a Cultural Feedback Effect is not to imply that it's unimportant today.  These emotional factors may be supremely important, and if you weigh them consciously and decide that they should prevail, I have no reason to argue with you.  But when you decide to weigh a Cultural Feedback benefit above a geometric disbenefit (such as maneuverability in traffic), you're gambling that culture will be as constant as geometry and physics are.  And I wonder if that's true.

55 Responses to sorting out rail-bus differences: endnotes

  1. Jonathon February 12, 2011 at 5:31 pm #

    One comment regarding age, buses only wear out after 12 years because the typical american transit operator has no incentive to keep them longer, with government dollars helping them out to buy new ones. Toronto’s TTC was known for its bus-rebuilding program which was able to keep many of its old GM new look buses running 30+ years, with a few still left on the road. This is not quite, but almost at the 40-year lifespan pegged for the current generation of streetcars.

  2. BBnet3000 February 12, 2011 at 5:48 pm #

    San Francisco, famous for its streetcars, has basically proven how few benefits are intrinsic to rail with its rail system. Outside of the Market Street subway, most of them are street running, they are all slow (even the median running T really crawls and nobody knows why), noisy, and have high floors (with noisy stairs that sink down when the train exits the tunnel).
    Hell, they have even managed to mostly eliminate the capacity benefits of light rail, by having 2 car trains as the absolute maximum.
    This is mostly a rant but applies to a number of these, especially #36.

  3. Ryan February 12, 2011 at 6:01 pm #

    San francisco runs trackless trolleys and so do a few lines in boston run by the MBTA. I live in Boston and can attest to the annoyance when the quieter and smoother electric trolleybuses are swapped out for standard diesel and CNG busses. Unfortunately this occurs when the overhead has to be shut down for repairs or for other street work and every Sunday.

  4. Ben February 12, 2011 at 8:03 pm #

    Item #35 seems to assume that the streetcars in San Francisco have never been overhauled and are magically in excellent working order after 70+ years of operation. It’s obvious to me after riding them that they have had extensive maintenance done to the interior over the years.

  5. Anne February 12, 2011 at 11:09 pm #

    If you are looking for proof that most of the differences are cultural or misidentified, you need look no further than the TTC’s infamous 501 Queen Streetcar. People in my neighbourhood (Toronto Beaches) gladly pay double fare (yes, you read that right) to take the 143 Express Bus. The 143 Bus is so popular – even at double fare – that they had to put on an extra run 2 years ago.
    And they pay double fare to take the bus instead of the streetcar, not only because it is express, but because people at the ends of the line strongly dislike the streetcar due to its legendarily bad service problems and glacier-like speed.
    Every Torontonian can tell you stories about having to conduct traffic into oncoming lanes around 2 or 3 (or 5 or 6) bunched streetcars caught behind a parked car stuck in a snowbank.
    Our new mayor was elected with an historic voter turnout largely on a platform to kill streetcar/light rail expansion in Toronto. His very first meeting on his first day in office (7a.m.) was with the General Manager of Toronto’s transit system ordering him to immediately cancel Transit City – Toronto’s planned light rail expansion. Hardly a ringing endorsement, from the city which saved its streetcar system in the 70’s, of the advantage of surface rail over buses.–ford-s-first-day

  6. Darrell Clarke February 12, 2011 at 11:14 pm #

    An intrinsic difference you’ve missed is the ability of light rail track circuits to trigger crossing gates at grade crossings.
    Los Angeles’ Orange Line busway would have taken about 30 minutes end to end with gated crossings; with some signal priority for buses it takes some 50% longer.

  7. Anne February 12, 2011 at 11:25 pm #

    Re: my comment above – Toronto Mayor Ford’s Transportation Platform:
    Note his support of subways and buses (where subways are too expensive) over light rail/streetcars. The culture has most definitely started to swing away from streetcars here.

  8. anonymouse February 12, 2011 at 11:31 pm #

    Pretty much your entire discussion here is based around the assumption that there are two modes that we are comparing: streetcar and bus. Eastern European planners would beg to differ. Instead, they say that there are instead three modes: streetcar, trolleybus, and bus. The trolleybus is a mode in its own right, distinct from the diesel bus in its operating characteristics. In many respects it’s halfway between the streetcar and bus, but it’s not really similar enough to either one to just be grouped with it.

