Human Transit

chicago: a new bus rapid transit plan

A Chicago-area planning nonprofit, the Metropolitan Planning Council, has released a plan for 10 Bus Rapid Transit within the City of Chicago.  The final report is here:  Download BRT TRB Report Final

The work, led by consultant Joshua K. Anderson, is admirably wonky.  It analyzes a huge range of arterial segments to identify those that appear best from a standpoint of both constructibility, demand, and nexus with livability values.  The report is a "screening" study, which means it seeks to narrow the range of possibility and encourage more detailed study of those that remain. 

Bus Rapid Transit is defined quite vigorously:

BRT is 4 defined by four main components: 1) dedicated bus lanes, 2) at-grade boarding, 3) pay-before-you-board stations, and 4) signal-prioritized intersections.

This definition is met by almost none of the things now called BRT in North America, or at least not continuously from one end to the other.  But screening is a time to be ambitious about such things.

The 10 corridors that survive the screening are shown on this map.  They're a mixed bag: portions of segments, some of them maybe too short to be effective as BRT, but also two very long corridors, Western and Ashland Avenues, one of which is probably the most urgent BRT project in the city.

The study appears to be silent on whether these are envisioned as open BRT or closed BRT.  Open BRT means that the infrastructure can be used by bus lines that flow onward beyond it to other destinations.  To take an obvious example, an Irving Park BRT that ends at Ashland, short of the Red Line's connection opportunities and the high density of the lakeshore, is unlikely to be satisfying as a complete corridor.  But if it's an open BRT, usable by buses that continue east, it could well be useful. 

Unfortunately, a presumption of closed BRT, in which buses can't continue beyond the limits of the infrastructure, seems to be implied by the author's decision to discard super-dense Lake Shore Drive from the analysis simply because of the complexity of branching patterns that it requires; this assumption will have to be reconsidered in light of open-BRT best practice.

The study illustrates a common challenge in analyzing large, long transit corridors.  Many of the key issues, including available right of way and "livability" impacts, are segment-by-segment affairs; if these dominated the analysis, the result would be a huge pile of largely disconnected short segments, which could not deliver the intended outcomes.  So the author streamlined, discarding small segments and emphasizing larger continuous ones, which is quite right.

But issues of network integrity and completeness seem not to be fully considered.  The report needed to step much further back and describe the underlying geographic structure of Chicago, which determines the type of services that could be relevant to citywide mobility needs.

Except near the lake, Chicago is an extremely regular grid of arterials spaced 1/2 mile (800m) apart.  CTA follows this grid with a grid-pattern of long bus lines that attempt, as much as possible, to cover the entire length of an arterial all the way across the city.  This achieves the important goal of grid completion.  The purpose of each line is not just travel across that street but to complete a network in which people can travel from literally anywhere to anywhere else through a simple L-shaped movement:

For more on the high-frequency grid principle, see here.  Obviously this structure only works, in its purpose to serve any origin-destination pair, if its constituent lines flow all the way across the grid to its natural edge.  This is the problem with many of the proposed BRT corridors in the report.

Not everyone sees this grid, because Chicago also has an overlying radial system of rapid transit, which runs along diagonals pointing toward downtown.  The two overlaid elements -- radial trains and grid buses -- work well together, but if you focus too much on the trains, which are mostly about going downtown, you miss the power of the underlying grid to complete trips on any origin-destination pair by a reasonably direct path.  (The report discusses "network integration" only in the form of integration with rail.  Confusingly, too, it gives heavy emphasis to connections with suburban commuter rail -- whose poor frequency makes connection difficult -- and little to the bus-bus grid connections that are the essence of the network's anywhere-to-anywhere versatility.)

Given Chicago's grid structure, and how well it already works, BRT needed to be understood as a system of grid accelerators, just like the Metro Rapid and proposed Wilshire subway in the similar grid of Los Angeles.  Obviously, if you can concentrate particularly heavy demand on a few elements of the grid, you can justify an overlay of much faster service, stopping only at the grid connection points every half-mile.

On that score, Western Avenue is clearly a winner.  It is the longest arterial in Chicago, running north-south the entire length of the city.  Its extreme length creates reliability issues on a local-stop service, which has caused CTA to break it into three lines thus reducing its usefulness for continuous movement.  BRT would be an opportunity to recombine these three segments to offer a service that would be understood as an intrinsic feature of Western Avenue over its entire length.   Western is also far enough out of downtown that the direct paths it serves are much faster than riding rail into downtown and back.  A vast range of trips between many parts of Chicago would find a Western BRT line useful. 

None of the other corridors identified in the study can match Western in the utility that arises from extreme length with lots of connection opportunities.  Ashland is obviously close.  Most of the other proposed segments are simply too short, and would be useful only as open BRT segments used by buses that run further.  Effective BRT has to serve long corridors, because the tradeoff that BRT requires of the customer -- walk further in return for faster service -- makes sense only for a fairly long trip. 

