Here's a crucial passage from the book I'm working on, though it may will end up in the next book rather than this one [Human Transit]. The topic is emotive, so I'm trying to be very carefully factual here. I welcome your critiques in comments. If you disagree on a matter of fact, please provide a reference to a source.
In 2009, the then-popular [but now defunct] blog the Infrastructurist asked its readers whether streetcars are better than buses, and why. Readers came up with 36 responses (listed verbatim here) that formed a good summary of popular perceptions about the rail-bus distinction.
Of the 36 reasons, only six refer to an intrinsic difference between bus and rail technologies. All the others fall into two categories, which I’ll call misidentified differences and cultural feedback effects.
In your city, the rail system has lots of differences from the buses, including technological differences. But that doesn’t mean that all these distinctions are true rail-bus distinctions. For example:
- Propulsion: electric vs internal combustion. In most North American cities that have both bus and rail, the rail is electric but the buses use internal combustion (diesel, “clean diesel,” or various forms of natural gas). Electric motors have obvious advantages – in emissions, noise, acceleration, and comfort – but none of these are true rail vs. bus differences. Rail can be run by internal combustion, and buses can be electric. If you want to compare your electric rail option with a bus option, compare it to electric trolleybuses. If you want to compare your internal-combustion buses with a rail option, compare them to internal-combustion rail options such as the Diesel Multiple Unit (DMU).
- Mixed-flow vs exclusive-lane operation. Transit speed and reliability are mostly a result of how much you stop and what can get in the way. Rail is more often run in exclusive rights of way, but some streetcars run in mixed traffic and some buses run in exclusive lanes. Monorails never get stuck in traffic, but neither do buses in Brisbane, Australia’s busway system. Most city buses can get stuck in traffic, but so can any streetcar, tram, or light rail vehicle that runs in a mixed traffic lane. (A major problem for BRT in North America is that people keep taking junkets to Latin America, where BRT is powerful but the economic context is too different, rather than to Brisbane, where they could see high-end BRT working in a wealthy city.)
- Off-board “proof of payment” fare collection vs. “pay the driver” fare collection. Fare-collection style has big psychological effects. “Pay the driver” slows down boarding and is a greater hassle for all concerned. Some rapid transit sytstems (rail and bus) provide paid areas with faregates, eliminating this delay. The other solution is “proof of payment,” which means that you buy a ticket on the platform (or already have a valid ticket) but you only show it if a roving “fare inspector” asks to see it. If you don’t have one, you pay a fine. Rail is more likely to use “proof of payment” than buses, but there are exceptions both ways, and there’s no necessary link between the rail-vs-bus choice and the fare collection system. High-capacity bus systems are beginning to shift to “proof of payment” fare collection to eliminate fare-related boarding delay. UPDATE: San Francisco now uses proof of payment on its entire bus system.
- Frequency and Span. Your whole rail transit system may be frequent, while some your buses aren’t, and in that case, you’ll naturally associate frequency with rail. As we saw here, a good Frequent Network map, which shows both frequent rail and frequent buses, will clear up that confusion. Buses can be very frequent, while some rail services can run infrequently or peak-only. (We usually call those commuter rail.)
Cultural Feedback Effects
A community’s attitudes toward rail and bus technologies can easily affect they way they are operated and presented. In short, people who believe that rail is better than buses will tend to act in ways that make that belief true. For example;
- Differences in investment or care. A community that believes that buses are only for poor people, or that rail is the mode of the future, will under-invest in buses as opposed to rail, producing a difference in quality that will reinforce that belief. It may also hold bus operations staff to lower standards than rail staff, and encourage other cultural differences between bus and rail operations that become real for the customer, but are not intrinsic to the bus-rail distinction.
- Perceptions of permanence. If you don’t stop to think about it, rails in the street will make a service feel permanent, especially if you’re used to hearing people tell you that rails imply permanence. History clearly shows that rail systems do stop running if their market disappears. True permanence lies in the permanence of the market, and that lies in the pattern of development [See Human Transit Chapter 14].
- Perceptions of legibility. The notion that a bus might do something unpredictable and a railcar won’t is also a cultural feedback effect, typically the result of insufficiently clear and compelling information about the bus network. It is quite possible to build bus services with such a high level of investment in infrastructure, such as stops and stations, that the routing is as obvious as a rail line’s would be; the Los Angeles Orange Line bus rapid transit system is a good example.
- Regulatory differences. Government regulation often enforces different rules for road transport as opposed to rail transport. These regulations are themselves a kind of cultural feedback, differences in habit and history between agencies that regulate roads and those that regulate rail. By enforcing different standards and safety requirements, these regulations can cause outcomes that amplify the apparent difference between road-based and rail-based transit.
- Different potential for mission-creep. If you build a stretch of road for a busway, there’s always a danger that somebody might try to open it to cars. If you don’t trust your government to protect the stated purpose of a facility, this can be a major decision factor. This issue applies, however, to the narrow range of cases in which a road or lane is being built that could be useful to cars but is closed to them. It is not an issue where the proposal is to reallocate existing roadspace from cars to transit, nor when building a higher-end busway whose design makes it useless to cars even if they were allowed on it.
Intrinsic Bus-Rail Differences
When we set aside those two categories and look at the differences that really follow, intrinsically, from the rail-bus distinction, there appear to be seven, and only the first three of them are always to rail’s advantage:
- Capacity. Where demand is high, rail can serve that demand at a higher ratio of passengers to on-board staff, which means that once you absorb the (often large) construction cost, you will be able to offer greater capacity for a given operating cost. A transit vehicle that’s too crowded to board doesn’t meet any of our seven desires for useful service, so this point is often decisive in favor of rail.
- Ride quality. Ride quality in buses is improving, and guided busways may give buses an even more rail-like feel, but new rail systems will probably always have an advantage with their smoother running surface. Is the smooth ride of rail indispensible to a useful network? This can be a tough question whose answer may vary from one community to another.
- Limited energy-efficiency and emissions consequences tied to the difference between tires and steel wheels. Again, the primary factor governing energy-efficiency and emissions is propulsion (electric vs internal combustion), which is not intrinsic to the rail-bus difference. However, there is a small range of differences that arise from the physics of steel-on-steel vs tire-on-road operation, and that favor the former.
- Noise from wheel friction. Most noise impacts are due to internal combustion, which either rail or buses may use, so that’s a misidentified difference. Rail transit lines that intersect streets may be required to install noisy crossing signals — a valid response to the extreme weight of commuter rail trains but more controversial as applied to light rail. These regulatory requirements may be cultural feedback effects. But rail has a further noise disadvantage that really is intrinsic: the tight fit between steel wheel and rail causes noisy friction when going around curves, especially when going fast.
- Some variable cost differences. Broadly speaking, bus-based projects that use portions of existing roadway will be much cheaper than building rail for those same segments would be. Beyond that, costs for bus vs. rail projects can be hard to compare. Capital costs for rail include vehicles, while a busway is sometimes run with an existing bus fleet. Certain bus-rail comparisons in certain corridors may turn up significant differences in operating cost that may be valid in that situation, but need to be checked carefully to ensure that they assume the same factors on both sides.
- Maneuverability around obstacles is a specific issue for rail in mixed traffic, usually light rail or streetcars. In mixed traffic, minor obstructions routinely occur in a lane, especially if the lane is adjacent to on-street parking. People stop in the lane to make deliveries, get into and out of taxis, and parallel-park. Accidents and breakdowns happen. If these events block a streetcar, the streetcar is stuck. A bus, in the same situation, can often go around the obstruction and continue.