  9. Eric L February 12, 2011 at 11:34 pm #

    Jared, I mostly agree with your classification, but I think the cultural feedback effects may be more permanent than you give them credit for. That’s because, with the exception of a few like “newness” and “nostalgia,” the reason for just about all of them is the fact that the up-front investment for rail is higher. That isn’t going to change, and our tendency to make sure we’re getting the most out of the parts of the transit system we’ve invested the most in isn’t going to change. I suppose you might argue that the upfront investment in a bus line can be made high, too, but the reality is that because the upfront investment for bus can be so low, it will always be the case that most bus lines will be the low-investment kind, contributing to the feedback effect, and also anywhere BRT is ever suggested one of the main reasons offered is that the upfront investment can be lower.
    Not that I’m against spending a little to make our buses nice, I just don’t think it’s that likely the culture will ever come to expect that buses will be as nice as rail.
    The other thing is you make a big deal of propulsion being a mis-identified difference, but the reality is that electric trolley-buses are not the same technology. They dewire much more easily than pantograph based streetcars. Because of this, they also have a lower top speed than light rail. Maybe that will become less of a difference as ultracapacitors get better or we develop an inductive charging system, but for now there are intrinsic limitations of that technology as compared to rail. That said, they’re better at climbing hills, one of the underappreciated intrinsic differences between rubber tires and rail. (Or is that a misidentified difference, since rail can be propelled by cable or linear induction motors?)

  10. JJJ February 13, 2011 at 12:03 am #

    11 is wrong, los angeles operates 65 foot buses, and of course, cities around the world operate 80-90 foot double-articulated buses.
    Anyway, thanks for posting this. It also bothers me that when people compare bus vs streetcar, they compare their local crappy bus system with an idealized streetcar system, they’re not actually comparing apples to apples.
    An example of Toronto was given above, but heres one from Boston. The B line and the 57 run on the same road for a few miles (the train in the median, the bus on the side). Anyone who lives on that route will tell you that the 57 is ALWAYS faster. Well, except during an active snowstorm. But the rest of the year, ALWAYS faster. So there goes that “fact” (36).
    As for the “rail is permanent” bit, you might like this example for your book:
    It’s been cut down to 7, thats right, 7 runs a day.

  11. Dexter Wong February 13, 2011 at 12:25 am #

    San Francisco, Seattle, Dayton and Vancouver,BC still have trolley bus routes (as well as Philadelphia and Boston). San Francisco has expanded their use due to the fact they can climb steep hills more easily than other vehicles.

  12. Mikko Särelä February 13, 2011 at 12:53 am #

    I would like to argue against putting #14 as cultural.
    The feeling permanence comes largely from the fact that rail is heavy on capital expense that cannot be reused for other things, whereas bus operation is not-so-heavy on capital expense and heavier on the operating expense. Hence, it is easier politically to change bus service route than a rail service route.
    It’s a feature of almost any political system that cheap changes are easier to make than costly changes.
    As an example, a dedicated bus lane/street can be changed into a car lane/street just by an administrative decision. A dedicated street car lane is of no use for cars without rather large capital cost, unless it’s built on top of a lane usable for cars too.
    Hence, I would categorize this one at least 50% intrinsic.

  13. Jack Horner February 13, 2011 at 3:41 am #

    Add to intrinsic differences: ability of rail to fit better into a green corridor by putting grass between the rails.
    Like others, I’d be inclined to give ‘permanence’ (no 14) some score on instrinsic difference to the advantage of rail. But agree that permanence is mostly a function of the amount of investment: authorities are less likely to walk away from a transit service, the more capital is sunk it. Brisbane’s trunk line, high quality, grade separated, very expensive busways are pretty permanent.
    On diesel vs electric as misidentified difference: it is if your topic is “choice of wheel-road interface’. If you reframe the topic as ‘choice of propulsion system’, major differences are intrinsic. Now if there are good practical reasons why diesel is strongly associated with road buses and electricity is strongly associated with rail (see the comments on trolleybuses), then you can almost call it an intrinsic difference of bus vs rail, by association. You may choose rail in order to have the advantages of electricity.

  14. Danny February 13, 2011 at 6:51 am #

    As a huge and mostly biased rail fan, I still completely agree with the permanence issue. For example:
    and to see how a beautiful streetcar network doesn’t necessarily remain so, take a look at the evolution of the pittsburgh streetcar system:
    That being said, the solidity issue brought up in #35 is still a mixture of intrinsic and cultural feedback effects. The best way that I can explain it is by using a simple parallel with trucks. Since buses are almost inevitably built on truck frames, you can see the difference by observing the longevity of trucks. Even the most prideful owner-operator, the kind that maintains every aspect of his truck to near perfection…still will only keep his truck for between 10 and 20 years. This has nothing to do with how they maintain their vehicles (which, knowing some owner operators, is more obsessive than even the most cognitively-challenged PRT advocate), but rather a simple fact: trucks don’t last very long when you have to drive on roads.
    The longevity of a vehicle has a direct correlation to its ride quality. Every bump or jostle that you feel in the vehicle means a weakened welded joint, a loosened nut, a glued panel losing adhesion, etc. Two vehicles with exactly the same construction quality with the only difference being one on rail and one on the road, will have vastly different maintenance needs to keep them running at the same level.
    So yes, while we could say that buses could be maintained to higher levels to make them last longer (which sounds like a cultural effect), the reality is that at a given level of initial build quality and maintenance , a rail vehicle will always last longer. And that is, most definitely, an intrinsic difference.