To sum up, the report is very useful and highly recommended.  But it misses (or at least downplays) two points that are missing in many similar studies, and that really matter:

• Open or closed BRT?  They're totally different, and if you're not clear which you mean, it's impossible to envision the service patterns, and thus the mobility, that your proposal will offer. 
• Integration with the total network, not just rail.  This requires seeing how the whole mobility flow of the city works, and how each corridor would contribute to that flow.  Localized analysis that asks where BRT would be easy to create or locally beneficial can easily lose this "forest" in its obsession with the trees.  Understanding this principle would have required a much firmer focus on complete corridors that traverse the grid and make many connections, rather than the small fragments that are frequently proposed.

Still, the report can do a lot of good, and bravo to the Metropolitan Planning Council for sponsoring it.  Chicago really needs to start accelerating its bus grid, especially on its busy, high-stakes, versatile corridors like Western.  I hope this study helps to move that along.

 

cambridge, uk: world's longest guided busway opens

From our UK correspondent Peter Brown:

The Cambridgeshire Guided Busway finally opens [today], Sunday 7th August, and at 25km will overtake Adelaide's O-Bahn (on which it was partly based) as the world's longest guided busway.  It will be an 'open' BRT as services will not be restricted solely to the Busway.  The guideway consists of two sections.  The longest runs from the northern edge of Cambridge to St Ives, while the shorter southern section runs from Cambridge rail station to Trumpington.  There are three Park and Ride sites on the route.
 
The buses are standard UK designs (single and double deckers) fitted with guide wheels.  Guideway stops will feature off-bus ticketing.  Guideway stop (prior to opening):

Two bus companies (Stagecoach and local independant Whippet Coaches) have signed a partnership agreement with Cambridgeshire County Council for exclusive use of the Busway for 5  years.  Services will operate under a single brand - "the busway".
 
More info:
 
http://www.busandcoach.com/featurepage.aspx?id=2088&categoryid=5
 
http://en.wikipedia.org/wiki/Cambridgeshire_Guided_Busway

If this busway doesn't turn up significant benefits in customer experience, it will probably be the last, or at least the last to be done with guide-wheels.  Adelaide's pioneering O-Bahn is now 25 years old, so one hopes the state of the art has moved on.  (There's also a guided busway in Nagoya, Japan, dating from 2001, where the government classifies it as a railway.)  All of these, including Cambridge, are open busways, i.e. designed so that buses can run off the ends of the facility onto various street-running lines. 

So I'll be curious to see how this goes.

bus rapid transit: two kinds of flexibility

 

On yesterday's post on the watering-down of Bus Rapid Transit proposals in Bristol, UK, a number of comments seem a little vague about how buses are more "flexible" than rail.  For example, Carl writes:

The two primary justifications for BRT [are]:

1. Like rail but cheaper. ...
2. More flexible. More flexible means it doesn't need exclusive right of way everywhere (usually the chokepoints), that other traffic can use the lanes, etc.

This a very common way of framing the question, and a very misleading one.

First of all, the notion of "flexibility" used in #2 has nothing to do with the bus/rail distinction, at least if we're talking about surface light rail or streetcars.  You can put streetcars or light rail in mixed traffic and get all the same speed and reliability problems that a bus would deliver in the same situation.  So again, in urban transit:  Speed and reliability are not about vehicle technology; they are about what can get in your way.

But Bus Rapid Transit offers a very different flexibility that in certain situations out-competes rail.  A busway can be designed so that buses from many surface lines can flow into it.  This potentially spreads the usefulness of the busway over a large area without requiring an additional trunk-to-feeder connection.  Connections are unavoidable in good networks, but if there are easy opportunities to eliminate one, it's still worth going for.

This ability to flow through to local lines yields what we call an open busway.  North American open busways include the Ottawa busway network, the Pittsburgh busway, and the Los Angeles El Monte Transitway, but they are much more common overseas, including the developed world's most extensive example in Brisbane, Australia.  This kind of flexibility is impossible to do with rail.

Closed busways, which has none of these benefits but can have more "specailized" vehicles, include the Los Angeles Orange Line.