- Ability to extend existing infrastructure. If you’ve already built rail on a large portion the length of a travel corridor, it may be logical to build rail on the rest, so as not to create a technologically required connection. On the other hand, busways can often eliminate extra connections because buses can run through the busway but then flow out onto ordinary streets. In each case, an advantage goes to the technology that makes better use of the infrastructure that already exists, whether road or rail.
Of course, in a particular transit debate, you may not have all of the choices that I’ve articulated here. Still, it’s important to remember that most of the things you hear about why rail is better than buses are not true in the abstract, as facts of geometry or physics that follow from intrinsic differences between roads and rails.
It may very well be that rail is culturally better than buses in your city, in which case all you’re really saying is that people in your city think rail is better than buses and will therefore tend to act in ways that make that true. If you’re interested in appealing to your current population, and motivating them to make investment decisions based on their current perceptions about the benefits of rail, that may even be a good reason to build rail even if you don’t need its intrinsic benefits.
But if you’re thinking in longer-range terms, don’t forget: Attitudes, assumptions and perceptions will change over time. Physics and geometry won’t.
UPDATE! See endnotes for this post here!
Under Cultural Feedback Effects, you’ve missed/ignored the propensity of building bus infrastructure to in turn build up entrenched political and economic interests that refuse to consider anything else than buses.
Buses are inherently more likely to do this because some bus fanatics will be tempted to argue that a bus can do anything a train can do and more, whereas even the most extreme railfan will continue to acknowledge a role for buses. This line of argumentation on the part of bus fanatics will inevitably find adherents in the political structure, and, over time, can be difficult to overcome. Buses, for all their flexibility on the road, limit flexibility of the mind. Need an example? Take a look at Ottawa. It has been like pulling teeth to get any rail in Ottawa at all. Meanwhile, light rail-using Calgary is quite willing to also consider bus infrastructure as part of its transit mix.
And speaking of flexibility, you mention that buses can go around obstacles but in practice what that means is that buses need to go around more obstacles because people are more willing to put obstacles in the path of buses, or are ignorant that they are even doing so.
Very good articulation of some common misconceptions. A big factor that isn’t mentioned, however, is economic effects (is this in the next chapter?). “Permanent” infrastructure–dedicated BRT lanes, streetcar rails, etc.–appears to stimulate development and add economic value to an area better than non-permanent infrastructure like a basic bus line. The new Los Angeles Streetcar Economic Impact Report is an excellent analysis of these added effects http://www.lastreetcar.org/2011/02/08/downtown-la-streetcar-economic-study-released/
I think you are too dismissive of the cultural aspects of the rail v bus debate.
I really think that for whatever reason, humans “bond” with “things on rails” and not busses. And this preferencial bonding shows no sign of changing. As a proof point: How many steam train museums, streetcar museums, and rail museums exist? Must be hundreds if not thousands in the U.S. How many cities run historical streetcars? At least a few in the US. Now reverse the question. How many bus museums are there? Any? How many cities run historical buses or even have historical buses? Any?
Model railroads: G scale, S scale, HO scale, O scale, On3 scale, N scale, Z scale.
Model buses: Zip.
Humans love trains. Humans hate buses.
This may be “cultural” but is shows no sign of changing in the last 100 years.
In the article, you mention 36 criteria, but only give 16 bullet items–what are the other 20? (Or do we have to buy the book? 🙂
You haven’t mentioned, of course, the whole class debate (bus is for poor people) which frequently gets cited in these discussions. There’s a good argument to be made that this isn’t a valid reason; OTOH it seems to be an article of faith (with some research, albeit disputed, to back it up) that all else being equal, rail attracts more ridership. Obviously this is dependent on cultural context, and is a fine example of a feedback affect (I can think of numerous places where de facto transit apartheid is in effect), but it’s there.
David, in my experience quite a few of the “more busses, less rail” arguments coming from “bus fanatics” as you put it, are often proxies for arguments about where service should go. Ignoring groups with non-transit-related objectives for prefering bus (such as conservatives looking to minimize capital costs, or transit unions concerned about jobs), a big source of anti-rail attitudes comes from poor city residents who believe transit should be concentrated in dense urban areas, particularly low-income neighborhoods. To them, rail represents either a) gentrification or b) reallocation of service to the suburbs; they often take the POV that rail is all about attracting yuppies to the service (or about doling pork to political patrons), and of little benefit to existing riders, who mostly use the bus.
Most regular Brisbane transit users I know favour buses over trains as they are more frequen. It’s only the infrequent users who tend to favour trains. That’s a pretty strong indication of perceived versus actual advantages.
Technology: Rail is NOT noisier wrt to steel wheel on steel rail.
There are lots of lubrication system to do track head and side rail lubrication. For example, http://www.portecrail.com/Lubrication/lubfm.htm lists the benefits:
You have also misidentified Maneuverability around obstacles as a technology issue. I have seen a few eastern european tram operators (with a beefed up front-end or in many cases a beat -up front end) be more than willing to use their mass to move a parked car out of their way. Similarly but less damaging, a police officer w/ radio riding in the streetcar (or bus) combined with a motivated towing service will quickly make short work of a vehicle blocking a track or bus lane. A month of aggressive enforcement will help the city budget and eliminate any need to worry about maneuverability.
Some rail “dis”advantages:
I don’t think you’re right to dismiss perceptions of permanence of rail vs. bus as purely a cultural factor. Certainly a rail line can discontinue service and a bus line can have its route remain fixed over the long term. But empirically, I would suspect that the number of years before a route is altered is quite a bit higher for rail. (No citation.)
My take would be that there is an intrinsic feeling of permanence associated with rail, regardless of the actual future of the service. Most of the talk about permanence is people communicating the feeling, not promoting rail as permanent. I don’t think there’s any question that the feeling of permanence affects choices people make, such as where to live, where to locate, and whether to buy a car.
In the places where transit is only starting to get a foothold, I think the differential potential for compromise of rail vs. bus deserves more serious consideration.
(In my area, the same people who were loudly advocating for Bus Rapid Transit as a cheaper alternative to a light rail corridor have made clear that they don’t want lanes taken away for buses either. Support for a cheaper transit solution can be a proxy for opposition to transit investment, with a veneer that says otherwise. Which means that the support for the integrity of a BRT system may be limited.)
Rail vehicles are more spacious, which influences ride perception and not just capacity.
Are you sure you really want to make your discussion about tweaking the “rail is better than bus” story? That’s the undercurrent I see, and maybe your ends might be better served if you’re less defensive and don’t give rail that assumed advantage.
There’s always the perennial question of why there are any cultural differences in the first place, and you don’t address that. Taking some of the features of rail and trying to replicate them in bus systems is relatively new, and that may be part of the answer.
@Patrick Moore: With longer-distance commutes, urban route-bus stock would be inappropriate. But long-distance buses, such as those used on the successful BoltBus on the BosWash corridor (is that enough camel-case for the day?), may be suitable.
I think you’re understating some of the inherent differences, Jarrett. For example: fuel efficiency on a modern DMU is much higher than on a modern bus. A FLIRT gets about the same fuel economy as a hybrid 40′ bus, but has twice the weight and capacity.