  15. Anne February 13, 2011 at 7:08 am #

    Re: #14 “Once a trolley system is in place, business and investors can count on them for decades. Buses come and go.”
    That permanence goes two ways. The same cultural factors which give more weight to rail due to increased capital investment also generally prevent willingness to use (or even consider) buses when that rail system is in trouble due to faulty design, operation, etc… They’ll let that rail system, and the community it services, completely degrade before they will consider adopting, if ever, alternate modes. To get a taste of how this assumption in reason 14 can be wrong, read the comments on the following petition:
    Signatures with Comments:

  16. Dave February 13, 2011 at 8:40 am #

    @Danny, It seems you are saying it is impossible to build and maintain a bus roadway that is as smooth as rails. I wonder if that is true? Doing that may be more expensive than rail, which then is an intrinsic advantage for rail, but that is different than an intrinsic difference between the vehicle stock itself.

  17. ant6n February 13, 2011 at 8:45 am #

    You’re quite obviously biased against your Toronto streetcars.
    Firstly, Rob Ford was elected on a platform of austerity and “stop the gravy train” and stopping the “war on the car”; which appealed to large number of suburban voters in greater Toronto — those who never take the streetcar. He got much less support in former Toronto proper, despite the bland opposition candidates.
    Secondly, the unwillingness to abandon streetcar lines today is historical; many North American cities abandoned their streetcars systems in the 50ies and 60ies, replaced them with bus systems of such lower ride quality that the ridership tanked.
    Thirdly, there are some streetcar systems throughout the world that work really well, and it seems that the TTC is trying to move toward that model. They call it light rail, which is a bit dishonest, because it’s just streetcars in their own medians on low floor vehicles. The St Clair and Spadina routes – on their own right of way in the median of streets – have part of these ideas implemented. They both seem to be pretty successful, even if their development was a bit of a mess.
    The point is that rather than destroying the system, it makes much more sense to bring it up to a higher standard, which will improve ridership much more than to-bus conversions.

  18. Ted King February 13, 2011 at 10:52 am #

    @ BBnet3000 – Re : T-Third slowness
    I’ve ridden the T-Third and its predecessor, the #15 Third + Kearny. There are four main vulnerabilities to its route from Sunnydale to Fourth + King :
    1) Stoplights;
    2) Shared ROW (Hunters Point area);
    3) Drawbridges;
    4) Fourth + King itself, an overloaded intersection.
    Each of these could be improved but [a] the political will is not present and [b] neither is the money. The ugly reality of the T-Third is that it was built mainly as a redevelopment project without subjecting it to a transit sniff test.
    The T-Third is a poster child for what can go wrong with a line extension. I’ve sat through lengthy signal glitches at the east-side yard near Third + Army / Cesar Chavez. I’ve done slow boils over traffic clogs at Fourth + King that could have been avoided by a bypass track along the south bank of Mission Creek. That same bypass track would also provide some relief to drawbridge interruptions. Yes, it’s a comfortable ride from Sunnydale on up to downtown S.F. But they compromised the hell out of it by keeping the stoplights and the cross traffic.
    P.S. I suspect most savvy visitors to UCSF (Mission Bay) choose to walk from Fourth + King (Caltrain, N-Judah) / Townsend (10, 30, 45, 47) when the weather is decent due to the T-Third’s lack of reliability. Or they ride in one of UCSF’s shuttle buses.
    P.P.S. There is also the issue of vehicle maintenance that impacts the number of available cars and results in missed runs.

  19. Eric Doherty February 13, 2011 at 11:35 am #

    I think JJJ’s point is interesting and valid.
    Many cities run buses which are around 80 feet (24 meters)long. And other transit operators use double deck buses (e.g. BC Transit which serves the smaller cities in British Columbia, Canada).
    In BC, where I live, the longest buses are around 60′ but the container trucks are often around 80′ – even on crowded city streets. (They carry one 40 foot container and one 20′).
    So the vehicle capacity advantage for rail only becomes intrinsic once the capacity exceeds that of the largest bus commonly available. Regulations are cultural feedback.
    Eventually someone will probably build an ’80 long trolley bus with a second deck on the front section. Then the vehicle capacity advantage of rail would only apply to even bigger vehicles.
    The vehicle capacity advantage for rail is important, but only on quite busy routes.