Another difference is that trains can run with much higher MDBF than buses. A good bus has an MDBF of 15,000-20,000 km; for a good train, make it 500,000. Especially if your commute is long, it can make the difference between one critical failure per passenger per year and two per lifetime.
A different issue, more cultural than technical but still pretty much immutable, is different regulatory environments. North American mainline rail regulations are terrible, but at least there are laws giving priority at all grade crossings, helping make trains a little more reliable all else being equal.
Uh, now that I reread the article, I see where the 36 came from. 🙂 (And quite a few of them aren’t worth considering).
1. “On the other hand, busways can often eliminate extra
connections because buses can run through the busway but then flow out
onto ordinary streets.”
I this ‘advantage’ might be way oversold. You can get a very similar effect by running BRT to the rail station. Perth runs buses to the station, Toronto does it, Calgary and Edmonton. And as I understand it, they all recorded increases in patronage, not decreases, even with the added need of a transfer.
The main thing is access to the station, less so the lack of transfer I feel. Lack of transfer is “nice to have” but not essential. On a closed BRT system, you have to transfer anyway so it can’t be “intrinsic” difference. See (3)
Yes, but one could argue that huge amounts of care are taken with regard
to routing trains for this very reason. And if you run BRT out of the train station you have all the flexibility of bus.
3. Rail is better suited to long-/medium-distance commuting How many people will commute 40-60 km on a bus? Not many.
Disagree. Rail comes in many forms: Light Rail, Streetcar and Metro rail. They are all rail services that you can run at short distances around the city. Melbourne is a working example of this.
Bus vs Rail may be interesting to cities thinking about building a rapid transit system which don’t have one now (e.g. Canberra). However such a debate is far less helpful for, many cities like Brisbane which have extensive existing rail infrastructure that really needs fixing up.
I only wish they fixed up the frequency and started running BRT frequent buses to the existing train stations that Brisbane has. Our Brisbane rail service is so neglected it is not funny anymore, indeed it is an embarrassment when you draw up a 15 minute frequent mapping only to find most of the rail network is invisible on it!
Don’t get me wrong, our two main busways are great, but we have many more train lines and train stations than busways. They need some some reform too, and it wouldn’t make sense to construct parallel busways to them no matter how good bus was.
‘Obviously, those two systems are different for many reasons other than the rail-bus difference. But it’s easy to assume that the rail-bus difference necessarily implies all the differences that you experience between your own rail and bus options where you live.’
In your position I would phrase this differently. If something is ‘obvious’ you shouldn’t then go on to say it’s ‘easy to assume’ the opposite.
Also, you refer to 36 raised points, but only address some of them. This is probably okay if you really link to the infrastructuralist article right in the text, but otherwise you should refer to all the non-intrinsic points, or at least state what rubric you use for ignoring some of them.
‘However, there is a small range of differences that arise from the physics of steel-on-steel vs tire-on-road operation, and that favor the former.’ – should be ‘there are a small range of’, ‘and these favour the former’
‘It is not an issue where the proposal is to reallocate existing roadspace from cars to transit,’ This can be disputed – e.g. where a bus lane is created by one government it can later be removed quite straightforwardly by another. Essentially, a statement placing value on how expensive it would later be to re-purpose the facility from transit to private vehicles. My thoughts on this are not well-formed, however.
There is one thing missing from the intrinsic bus/rail differences. Rail can be automated. I have yet to see an automated bus in popular use.
This is not a minor thing either. Automation could mean lower labour costs as per your Vancouver SkyTrain post, allowing you to run high frequency services, even in peak hour, at minimal cost with minimal labour and also have an expanded scope of frequency and hours.
Coupled with running BRT out of the train station, such a setup would be quite efficient I would think.
With regard to Patrick Moore’s remarks on cultural views on rail vs. bus, there are bus models available from Corgi and the St. Petersburg Tram Collection. There is the Museum of Bus Transportation in Hershey, PA and Pacific Bus Museum (pacbus.org), an online bus museum with periodic bus excursions. The Nor-Cal Bus Fans also hold bus excursions. However, there is a place for buses and a place for rail in the transit spectrum. It is not all bus or all rail.
google “train museum” (http://www.google.com/search?q=train+museum) 60,400,000 results
google “bus museum” (http://www.google.com/search?q=bus+museum) 8,700,000 results.
google “train model” ( http://www.google.com/search?q=train+model ) 236,000,000 results
google “bus model” ( http://www.google.com/search?q=bus+model ) 193,000,000 results
I have never met a bus fanatic. Train Fanatics lots.
Never seen a magazine devoted to bus model. Train model lots.
1 or 2 exceptions doesn’t disprove the general trend that trains are more popular as a devotion/hobby.
“However, there is a place for buses and a place for rail in the transit spectrum. It is not all bus or all rail.” — I am not talking about “objective utility” I am talking about emotional appeal and values with make objective reality.
As the original post indicates cultural perception “warps” the results and makes it the truth.
My statement is that this cultural bias shows no signs of going away in the 100 years or so since busses came on to the scene. Busses have no emotional appeal. They can’t be sleek and fast like a Shinkansen. They can’t make satisfying noises like a steam locomotive.
Show me a movie like “Polar Express” for busses. Maybe it exists, but then I can come up with a dozen more where trains occupied a central role.
Its easy to say that this is “just cultural” but it seems to be worldwide and persistent. To me that pretty much elevates the rail bias (which drives real outcomes) to the level of hard/cold physics.
Another example of how this plays into real outcomes. A new college mechanical engineers / EEs has a choice on working on the next gen VHSR train or the next sleek bus. Which one has the best possibility of attracting the opposite sex?
Anyone involved in politics knows that people pick their facts to support their values.
(And yes I am “guilty” of exactly this. I will take a train over a bus any day of the week).
Yes, but one could argue that huge amounts of care are taken with regard
to routing trains for this very reason. And if you run BRT out of the train station you have all the flexibility of bus.”
LOL, You haven’t been to the U.S. recently have you? Man, we are nothing but f*ckups when it comes to routing trains. There is a reason the US is a disaster when it comes to rail travel.
I hope australia is better but the US sucks when it comes to rail routing.
@Brent Palmer —
sure you can make busses very comfortable. Google runs their own private bus system with great seats and wifi. But expensive and not normal. More suitable for private buses and higher prices.
@ Patrick Moore
We have a train system that is quite old, built a long time ago, however it is only recently we have started thinking about fixing the rail system. Our busways are designed to complement the rail system by “filling in the gaps”, so while we have a North, South East and Eastern Busway, Brisbane has no Western Busway precisely because we have a train line out that way.
So it’s only half an argument picking modes, many cities will find that they have to work with what they already have, so the debate becomes instantly less relevant for them.
I disagree about your inflexibility point- it depends. As a rule of thumb, the closer BRT imitates rail, the closer the costs and inflexibilities approach that of rail. Indeed at higher passenger volumes, BRT may need to convert to a feeder-and-trunk model “closed BRT” involving transfers, so it becomes more like rail in that regard.
Our busway costs per kilometre are around 100 million per km and higher to construct, which is comparable to that of heavy rail lines. The reason for these high costs isn’t because “its busway” or “its railway” the reason is it is Class A right of way and the actual acquisition of land, construction works, bridges and tunnel are costly, and will always be costly no matter what vehicle or mode you choose.
The stations along the high-end South East busway are made of solid concrete, glass and steel, if you get the routing of that main busway corridor wrong, it is going to be arguably just as bad as a badly routed rail service, and as painful to change as a badly routed rail corridor. I think this is more of an argument to have competent planners and designers of the corridors than it is a modal choice argument.
And that’s because both rail lines and high end busway corridors are what Vukan Vuchic calls “Class A right of way”. Sure you could route buses off the corridor perhaps, but that causes a reduction in speed because you are now running on boring old streets in mixed traffic. Why not just get the routing correct in the first place? Or if things change, alter the route of the feeder bus leaving the train station?
I think the “inconvenience of transfer” might be a cultural thing, so long as you have a frequent trunk and connecting service, people will get used to the idea of transferring and it will become second nature.
On the following point, while I can’t disagree, I do wonder if you’re drawing the right conclusion: “History clearly shows that rail systems do stop running if their market disappears. True permanence lies in the permanence of the market, and that lies in the pattern of development, as we’ll explore in the next chapter.”
Technically you’re right, but in most juristictions the speed at which the change is achieved is much slower for rail. For instance the closure of the Manchester tram took 15 years. The closure of substantial parts of the British Rail network in the 1960s required acts of parliament and gave time for negotiation and saving some routes. In contrast my local bus route has changed 3 times in the last few months and others have been removed with no consultation. Neither is truly permanent, but if I find out my railway station is closing in a year it gives me time to consider my options; if I wake up one day and there’s a sign on my bus totem saying that the service finishes running on Friday I’m stuck.
Now as you say this is a regulatory issue, and there’s no intrinsic reason why buses and rail based systems should be regulated differently, but they are and in the time scales that a system will be funded and built in those regulatory levers are very unlikely to change.
@ Patrick Moore – Re : Bus Models
I think you need to take a look at Interlego AG of Denmark. They’ve done an assortment of vehicles, road and rail, over the years. Their London Omnibus model was quite popular when it was available.
Bus movies ? How about “Speed” (IMDB.com entry) ? There’s plenty more where that came from : http://www.imdb.com/find?s=kw&q=bus (IMDB.com search results).
“History clearly shows that rail systems do stop running if their market disappears. True permanence lies in the permanence of the market, and that lies in the pattern of development, as we’ll explore in the next chapter.”
Or if their market is made to disappear by those intent on car-first policies which construct freeways, build high levels of free parking in the CBD, cut service frequency (one of the most crucial things for high patronage), cut traffic priority measures, roll back service scope of hours and destroy high quality transit systems like many tram and trolleybus systems in the 1950s-1970s.
I don’t think urban patterns of development are the whole story. Far from it actually.
I’d just like to reply to one of your statements at the very beginning:
But it’s easy to assume that the rail-bus difference necessarily implies all the differences that you experience between your own rail and bus options where you live.
The rail-bus/BRT argument is often waged in cities that have no rail service, but where rail service is being proposed. I’d argue therefore that people are comparing their own city’s bus service with other cities’ rail service — and, more to the point, have in mind iconic rail systems like New York or Portland. The difference is that those cities often have high existing investment in transit generally, which may mean that the smallish starter line that emerges from the planning process in the new city will inevitably disappoint.
Perhaps someone else has already mentioned this, but an additional issue to consider is maintenance. Similar to breakdowns within the railway: the need for maintenance necessitates either single-tracking (assuming a second track is available) or truncating service. …And if running rail service along curb lanes rather than median lanes: running a contraflow rail vehicle in shared traffic is likely to be a poor choice.
Our busway has maintainence too.
Sometimes when resurfacing works need to take place there might be single lane and people out with signs directing buses at this point. The same thing can happen with construction works such as adding portals and so on.
So no difference at the high end- if its just like rail, its just like rail- warts and all.
An added factor to Maneuverability around obstacles, special events (parades, demonstrations, etc.) and construction that occur in the corridors otherwise used by transit. Fixed guideways systems would typically become dependent upon bus bridges between station stops, while flexible modes could deviate to adjacent corridors and temporary loading zones under such circumstances.
“Is the smooth ride of rail indispensible to a useful network? This can be a tough question whose answer may vary from one community to another.”
Jarrett, I hope that this question will be discussed in detail in your book. This bullet point feels entirely unsatisfactory to me without significantly more elaboration.
This post is very clear and I can’t argue with any of it. It goes a long way toward convincing me that in many cities with medium density (say, less than San Francisco, but more than Omaha), converting part of the existing roadway to physically-separated busways would be the most effective way of improving mobility.
I suppose that later on you’ll argue that many cities don’t have (and will not in the forseeable future have) enough density to require the capacity provided by rail. Actually every city that does have the density for rail also has sections without that density. I would argue that they should fix their zoning laws, but I suppose there is a middle path.
You touch on the political issue of why supporters of more investment for cars seem to turn into bus fans whenever transit comes up, but I think it deserves about 100x as much attention, since in the US, at least, these systems are used as trojan horses to destroy rail (because the ‘road warriors’ know deep in their heart that a rail line which attracts choice commuters will lead middle-class voters to support expansions of the transit system in a way buses never will and never can).
How do metro systems that run on rubber tires fit into this hierarchy. Are they still considered rail, or just a lot of buses linked together to form a train on a different kind of track?
On “Perceptions of permanence”, I think there is an intrinsic distinction between buses and trams.
Yes, entire rail lines can be eliminated, as in the sad case of Los Angeles, and even many lines in San Francisco have been. However they have been replaced with buses running in proximity to the old rail line. Subsequently those lines have morphed into something barely recognizable to anyone who rode the original rail line. The reason for that is that bus lines don’t normally disappear, they get modified a little by little to fit new development and ridership patterns. However, rail lines typically don’t have this flexibility so typically they drive development and ridership patterns instead. The flexibility of a bus can be viewed as an advantage – higher efficiency since you track demand, but the need to track demand comes from the expectation on developers’ and riders’ mind that buses will be flexible.
One point of interest that I don’t think has been directly mentioned yet is the idea of value capture. In the US we are facing a transportation re-authorization that, due to the new political landscape will potentially decrease transit investment significantly (if one is to believe these rumors floating around). I believe that in the future we will see (at least in the US) an increase in the use of value capture mechanisms (TIFs, SSAs, BIDs, etc) to support transit investment and expansion.
My question is this, which mode creates more economic value for which to be captured and invested into the system? Poor wording, I know, but I am running late this morning. I know a lot has been written on the subject, at least in regards to Brazilian BRT systems. Unfortunately, I am not up on my literature review.
While perceptions of permanence are rightly ascribed to cultural factors, these same cultural factors influence investment, politics, etc. Debating the intrinsic characteristics is one thing but money is influenced by the cultural arena. If value capture will be used significantly in the future we must know what creates value. This, however, becomes more of a cultural questions than a technological question.
Sorry, my thoughts on this are still forming (and all over the place). and while i agree (thanks to this blog) that buses can largely duplicate the perceived amenities of rail systems, i also believe that political and cultural realities are more important. anyway, late for class.
@ Ted King —
Look at the macro-level not a a data point thats why I used the gross metric of google search counts.
@In Brisbane —
Sadly, in the U.S. I have rarely seen a competently designed rail system. Even back in the 1900-1920 heyday of streetcar building, streetcar routes were built out into the countryside as a way to fuel land speculation and new home development. Today, the US builds unnecessary roads in the early 20th c. we built street car lines. The LA red car was exactly that. If this blog existed in 1910 it would be talking about the stupid LA red car lines. Of course, LA grew out and up around the new lines so the lines looked great later.