  20. EngineerScotty February 13, 2011 at 11:47 am #

    A few more comments on Toronto, and on the subject generally.
    1) As ant6n notes, there was a noticed rural/suburban split in the Toronto mayoral election, with suburbanites voting for Rob Ford. (Ford won a plurality in a 3-way race but not a majority, FWIW–he’s still the lawful mayor of Toronto). Unlike many US “donut cities”, where the wealthy mainly live in the suburbs, Toronto has most of its wealth living closer in. Ford’s campaign involved quite a few anti-elitist themes, and one relevant cultural difference between bus and rail is that rail transit is often viewed as a signifier of wealth and privilege. Never mind that the TTC streetcars are a legacy system that is paid for (and long predates the use of busses in transit applications), calls to knock the elites down a peg by “taking away their toys” have some appeal.
    2) With regard to comparisons between express bus and local-service rail transit (or the equivalent compare, between commuter rail and local-service bus)–there really isn’t any meaningful comparison which can be made. They are two different modes of service, and the fact that an express service can offer a quicker trip downtown for suburban commuters doesn’t make it “better”, just better for those sorts of trips. This dynamic (along with the express bus not stopping in rough neighborhoods in some cases) often produces the result that a bus line can be perceived as a more premium service than rail, an inversion of the usual North American cultural expectations. And it’s also frequently a cause of suburban opposition to rapid transit lines, which often replace pre-existing express services in the same corridor, as many suburban express users simply aren’t interested in a service that stops anywhere besides their favorite park-and-ride and their downtown office.
    3) One other relevant difference (again a cultural effect, but one which doubtless informs Mayor Ford’s anti-streetcar diatribes) is the typical design of stops. Why, might one ask, would the replacement of mixed-traffic streetcars with local bus service on the same routes be considered a victory for motorists, and a defeat for those forces waging the “war on the car”? Especially when you consider the capacity differences? A big part of this has to do with stops. It’s common practice (though certainly not an intrinsic technological difference) for streetcars to stop in-lane, but for busses to pull over to the curb. This contributes to the perceived higher comfort level of rail (fewer lateral forces imposed on passengers), but more importantly, it inconveniences motorists more. Cars aren’t inconvenienced by a bus that stops out of the lane–if anything, the transit users are inconvenienced because the bus then has to negotiate its way back into traffic. Even in places where a bus leaving a stop is given the right-of-way, it still is an impediment to faster and more reliable service.

  21. Joseph E February 13, 2011 at 1:28 pm #

    Re: 19 “…Low floors are standard, for easy-on easy-off curbside boarding… So streetcar stops take less time than buses. Misidentified Difference. Good Bus Rapid Transit vehicles have all of these features…”
    Jared, I think this one may include 50% intrinsic difference. Even here in Los Angeles, where the Orange Line and the Silver Line have dedicated platforms and buses, we don’t have level boarding. From what I’ve seen, the BRT systems in Colombia and Australia don’t have it either. I think it requires a “fixed guideway” (tracks)
    Level boarding allows wheelchairs to be loaded quickly, without any special ramps, and this can save 60 seconds at a stop where a wheelchair boards or exits. Not all trains and platforms allow level boarding (e.g. Amtrak), but almost all new light rail vehicles and streetcars do.

  22. Jarrett at February 13, 2011 at 2:10 pm #

    Joseph.  No, you can achieve level boarding with optical guidance systems to get the bus lined up close enough to the curb, and with the curb raised to match the bus floor.  Las Vegas is working on it, I believe.

  23. JJJ February 13, 2011 at 4:47 pm #

    Jack: You can have a busway with grass. Once again, a cultural thing, not intrinsic.
    Joseph, the Mexico City and Curitiba BRT systems allow for level boarding, and with less of a gap than the los angeles light rail system.
    Note the “bridge” in the curitiba BRT buses.
    There is also a lift for wheelchairs to enter the raised station. Some stops just use a standard ramp (which obviously requires more space).

  24. JJJ February 13, 2011 at 4:50 pm #

    Heres a better photo of the curitiba bridge level boarding system.
    Again, the majority of US light rail systems require a similar type of ramp for full wheelchair access. The difference is that the curitiba ramps are on the outside of the bus, so they ALWAYS deploy. The US buses and light rail vehicles require a separate operation.

  25. Alan Robinson February 13, 2011 at 7:17 pm #

    I’m not sure if you’ve riden TTC streetcars. I have and all the points that Anne has brought up are valid. There is no bias as I see it. Streetcars in mixed traffic in Toronto are significantly slower than similar bus routes (such as the Bay route) in the downtown core.
    @EngineerScotty, point 3)
    In Toronto, it’s not just that streetcars have to stop in a lane, but that they stop in the centre lane, completely blocking any other vehicular traffic while stopped.

  26. Brent February 13, 2011 at 7:53 pm #

    Another inversion of rail vs. bus preferences:
    GO Transit (commuter rail and bus network in Toronto and suburbs) operates an express bus between Hamilton and Toronto along the Queen Elizabeth Way highway (QEW). This generally parallels a standard commuter rail line between Hamilton and Toronto, although most trains turn back before Hamilton.
    A few years back, the provincial Ministry of Transportation announced major construction on the QEW that would have increased delays and decreased reliability on GO’s Hamilton express buses, so GO proposed taking bus service off the QEW and shuttling Hamilton riders to the nearest major station instead (probably either Aldershot or Burlington, don’t remember which one) where they would take the train to Toronto. They cancelled the plan when riders said they preferred the bus, thanks — would take the added travel time and potential reliability problems since it meant continuing a one-seat ride, would have operated more frequently (more convenient), and for that matter the bus-train trip wasn’t any faster than the bus-only trip.