So as much as I like rail I always assume that the politicians are going to muck it up. In the U.S., its helpful if a transit engineer has no pride because what they get to create is crap compared to what I am sure they know is the best. I can list out 4 projects with in my local area ( very expensive projects) that are being built crappy.
Flexible routing of busses
My comment about rerouting buses should be in the context of street running not some sort of high-end busway.
Why I personally would never support a busway
The major problem with busways is that it takes very little for a busway to be converted to car usage.
The arguments go like this,
“An exclusive busway
So in a blink of an eye that exclusive busway is compromised during the building process, quietly, without public comment, and in a perfectly “reasonable” way. The decision is made during building to accept a staff recommendation that to cut costs to keep the project in budget. By a 5-0 vote on the consent calendar the supervising board passes the recommendation. Maybe if a transit person happens to be following the posted agenda, it gets pulled off the consent calendar. A few words of regret are mumbled. Maybe the item gets deferred to next meeting. staff comes back with “its the only way” and the 5-0 vote happens next month. But it still happens. Transit advocates do not have access to the modeling software, data, and time to provide a different recommendation. All they can do is talk about “belief and knowledge” which may be correct but not persuasive especially when the governing board does not want to be persuaded. Many times the members on a transit board are appointed and not directly elected, so they are very willing to go along with staff recommendations because it is easy, they are lazy, and they have other things they want to do.
So that exclusive, grade-separated busway becomes an extra lane on a freeway. During the next major freeway construction project, car traffic is “temporarily” (for 5 years) routed into the “exclusive” busway.
The transit advocates do not have the ability to prevent such changes during the building of an exclusive busway. Transit advocates only have power when there are only a few people paying attention. Once the cement trucks start rolling the construction firms/labor unions are more than willing to take change requests. A busway has to be constantly defended.
At least that is how good transit is built (destroyed) in the U.S.
A rail line cannot be so easily repurposed and is more easily defended.
This is a great contribution to reasonable decision making. But to be picky I think you are using ‘capacity’ in a confusing way – particularly if the book will be applied in countries with low labour costs:
“Capacity. Where demand is high, rail can serve that demand at a higher ratio of passengers to on-board staff”
I think it would be much clearer titled ‘labor costs’, this is something that varies a lot country to country:
‘Labour Costs. Where demand is high, rail can serve that demand at a higher ratio of passengers to on-board staff’
But that is a picky point,
Thank you! This will be a useful reference as is.
Changed my mind, now I think “Vehicle Capacity. Where demand is high, rail can serve that demand at a higher ratio of passengers to on-board staff”
would be even clearer.
“I have never met a bus fanatic.”
Then you’ve never had the “privilege” of seeing the misguided and misnamed Bus Riders “Union” in Los Angeles in action, which has thankfully declined in both influence and credibility.
Two inherent differences between rail vs. bus technology:
1. Top speed: rail can be operated safely at higher speeds than buses, even if both are on exclusive rights-of-way with no grade crossings.
2. Acceleration: although this is more a function of the type of propulsion (which would be a misidentification), the reduced friction of steel on steel vs. tires on asphalt also gives rail an acceleration advantage.
Very interesting post. I do transit research at a community college and it’s fascinating to hear people’s explicit and implicit assumptions about various modes of transportation. The cultural associations of bus vs. rail are incredibly powerful, which especially comes to light in my own work when asking people why they feel the bus is unsafe or dangerous vs. populations who regularly take trains.
Separating the intrinsic differences between bus and rail and pointing out where arguments for one mode versus another might be flawed is definitely an important discussion to have. That said, while many of the 36 advantages of streetcars may not be intrinsic in principle, that doesn’t mean they’re invalid. Social and political forces have polarized the various advantages and disadvantages of each transit mode, and to say that something CAN be achieved by a particular mode doesn’t mean it WILL be.
@ Patrick Moore
“The major problem with busways is that it takes very little for a busway to be converted to car usage.”
In Brisbane, some have tried to suggest using the Eleanor Schonell Green Bridge to run cars on it. And this is high-end busway. I’m just glad the bridge was designed to be anti-car and impossible to expand.
I regularly see some cars stray into the busway. To be fair, we also have a chronic problem on rail too with drivers smashing into boom gates almost weekly, as they try to beat the lights.
So there is no perfect world. That said, I don’t believe either of these 2 problems is so significant to warrant changing a decision on modal choice. (And I would say the same about the bus driving around obstacles vs Tram, use the horn! BEEP BEEP!).
I’m not sure why rail seems so controversial in the US, it seems to attract have the same level of reaction as someone proposing to build a nuclear power plant or something.
BRT are valid choices and they can work well, while you wait for something bigger, and can even be complimentary to rail if you choose to operate it out of the train station.
And that’s my main criticism of the Bus vs Rail debate. Every city will have different corridors with different needs and thus modal requirements. Even in Brisbane this is true.
Nobody would advocate running buses in the Brisbane River, or thinks that our CityCat ferries are “too inflexible” because they are limited to the river. We don’t hear about bus vs Bicycles or walking for instance, and decide that bicycles or walking are too slow for ‘real’ transport solutions and that therefore no footpaths or bike lanes will be built in the city.
So the answer really is ‘it depends’.
Here is the post: http://www.brisbanetimes.com.au/queensland/open-green-bridge-to-traffic-councillor-20100929-15x9a.html
First, thanks for bringing up trolleybuses, as the issue of propulsion is largely orthogonal to rails vs. road. I wish more agencies would consider trolleybuses as an alternative to both buses and light rail. Their superior acceleration can help push the stop spacing/average speed tradeoff curve higher so that you can have a bit of both.
I do however have couple of technical points: rail does tend to be louder on curves, but tire-on-road tends to be louder at speed. So which one is louder overall depends on where you measure and what the alignment looks like. Also, I don’t think the maneuverability argument is not as strong as you make it out to be. Because buses can move out of the way, it’s expected that they will move out of the way, and indeed the overwhelming majority of bus stops in the US are set up so that the bus pulls out of traffic to the stop, and has to wait to merge back into traffic. Of course, bus stops could also be set up with a bulb-out that extends the curb to the lane that the bus is in, but these are used fairly rarely. And, importantly, streetcars are almost never set up such that they have to pull into traffic from a stop. While the delay at any given stop is small, these small delays tend to add up over the course of a long bus route running on a busy arterial. And of course if you have narrow streets, then the bus could get stuck just as easily as the streetcar, and it’s rather less likely that there will be severe consequences for the cause of the blockage.
I was just reminded by Jarrett that my comment was unclear, in that I talked about the FLIRT, usually an electric train. There’s a diesel version, which gets about 4-5 mpg, same as a hybrid bus.
Trolleybuses are an interesting technology, and they definitely have their place. Hilly cities for one are perfect for trolleybuses since their traction motors generate a lot of torque to get going uphill, and with rubber tires they’re less likely than a streetcar to slip. Trolleybuses are also much quieter than diesel buses, especially inside, and don’t pollute where they run, but at that point the advantages evaporate.