  27. EngineerScotty February 13, 2011 at 9:23 pm #

    They cancelled the plan when riders said they preferred the bus, thanks — would take the added travel time and potential reliability problems since it meant continuing a one-seat ride, would have operated more frequently (more convenient), and for that matter the bus-train trip wasn’t any faster than the bus-only trip.
    This demonstrates that many quality-of-service factors frequently trump mode choice; in this particular case the audience was used to the bus, and therefore by definition didn’t contain riders with a disinclination to ride the bus.

  28. Jack Horner February 14, 2011 at 3:38 am #

    ‘Capacity per vehicle’, no. 11, may link to legibility and user-friendliness of the system, in some situations.
    On a busy inner city shared route section three buses pull up at once. Mine is the third. Am I meant to sprint 30 metres to hop on, or will it pull up again at the head of the stop? And if the little old lady tries the former, and the bus driver waits for her, and then a fourth and fifth bus pull up behind…..
    This is a very stressful and inefficient situation.
    If every three buses become one LRV, the problem is much reduced.
    An alternative is leap-frog bus stops: ‘Routes A, B & C stop here. Routes D, E & F stop 100 metres further along.’ This makes the system less legible, and infrequent users may spend some time walking up and down trying to find the correct stop, while the bus they wanted speeds past.
    Busways don’t solve the problem without clever stop management. I understand this is a serious problem at some points on Brisbane’s high quality, very expensive busways.
    It all depends on the total situation. If 150 buses per hour on the inner city shared section spread to 5 different lines at 30 per hour, a light rail conversion looks good. 150 is far too many for the shared section (in mixed traffic); and reducing each line from 30 to 10 per hour is no big deal in waiting time.
    If 100 buses per hour spread to 10 different lines, it’s more doubtful, because reducing each line from 10 per hour to 3 increases waiting time too much (assuming that the unshared extremities of each line are important to total ridership). Or you go to a trunk/feeder setup.

  29. Alon Levy February 14, 2011 at 6:55 am #

    You should turn propulsion into its own category, separate from the other three. The reason is that it is an inherent difference between diesel buses and LRT, and almost invariably the people who prefer buses to LRT prefer diesel buses and not trolleybuses. More importantly, many of the advantages of buses over streetcars, such as lower capital construction costs and the ability to run through to any street, disappear or are much smaller for trolleybuses. (In hilly cities, of course, trolleybuses have a separate inherent advantage – they can climb the highest grades.)

  30. Tom West February 14, 2011 at 7:45 am #

    So the real differences seem to be:
    1) Streetcars are more likely to have a smooth ride than buses (both in terms of bumps and lateral motion)
    2) Streetcars tend to have lower operating and maintence costs per passenger/seat
    3) Streetcars can be built much longer than buses (and hence carry more passengers)
    … and that’s about it. Anything else a streetcar can do, so can a bus.

  31. Alex B. February 14, 2011 at 8:11 am #

    On the life of vehicles, does anyone have insight as to how electric trolley buses compare to diesel buses?
    I know the poor ride quality of a bus also ends up wearing down the structure of the vehicle. However, I was also under the impression that the propulsion source mattered a great deal. Buses with diesels are literally shaken to death by their propulsion source.

  32. anonymouse February 14, 2011 at 9:52 am #

    One other argument for trolleybuses being a separate mode is that they are almost never considered as an option for bus improvements or BRT, even in cities that already have them. In San Francisco, the Geary BRT proposal does not include electrification (though it does include curvy, stylized “BRTVs”) even though the city already has a huge trolleybus network and knows the advantages of the mode. The Van Ness BRT proposal has trolleybuses, but only because Van Ness already has trolleybuses.
    Boston has a similar case: the Silver Line has wires, but only in the underground portion. Dual-mode buses were going to be necessary anyway because they run on a freeway, but even the routes that do not go to the airport still switch to diesel, even though the run outside the tunnel is fairly short and electrification would have allowed the use of cheap trolleybuses rather than expensive dual-modes.

  33. Alan Robinson February 14, 2011 at 9:55 am #

    @ Alex B.
    Propulsion systems are definitely the first things to go in most vehicles. For most agencies, the progression of standard bus technology (from small buses up to the GM New Look to low floor buses) has meant that it was more suitable to purchase new buses than to refurbish the old. Even when refurbishing old buses would be appropriate, most transit agencies don’t have the expertise or manpower to do it.
    The obvious exception to this is Toronto. They have the Hillcrest yard that performs heavy overhauls almost all of the TTC’s buses and electric motors. To overhaul a bus, they replace almost everything except the frame and windows. This option is cheaper and more reliable than buying new vehicles, but not by that much.