Trolleybuses are still subject to the jostling and poor road conditions that diesel buses are, and they tend to be treated just like other regular buses as far as stops and right-of-way are concerned. While they may be able to accelerate better, I don’t see it as really being all that big a deal. I’ve ridden CTA buses in Chicago, and new and old Metro buses here in Cincinnati, and they accelerate just fine. In fact, I’m kind of surprised they accelerate as fast as they do, as that can really throw passengers around who are trying to get to their seat.
The overhead wiring for trolleybuses is the elephant in the room with them though. It’s much uglier and more complicated than it is for streetcars with a pantograph. When aesthetics come in to play, which they certainly will as it’s something the naysayers can rally behind, they always bring up the overhead wiring. It’s easy to minimize it with single overhead streetcar wire, but dual overhead for trolleybuses is a much tougher sell.
The other thing with trolleybuses is that how different is the cost really compared to light rail? Would the gap be so narrow that it might not matter over the lifecycle (capital costs + operating costs?)
I expect that you would have to buy large, expensive, ugly electrical transformers for power supply and I am assuming that is very expensive so you are paying more by not getting the ride quality, or capacity of LRT. On the other hand you may not need to dig up the street like LRT might require.
^^ ‘by’ should be ‘but’. Typo!
Is the ability to operate or keep a schedule in snow and ice an intrinsic advantage for rail? This has been my experience, but I do not know of any studies that measure that. And even if it’s true, it only matters on a certain number of days a year in most places. But I hope you can address this or debunk it.
I also hope that your book will include a nice set of appendices or end notes to cover some items in more detail or be more exhaustive than you want to be in the main text. It would be shame to lose some the great material you’ve gathered just because it cannot all fit without bogging down the reader.
Regarding trolley buses and power supply: They use the same power supply that streetcars and light rail trains use; in San Francisco, portions of the Market Street overhead are used by both the streetcars and the trolley buses. The power is 600 volts DC, which comes from substations with transformers, rectifier banks and auxiliary equipment. The substations can be in underground vaults or in unobtrusive buildings. Some of the early day subs were in large brick buildings that one writer termed “temples of electricity”, but most of the newer ones are small, standardized structures that can be hidden behind walls or bushes. Another item about San Francisco: all the electricity that runs the rail and electric bus transit comes from a city-owned hydroelectric plant; even the big motors that power the cable car machinery run on (ultimately) water power. The San Diego light rail system gets much of its “juice” from the San Onofre nuclear plant.
you say that buses have little cultural significance, well, I can think of four movies where a bus played an important part:
1) Speed (Kenau Reeves and Sandra Bullock save passengers from a bomb hidden aboard a transit bus.)
2) Bus Stop (Marilyn Monroe is an aspiring actress headed toward Hollywood on a bus before running into a lovesick cowboy and getting snowbound at a bus station.)
3) It Happened One Night (Claudette Colbert is a runaway heiress who buys a ticket on a long distance bus only to run into savvy reporter Clark Gable.)
4) The Big Bus (This parody of disaster movies is about an oversize bus that travels from New York to Denver with hilarious problems.)
@ Dan W-
@ Dexter Wong –
spend the time to understand the point I was making (repeatedly).
Trolleybuses do accelerate better than diesel buses, and can actually match a car’s acceleration. What throws passengers around is not generally acceleration but the change in acceleration, or jerk. Trolleybuses have an advantage there in that they don’t have to shift gears (they’re fixed-gear, so no clutch either), which reduces a bit of jerk. The wires are definitely a problem, and since there’s two of them, they’re more intrusive than those for light rail, especially at junctions. The power supply equipment for trolleybuses tends to fit easily in underground vaults or fairly compact enclosures on the surface, and the power supply equipment isn’t terribly expensive either. Interestingly, studies have shown that maintenance costs of a trolleybus fleet plus wires are actually cheaper than for a fleet of diesel buses.
Jeffrey hinted at it earlier, but an important technical difference is that of ability to climb grades. This can make BRT cheaper than heavy rail, and steep grades can limit some light or heavy rail proposed corridors.
Now, if busses came with throttles instead of accelerator pedals, would drivers be less likely to jerk passengers around by stepping on it?
@Mike, old streetcars are quite capable of some pretty heavy grades, with 10% being a typical upper limit, though Pittsburgh had a 12% grade on one line. At that point, your typical diesel bus is probably struggling along at 15 mph with a mighty roar. Trolleybuses do a bit better and are obviously quieter, though they too have their limits (which you can observe on the Noe Valley section of the 24 line in San Francisco). On the downhill side, trams with track brakes seem safer in bad weather than anything relying purely on wheels to stop. And if you absolutely must run something up a 20% grade, there are always rack railways, with rolling stock available that can run both with a rack and without one, achieving a pretty decent speed in the latter case.
I was the one, Jarrett, that originally offered on the Infrastructurist points #33, the different attention paid to stop infrastructure, and #34 the quality of the rails to lend a difference in “City Imageability” (note, by this I meant a different notion than “legibility”). I called #34 the “Kevin Lynch Argument”, since the tracks are present in the fronted street as a feature of the public realm (or, alternatively, they help delineate strong boundaries, as opposed to say, in downtown Toronto, where the streetcar is associated with the liminal border between residential streets, and is a perfect example of the streetcar infrastructure enhancing imageability of urban form. As a reference, I have Lynch’s general discussion on “Paths” and “Edges” in his book, Image of the City.
That clarification said… Reading this blog has dramatically transformed my notion on both points. In fact, I am now more attuned to the exciting potential of frequent service, dedicated lane bus systems. I realize a can of paint can’t do exactly what tracks and overhead wires do, but the “imageability” of the city with this transit amenity, via experience and designed phenomena, is a more fantastic design challenge for an urban designer to tackle. In short, you’ve opened up my horizons.
IN FACT, you have exposed my 2009 “cultural feedback” bias to infer that things like “infrastructure” (alas, I’m a streetscape designer!) figured all that importantly in Lynch’s attention to what actually formulated a citizen’s perception of his or her environment. I was taking Lynch into territory where he actually didn’t go.
This probably goes into the “Limited energy-efficiency and emissions consequences” point, where you touched on the steel-on-steel vs tire-on-road issue but I say you didn’t go into much detail about.
Mainly, steel is highly recyclable compared to rubber or asphalt, and (to my understanding) lasts far longer with comparable maintainence. Tires also bring a fair number of problems – while in use, tires wear down and the particles that come off (“Tire Dust”) cause pollution problems. After use, tires are difficult to dispose of – you’ve heard of tire fires, but other solutions like tire reefs (creating ocean reefs out of tires) have proven to be disasters.
Other than that point though, I’d say this is a very fair and balanced view of the rail vs. bus debate.
@ Bob Davis – Re : “temples of electricity”
I believe that SFMuni has an example of one as part of the old yard at San Jose Ave. and Geneva Ave. If you’re trying to find a StreetView image of it start with the Balboa Park BART Stn. and scan to the Southeast. The links below have images and other information.
Address – Geneva Car Barn, 2301 San Jose Ave., 94112
“An important technical difference is that of ability to climb grades. This can make BRT cheaper than heavy rail, and steep grades can limit some light or heavy rail proposed corridors.”
It depends- our ‘high-end’ busways are designed to be Light Rail convertible in the future, and as a result of that, our busways have been built to LRT curves and grades, so the cost to acquire and prepare the right-of-way is more or less similar I would think.
(As a happy co-incidence of this, I think building BRT to LRT standards results in a noticeable increase in comfort over a standard bus too).
The answer is it depends. Brisbane is building a rail tunnel under the river. To tunnel with BRT under the river would probably allow it to be steeper and perhaps cheaper (tunnels are hugely costly, no matter what mode you want), however heavy rail is the mode chosen simply due to capacity and fit-for-purpose (the train needs to travel 80km to the terminal station, so you would not prefer bus for that).
And then of course you have rail modes such as metro, Vancouver sky train and rubber-tyred metro, which have much increased capacity to climb grades and take curves.
I’d like to add that some of the advantages are not intrinsic to rail, but they are intrinsic to higher investment on your infrastructure. Things like level boarding, good schedules, count-down clocks, grade separation.
And rail is intrinsically the better choice when spending more on infrastructure – it’s expensive, but can move more people more efficiently in terms of cost.
So there is clearly a correlation between the more expensive rail, and the amenities and secondary infrastructure put in place for it.
If you take a bus stuck on a congested street and place that same bus into Class A right-of-way, suddenly you have a high quality BRT service like Brisbane’s busway.
If you take a streetcar stuck on a congested street and place that same streetcar into a Class A right-of-way, suddenly you have a high quality LRT or Light Metro service.
If you take a car stuck on a congested
street and place that same car into a Class A right-of-way, suddenly you have a high quality
freeway or motorway.
In all cases, both capital construction costs and service quality correlate more with the Class of Right of Way the vehicle is running in, and not necessarily the vehicle itself.
This is why I don’t agree with the “bus is always cheaper than rail” notions that seem to be going around. One has to look at the context, and context cannot be ignored.
@In Brisbane, it’s actually not quite as great as you say. If you take any typical city bus from any congested city street and put it on a Class A right of way, it’ll be going 50 mph. If you take a Portland Streetcar and put it on a Class A right of way, it would still only have a top speed of 30 mph. In fact, I think I read somewhere that the Streetcars have to be trucked to the light rail maintenance facility, despite having a connection between the two systems, because the streetcars are just too slow to run on the light rail system while light rail service is running.
These sorts of limitations are the big reason why I think the Portland model of streetcar is not a good one to emulate.
@ anonymouse, my point was that the quality really has a lot to do with the right of way. That’s how BRT and LRT evolved from boring old buses and boring old streetcar systems on streets in mixed traffic (Class C right of way).
It is a big difference because now cars and their congestion are out of the way. People realised that if they separated the transit vehicles from traffic, wider stop spacing and so on, they wouldn’t get stuck in congestion and would be faster and cheaper to run.
Maybe there are some inherently slow buses and trams in the world.
However, apparently the Toronto CLRV streetcars are capable of 100km/hour, so if I replaced “Portland Streetcar” with a TTC one, maybe there would be a big difference. Stop spacing influences speed too if you have closer stops, it is going to be slower, if you have wider stop spacing it will be faster.
@Brisbane – are you sure that isn’t an urban legend? The TTC streetcars’ avg. speed is, if I’m not mistaken, 17-20km/hr. If Toronto streetcars are capable of 100km/hour then why does it take me over 1 hour on the 501 streetcar to cover the straightline distance I could drive in 15 minutes?
I think if a TTC streetcar ever approached anything like 100km/hr time would start to reverse, and we would create a black hole.
Read carefully. No, because cars get in the way and you have at-grade signalled intersections and reasonably closely spaced stops. So even if you had a bus or a streetcar with a jet engine on it capable of aircraft speeds, if you are running in mixed traffic, the fastest you can go is like you said ~ 17-20km/hour.
@ anonymouse – Re : Portland streetcar
The problem may be that the overhead power is incompatible due to voltage or cable gauge. SFMuni has no problem running a mixture of Bredas (LRV’s), PCC’s, Milanos, etc. on the Church / San Jose trackage. Speed is NOT an issue. I suspect that a PCC could outrun a Breda due to the governor that is installed in a Breda car. I’ve heard that part of the overhaul of S.F.’s various historic streetcars has been to make their motors compatible with the SFMuni’s 600 VDC power. Also, SFMuni has retained at least one old-timer for use as a crew + tow vehicle even though most of the PCC’s have a tow bar in a scabbard at the rear.
The blog post says,
“Capacity. Where demand is high, rail can serve that demand at a higher ratio of passengers to on-board staff, which means that once you absorb the (often large) construction cost, you will be able to offer greater capacity for a given operating cost.”
This is false, at least for light rail and probably commuter rail. Only subways have an inherently higher capacity than buses on busways — and not much higher. Yes, buses have a lower ratio of passengers to on-board staff, but that is no the same thing as capacity. Nor, once you count the high cost of maintenance of the capital investment, are bus operating costs per unit of capacity greater.
The reason why rail capacities are lower is the need to separate trains or railcars by two or more minutes, whereas buses can operate several per minute. Do the math: light rail has a capacity of about 10,000 to 15,000 people per hour; commuter trains perhaps 20,000 people per hour; while buses on busways can move 40,000 people per hour.
Jarrett, an interesting article and also some very interesting responses. I think your approach in trying to identify the real “uniqueness” of bus and rail technology is important but I don’t think can be completely divorced from the nature of the corridors and services involved.
This is especially true at the “extremes”. For example, to provide a small, localised transport service in low density outer-suburban or rural areas (either on demand or on a scheduled basis), bus technology using existing roads is clearly the only answer because of its low cost and flexibility. Nobody would contemplate using any form of rail technology for something like this.
At the other end of the scale would be high speed and/or high frequency and high capacity services in dedicated and completely grade-separated corridors such as high-speed suburban and interurban rail services or underground metros. Even if all the “non-intrinsic” differences were eliminated, bus technology would simply not be able to offer the same level of service in these situations for a number of reasons.
An example is the Perth-Mandurah high-speed suburban rail line in WA, where buses would be unlikely to be able to offer the same fast travel times even if they had a dedicated corridor (in this context, maximum speed is probably another intrinsic difference between the two technologies, though it has to be acknowledged that for many transport corridors this probably isn’t a significant issue).
In the case of metros, if you were to take buses as your starting point, eliminated the non-intrinsic differences and minimised the intrinsic ones in order to meet the demands of providing a high-capacity, underground service, you would have to add electric traction, vehicle guidance, automated signalling systems, multiple trailers, platform loading etc, etc. The result would then be virtually indistinguishable from rail technology, apart from running on rubber tyres, so it would end up looking pretty much like the tyre-based Paris metro lines – and probably cost about the same as metal rail technology anyway.
In fact I see that the Infrastructurist article you have used as your inspiration talks mainly about the differences between streetcars and buses, not rail versus road-based transport generally. The points you raise are also most relevant when applied to street-running bus services and trams, or further up the foodchain, busways and dedicated light rail corridors. In both cases there is much more overlap between bus and rail-based services.
There are a few other issues worth noting here, however. Generally speaking, bus technology has to be more fully “optioned-up” from its base form than rail to eliminate the non-intrinsic factors and mitigate the others. Ride quality is a good example. Basic trams running on well-maintained tracks in mixed-flow situations will usually offer a better ride than buses in a similar situation.
It is only in dedicated corridors that the latter have the potential to approach the standard of the former and even this requires careful planning and additional construction costs – for example, the decision to build the Western Sydney bus transitways to light rail standard to allow for their potential conversion, or the extent to which the Brisbane busways were engineered to improve ride quality.