  34. Eric Doherty February 14, 2011 at 11:14 am #

    anonymouse wrote: “One other argument for trolleybuses being a separate mode is that they are almost never considered as an option for bus improvements or BRT”
    Here in Metro Vancouver, Canada, this has been a big fight, but advocates of transparent decision making have made some important gains. A few years ago trolley BRT was not on the table, now it is explicitly one of the options on all the rapid transit lines under consideration (except one where the provincial cabinet unilaterally decided to use light metro, despite not having the funding in place to build it). People seem very comfortable with the descriptions explaining that BRT buses can be diesel/natural gas, hybrid, or trolley powered.
    This change happened because of citizen pressure combined with open minded professionals on the inside of the transit agency, municipalities, and at the planning school.
    If you want trolley buses to be on the table, you have to speak out loud and clear on the issue.

  35. Simon February 15, 2011 at 9:26 am #

    Thanks Jarrett for the two really good posts on what the real differences between buses and trams/trains are, and why buses are often the best option.
    One thing that I think is often acknowledged but not fully thought through is that buses are intrinsically more flexible. And that this is both an advantage and a disadvantage.
    Flexibility advantages of buses – can use existing infrastructure, can extend existing infrastructure more easily, can eliminate extra connections, can flow out onto ordinary streets, and can manoeuvre around obstacles to name a few.
    Are also the disadvantages – can end up with too many routes converging on the same place causing bunching, can lead to the temptation to add direct routes to everywhere, routes can be changed, infrastructure can be used for other things, infrastructure can be changed to mix use and obstructions can be tolerated to name some.
    These advantages and disadvantages are different sides of the same coin. It is not to say that the disadvantages will happen, it is just easier for them to happen because buses are more flexible.

  36. TransitPlannerMunich February 15, 2011 at 10:37 am #

    The city of Ulm opened in 2009 a new tram line extension, replacing a bus linie
    running there (that had before also a direct connection to the city center by
    bus with basically the same time needed to get to the center compared with the
    tram – okay, the tram is one minute faster). Modern, low floor buses,
    proof-of-payment, were in use before they were replaced by the tram. Tram and
    bus are/were both running every ten minutes.
    One year later the amount of passengers were counted (only) at the new tram
    stops (the tram stops are identical with the old bus stops).
    Surprise, surprise: 43% more passengers within one year.
    For those of you able to read German, here is an article about that:,-43-Prozent-mehr-Fahrgaeste-_arid,2274734_regid,13_puid,2_pageid,4503.html
    That is all I have to say about that topic.
    If you want transit acceptance, you have to face this reality. However strange it seems to you.

  37. Jarrett at February 15, 2011 at 2:21 pm #

    Was there a change in the throughput of seats per hour, due to running larger vehicles at the same frequency?  If so, and if the buses were crowded, the outcome you describe could be partly the result of the capacity addition. 
    If not, then it's a cultural feedback effect, which is fine.  Again, I'm not arguing that these outcomes don't occur, I'm just trying to categorize the actual effects of tram vs bus in a useful way. 

  38. EngineerScotty February 15, 2011 at 4:18 pm #

    I was going to write a response here (to the entire post), but it got too long and got moved to the old blog instead. Shorter version: Non-intrinsic differences may seem irrelevant or specious in the abstract; but in the context of specific projects or systems, often become very important.
    There’s one other interesting factor–decidedly a cultural feedback effect, but a big one–and that’s perceptions of prestige among decision-makers (who may have different views of things than the public at large or of the current ridership). The Portland Metro area is just starting planning for what is now being called the Southwest Corridor–a new rapid transit line connecting Portland to its southwestern suburbs, specifically Tigard and (possibly) Sherwood or Tualatin. At the current stage of the planning, neither route nor mode has been determined, but it is widely believed that the line will be the next (after the Milwaukie project) extension of MAX light rail; and not anything else. (“Rapid streetcar”, BRT, and commuter rail are all mentioned as alternatives).
    Why? Some critics charge developer pork, but the biggest reason is that the city of Tigard will scream bloody murder if they get “stuck” with bus, when other suburbs such as Beaverton, Hillsboro, Milwaukie, Gresham, and Lake Oswego have (or are getting) rail projects. This has nothing to do with the technical merits of the modes (and there are plenty of reasons why a busway in the corridor would make sense), and everything to do with issues of prestige. After the original N/S corridor was disapproved by voters in the 1990s, Metro considered BRT for the Milwaukie project–until Milwaukie begged them to reconsider.
    OTOH, another upcoming rapid transit project–the Powell Line, may well actually be BRT: Why? For one thing, it goes through lots of dense urban fabric, so BRT would be less disruptive; but for another, it’s entirely within the city of Portland, which no longer needs additional rail within its borders to signify its status within the region.

  39. Michael Druker February 15, 2011 at 5:34 pm #

    “If not, then it’s a cultural feedback effect, which is fine.”
    Really – it has to be a “cultural feedback effect”, not noise, comfort, more room to move about? I don’t like the handwaving you are doing to suggest that every mode difference that you don’t feel is sufficiently technical must be something cultural and superficial.
    I think the distinction would be much more supportable if it was between “hard” and “soft” differences. But describing everything difficult to quantify as being cultural is assuming too much.

  40. Corey Burger February 16, 2011 at 4:01 am #

    Part of the problem with characterizing things as “cultural” is that there is a certain class of person who will immediately discount any “soft” reason. Unfortunately for transit advocates, it is often exactly this group of advocates that can make/break a project. So while I understand what you are saying, I wouldn’t have called your streetcar vs bus post “an inconvenient truth”. That is a pretty loaded title and is a great soundbite -A soundbite which is going to bite a lot of transit advocates in the ass.

  41. JesryPo February 16, 2011 at 6:47 am #

    The funny thing is, most of the arguments laid out so thoroughly here sound a lot like those made by those in the mid 20th century hoping to replace street rail transit with rubber tire.
    Yes, it makes a lot of sense on paper, but at least in the United States, a nearly a century of choosing bus over rail has been a phenomenal disaster in most cities, helping to decimate denser precincts and hampering the redevelopment of inner-ring neighborhoods.
    And the ironic thing is, ripping up streetcar lines for buses was in its own way a cultural phenomenon – they were seen as “modern” in their day.

  42. JesryPo February 16, 2011 at 9:04 am #

    Also, while I understand the premise to be differentiating between INTRINSIC differences and those perhaps less tangible, I would point out that rail HAS to have things like fixed routes, orienting lines (you walk by and see those tracks in the street – you know that you are on a transit line), fewer stops, upgraded station infrastructure, to name a few. These are actually INTRINSIC for rail.
    For bus transit, these are an option – and actually an UPGRADE. A city could easily downgrade a BRT to standard service by letting the distinctive paving color fade, adding intermediate stops, etc., but cannot be so cavalier about ripping up rail tracks.

  43. Chris H February 16, 2011 at 12:45 pm #

    “But when you decide to weigh a Cultural Feedback benefit above a geometric disbenefit (such as maneuverability in traffic), you’re gambling that culture will be as constant as geometry and physics are. And I wonder if that’s true.”
    I would say that the cultural feedback effect is in fact a huge, and incredibly constant impact on human behavior, and probably more important than geometry and physics, which in the case of transit, can usually be overcome with money or technology.
    After all, isn’t the “cultural feedback effect” the reasons why we have cities in the first place? I don’t think there’s anything “intrinsically” superior about the location of Rome, or the southern tip of Manhattan, that make them special places to put a city or a skyscraper?
    They exist because of the feedback effect. And if Rome burns down, you build it right back in the same place it was before, because you know that the other Romans are going to be working with you doing the same thing. And you don’t build a skyscraper on Staten island because you know that the “cultural feedback effect” will be working against you, and the cultural feedback effect is hugely important, and very real.
    So, I would agree that a big part of the difference between rail and busses is cultural. But so is most of the difference between Manhattan and Staten island. And if an earthquake destroyed Manhattan’s “intrinsic” benefits, I would still bet my money that the cultural feedback effect would make Manhattan a better investment, for now and into the future.

  44. Anne February 16, 2011 at 12:54 pm #

    Your comment “I would point out that rail HAS to have things like […] fewer stops, upgraded station infrastructure, to name a few. These are actually INTRINSIC for rail.” needs a slight modification (IMHO) to “These are actually INTRINSIC for *properly-designed* rail”.
    In Toronto the oldest streetcar lines (King, Queen, College/Gerrard) have very frequent stops (often closer together than similar bus routes) throughout their entire lengths (which are entirely too long considering) and almost no station infrastructure, with a few exceptions. These two design flaws are (again IMHO) what make TTC streetcars disliked by many of their users – especially those riders travelling outside of the downtown core. If those were changed I believe much of the pushback against streetcars would diminish here.
    Once again, sadly, our experience here illustrates that not all of those items point to intrinsic differences.

  45. TrabsitPlannerMunich February 16, 2011 at 1:04 pm #

    nice try, but it is about the last (or first) stops in Ulm. And the buses there were definitely not overcrowded. And yes, the tram has larger vehicles compared to the bus. And they are needed, with 43% more passengers.
    Basically, I am not interested in whatever the specific reason is why modern trams are accepted more than buses. And I do not care if you call those reasons “cultural” or whatever. Maybe buses are superior compared with trams and the US transit planners were right over all the last 70 years. But I see what works and what does not. And in the end the customer, the transit rider, is always right. So I would give them what they “buy”. If they would love to ride big pink buses with plastic elephants on top, I would try to get some. For the moment (and the last decades at least) it seems they are going for trams. So give them modern trams if you want that they get out from the car. In Munich they want trams and underground trains. Trams with the overall and by far best grades from our riders when asked about the preferred mode of transit vehicles. Even more than our nice and fast and clean and effective wonderful underground metro system. I like our buses, we transport over 400,000 passengers annually with each bus in service. But… it will not get people from their cars
    Remember the car industry – can you really tell what is the logic behind the fact that some cars sell better than others? Why people by oversized, too expensive cars? Why some manufacturer could double the price and still sell their stuff, others give heavy discounts and still do not sell enough – even if their cars bring you perfectly well from A to B, cost less, need less gas, are fast enough for 99% of your trips and have enough space for 99% of your needs? No real logic behind, but when you want to sell cars, do not question the decisions of your customers but give them what they buy. Or you will be out of business fast. The only reason why bus transit companies are not out of business is cause of the tax money. Did I mention, by the way, that the operating costs of Munich’s tram and metro are fully covered by farebox revenue…