In some respects it’s a bit like choosing
between a top-of-the-range car with all the extras built in or the basic model and then adding on the extras. Often the latter would end up being more expensive and the technology not as well integrated as the “de-luxe” model. In the case of busways, I understand that the cost of the dedicated busways in Sydney and Brisbane approached that of light rail.
This isn’t necessarily a reason not to build busways if they offer other advantages, but if all the options you mention are added (such as electric traction, vehicle guidance, etc) to mitigate the “non-intrinsic” differences, they could well cost more than light rail. This expense also often results in trade-offs being made in relation to busways, as highlighted in many of the responses to your post.
A couple of other observations. I would add another intrinsic difference – rail, by its nature, has a built-in standardised “guidance system”. While there are differences in rail gauges and other associated technology, and railcar or tram of a given gauge will conform to this basic guidance system. This means it is possible for many tram and light rail systems to purchase vehicles off the shelf or lease them from other systems with little modification.
Of course, basic buses used for ordinary street-running of course have very few compatibility issues, but the situation is much more complex in relation to guided bases. There are at least four different basic technologies (kerb-guided, central rail, optical and electromagnetic) in use and eight or nine incompatible guidance systems based on these technologies. This isn’t to argue against the concept of guided busways, which have a lot of potential, but unless a dominant guidance technology emerges rail should be considered to have an advantage in this area. You simply can’t buy a guided bus off the shelf.
Another interesting area of difference is flexibility and scale. Of course, buses have an advantage that the same vehicles can go very easily from running mixed-flow systems servicing local bus-stops in outer suburban areas to providing dedicated busway services in higher-density corridors.
While trams and light rail can’t match the flexibility of buses at the suburban level, they can be more easily scaled up at the other end. The transport system in Cologne and some other German cities are good examples, where trams can start in outer suburbs with basic on-street services, then run in dedicated corridors as light-rail services in middle-ring suburbs, much like busways – however, they then go underground to provide metro-like high capacity services in the CBD, a feat that would be much more difficult to do with buses.
The reason why rail capacities are lower is the need to separate trains or railcars by two or more minutes, whereas buses can operate several per minute. Do the math: light rail has a capacity of about 10,000 to 15,000 people per hour; commuter trains perhaps 20,000 people per hour; while buses on busways can move 40,000 people per hour.
Randall, this simply isn’t true. Short-train rail systems (1-2 trains) have little problem using signalling mechanisms beyond block signalling, which is subject to the 2-minute (or 108 second) headway limitation. The New Territories light rail system in Hong Kong (not to be confused with the MTR heavy-rail system which operates primarily in downtown and Kowloon) uses streetcar-style signalling, despite operating in its own right of way, permitting very close spacing between trains (with two trains often parked at the same platform, loading independently). It’s the only train system I’ve seen where bunching is occasionally a problem, though must bunching occurs due to the extensive interlining on the system.
The Lincoln Tunnel XBL is cited as an example of a high-capacity busway, but it’s an unusual situation, given that you have a high-capacity bus station (the Port Authority terminal) at one end of the tunnel, and significant fan-out at the other. Use of the “freeway of busses” to achieve high capacity over a long corridor is very difficult to do; especially if you limit yourself to a single lane for the busses to operate in. And given the labor economics, such arrangements don’t make sense in the developed world, where the biggest operating cost is labor.
LRT can do better than 15k/hour, BTW. MAX moves 6k/hour across the Steel Bridge running 2-car trains at 3 minute headways, were it to run longer trains at 2 minute headways it could easily best your 15k estimate. (Other issues having nothing to do with theoretical rail capabilities prevent this in practice). Vancouver SkyTrain (running 4-car trains at 108 second headways) can do about 22kpphpd. And there are many heavy rail systems in operation which run longer trains that SkyTrain’s 4-car consists.
Antiplanner. There are several equally valid concepts of capacity, including corridor throughput, which is what you seem to mean, as well as vehicular capacity.
The sense that matters to me is the ratio of passenger capacity to on-board staff, because this is ultimately what determines how many people per hour an agency can afford to operate.
@ Alex Gooding, I agree with you.
The cost of Brisbane busways are more comparable with that of heavy commuter rail. That said, I think Brisbane going for the Busway was the right choice over LRT in that corridor.
Gold Coast light rail (running in Class B right of way) is something like 35 million/km, well below the per-km cost of Brisbane Busway. However for the higher cost comes higher quality and capacity (Brisbane Busways run in Class A right of way like rail) and also carry volumes of passengers in peak hour comparable to heavy rail. The closer BRT imitates rail, the closer the costs approach that of rail.
The Perth-Mandurah line replaced a median freeway lane direct bus service and actually runs in former freeway busway lanes. It introduced “forced interchange” from what was a direct, transfer-free trip. And contrary to all the anti-interchange and “time penalty” material I have seen elsewhere, trips on this corridor increased massively, not decreased.
This is why I think the direct transfer free trip “advantage” is oversold- what matters is that you get a bus into the station, whether that is a busway station or a train station. And secondly, “dislike of transfer” may also be a cultural feedback effect- as people become accustomed to interchange it becomes second nature and transit agencies build better interchange facilities.
@ Engineer Scotty
I agree. I would not like to see something like the XBL replicated in Brisbane. 615 buses per hour flooding off a busway into city streets will cause huge bus congestion, reduce pedestrian and cycling amenity on city streets and require large amounts of labour (as each bus must have their own driver). That’s something like 5 buses per 30 seconds, and when you consider a traffic light on a city street might take about 30-60 seconds to change, that implies congestion (and also multiple airport-style bus stations on multi story levels to take all those buses).
The capacity of a system is more to do with how it is designed, and the class of right of way and less to do with the vehicle.
For example, a car lane on a freeway might have a “capacity” of 2000 vehicles/hour, and almost all public transport has “capacity” far in excess of this. So you would think that most trips would be taken by public transport? At least in Brisbane, something like 80% of all trips area done in the car. How is this possible? You simply design the road the system to have more lanes. We now have a bridge with 12 lanes (6 in each direction), at 2000 cars/hour/lane, that’s 12 000 cars crossing in one direction, which is the same as light rail or busway.
From the “I don’t get paid by the Kochtopus to be ignorant of real-world transit capabilities” department:
# Maximum PRACTICAL single direction capacity at design capacity of 162 pass./car and 2 min. headway:
3-car train (present) 14,580
4-car train (future) 19,440
# Maximum THEORETICAL single direction capacity (pass./hr/dir) at 256 pass./car and 2 min. headway:
3-car train 23,040
4-car train 30,720
From Calgary Transit, of course, whose downtown segment is in streetcar mode, with signal priority. And without passing sidings at stations. In other words, much lower footprint than Bogota uses for its high capacity.
Here is an eaxample of a UK BRT class B system. Known as ‘Fastrack’ it serves a newly developing area in North Kent Thameside, south of the river Thames, east of London. The system is expanding as the area develops and is currently 40km, with 50% on busway, and 25% on kerb running bus lanes. I would say this is the best example of BRT in the UK to date.
Video showing a trip on the busway – smooth ride quality, and the buses are reasonably quiet.
How about the service life of buses versus streetcars? The Toronto Transit Commission has much on the record that states that the service life of a subway and LRV is 30 years, whereas a bus is 15 years.
Would the comparison be different if the bus was electric?