  46. anonymouse February 16, 2011 at 4:28 pm #

    @TransitPlannerMunich I think what Jarrett is trying to say is that what customers really want is not “trams” or “buses” but a service that is fast, reliable, comfortable, etc., and that their desires can be met with either mode, given the appropriate level of investment in each one.

  47. Alon Levy February 16, 2011 at 10:27 pm #

    Chris H, the gist of your comment is right, by Lower Manhattan does actually have an intrinsic benefit: the schist bedrock is very close to the surface, making it easier to build skyscrapers without very deep foundations. The same is true for Midtown.

  48. M1EK February 17, 2011 at 11:08 am #

    @anonymouse and what Jarrett is trying to hide is the fact that nobody’s seriously buying the contention that a bus can be made to be as nice as a train. If it were possible, somebody would have done so by now.

  49. TransitPlannerMunich February 17, 2011 at 2:52 pm #

    I understand that perfectly well.
    Bascially I believe in giving people what they want.
    And, as I mention, if people would go for blimps, I would advocate blimps in public tranist. If they go for buses of any kind I would also support this.
    But unfortunately it seems that public transit is the most successful with rail.
    And a bus that has all the advantages of rail is already invented. It is called “tram”.
    But if it makes you happy, buses CAN really attract passengers. Look at this one – higher capacity than any tram I know (even more than the Bupadest tram worms):
    Or check out those buses, perfect combination of bus and rail:
    But please not this one – combining perfectly the disadvantages of buses with the disadvantages of rail:

  50. Art Busman February 17, 2011 at 4:58 pm #

    One important psychological difference btwn street cars and buses is how cramped and claustrophobic buses feel. You often step up to a bus and the aisles are narrower. Retail stores had studies showing how narrow aisles forcing people to brush against each other create discomfort. Especially as Americans are getting wider, buses are becoming unbearably narrow. I’d argue a third of Americans are forced to take up 1.5 seats on a typical US bus. The doors also tend to be wider on streetcars creating a more open, airy feel. The one drawback for streetcars/rail is the seating arrangement that has you either facing backwards or directly facing another person which is just as discomforting as brushing against people.

  51. EngineerScotty February 17, 2011 at 5:23 pm #

    The doors also tend to be wider on streetcars creating a more open, airy feel. The one drawback for streetcars/rail is the seating arrangement that has you either facing backwards or directly facing another person which is just as discomforting as brushing against people.
    Of course, seating arrangements and door spacing have little to do with the type of wheels or the fixity of the guideway. There are plenty of examples of busses with center boarding.
    Technically, vehicle width has little to do with it either, although in practice, busses (and to a lesser extent streetcars) tend to be narrower than LRV or heavy-rail vehicles, given the need to operate in mixed traffic, while giving sufficient margin of error to avoid collisions.

  52. anonymouse February 18, 2011 at 12:37 am #

    One drawback of low-floor buses is that the space above the front wheels is effectively wasted, and that’s potentially four seats’ worth of space. It also means there’s a bottleneck at the front of the bus, which is where people board in the US. This a pretty hard geometric constraint on space tradeoffs, and it really is determined by issues of pneumatic tires versus steel wheels. Steel wheels are smaller, but usually somewhat closer together than pneumatic ones.

  53. Zoltán February 18, 2011 at 6:00 am #

    This is well dealt with on the trying-to-be-a-tram vehicles in Leeds, which put the driver over the front wheels:
    (Note how the street layout seems explicity designed to prevent good ride quality!)

  54. Pete March 2, 2011 at 2:18 pm #

    A couple of other UK solutions to front wheel arch intrusion are the Optare Solo and the Wright Streetlite, both with the front axle ahead of the doorway:
    Solo interior
    The Solo also comes as a hybrid
    Very quiet in operation – comparable to tram/streetcar
    Stretlite interior

  55. Alexis April 20, 2011 at 11:31 am #

    I somewhat disagree with #29 being solely a feedback effect. I agree that if people ask for less wiggly bus routes, they can definitely be produced. But if people ask for more wiggly rail routes, they probably can’t be produced cost-effectively and so the designers will just say no in the name of efficiency. Standard buses (not BRT, ROW-separated) will likely be fighting the efficiency vs. serving more populations fight for a long time. You get these debates in rail situations too (see Harold St Station example on the Portland-Milwaukie light-rail project) but less so and differently. I’d say this is 75% cultural and 25% intrinsic, rather than wholly cultural.