The flexibility of open busways makes sense only where it matches the pattern of the market. Brisbane is a highly radial city, with a single downtown and densities dropping away as you move away from it.  Outlying nodes of high activity, which could be a strong endpoint for a closed busway or rail line, are scarce.  So the open busway makes perfect sense.  It allows busway service to spread out over a larger area, yielding high frequencies on the inner busway where the demand is higher, and correspondingly lower frequency further out.  It's the kind of flexibility that fits the city.

watered-down bus rapid transit: the u.k. edition

We often hear that proper Bus Rapid Transit [BRT] is impossible in the US because any such proposal gets watered down by the defenders of traffic lanes until it's nothing but a fancy bus stuck in traffic.  I don't believe in surrendering to the inevitability of that, but there's no question that it's a political challenge in many cities.  Meanwhile, US readers should be assured that this isn't a particularly US problem.   Our reliable UK correspondent Peter Brown reports:

It would seem that [Bristol's Bus Rapid Transit] scheme has gone from medium to low end BRT due to central government latching on to the ease in which economies can be made by deleting the features that make it rapid - i.e. dedicated busways, and continuous bus lanes.  We are now reduced to short stretches of kerbside bus lanes approaching junctions, but no traffic signal pre-emption.  Where there were going to be median bus lanes, they are now going to be kerb running. 
 
This will make the BRT little different in the eyes of the (already sceptical) public to the separate package of conventional bus corridor improvements branded 'Showcase Bus Routes', several of which have been rolled out over the last few years.  In order to distinguish BRT in the eyes of the public I think the BRT stops are going to have to look much different from standard bus shelters, and the vehicles are going to have to have some eye catching branding, and have hi spec interiors. 
 
It troubles me that much of the BRT busways were to be located in the North Bristol fringe, an area of low density cul-de-sac esatates, out-of-town business and retail parks, all connected by dual carriageway roads and multi-lane roundabouts which cannot handle existing peak hour traffic, and would have made a real statement about better public transport.  There are also plans  for further massive housing development, and new roads that will add to the traffic load and threaten BRT reliability.  This is the latest newsletter that has got me so worried:
 
http://travelplus.org.uk/media/218106/rt%20travelplus%20newsletter%20final.pdf
 
Meanwhile I continue to defend the principles of BRT in the local press web comments!
 
http://www.thisisbristol.co.uk/discussions/Does-think-bendy-bus-plan-abandoned-tram-pursued/discussion-12818823-detail/discussion.html#comment-2459045

Is this problem less likely in continental Europe?  I haven't toured the great BRTs of France, but the Amsterdam Zuidtangent certainly has gaps where, even in the judgment of the transit-loving Dutch, keeping an exclusive lane for the BRT was Just Too Hard.  (I'm not talking just about the narrow streets of Renaissance Haarlem, where the limitations are understandable, but also the quite modern southern suburbia where the line runs.) 

It would be great to hear stories about how BRT has fared in other developed countries, against inevitable demands to compromise reliability because it might get in the way of cars. 

light rail "for dummies?"

A polarizing summary of "facts" about a light rail debate in Waterloo, Ontario has popped up in an Atlantic item by Nicholas Jackson.  After an introduction in which Jackson seems to confuse intercity high-speed rail and intra-city light rail, he invites us to admire a graphically rich presentation Waterloo light rail advocates.  It's at the bottom of this post. 

I cite this not to take a position on light rail transit (LRT) in Waterloo.  (I'm certainly open to it, and am following with interest a similar project in similar-sized Victoria, BC.)  I mean only to offer a useful illustration of the dangers of almost all "pro vs con" or "this vs that" or "with us or against us" framings of a question, in which all distinctions are reduced or distorted to fit the quarrel at hand.

Commenters are encouraged to nominate their favourite absurdities out of this piece, or to defend them.  Mine are mostly (but not all) in the table partway down.  Did you know light rail lines seem to cause high-tech companies to sprout decades before the line opens?  Did you know that regionwide populations of Ottawa and Waterloo can be compared to city limits populations of other cities, as convenient?  And what exactly can we learn from knowing the population of San Francisco in 1904, when they opened their first light rail line?  Might the absence of cars in that year make the cases hard to compare?

Snapsort's LRT for Dummies Infographic

This is well-intentioned, and perhaps in late stages of debate it's unavoidable.  Again, my response to it is not a view about light rail but rather about the style of argument, which assumes (contrary to this) that rail-bus distinctions overwhelm all others, and explain so much of the arc of history.

UPDATE:  This post isn't about the Waterloo light rail debate itself, but here are some sources on the subject:

BACKGROUND

Wikipedia: http://en.wikipedia.org/wiki/Rapid_transit_in_Waterloo_Region

The Region's Plan:

http://rapidtransit.region.waterloo.on.ca/

Opponents:

http://www.t4st.com/index.php?title=Main_Page

sydney: destroying the bus lane to save it

Why did I leave Sydney?  Partly because of things like this ...

TENS of thousands of bus commuters face hours of extra gridlock each week because traffic authorities have removed the requirement for an afternoon bus lane during widening of the M2 [the main radial freeway to the northwest suburbs of Sydney].

As part of the conditions attached to the $550 million M2 upgrade, Transurban [the toll road operator] was asked to set up a ''tidal flow'' bus lane to replace two bus lanes removed during construction. The flow of traffic on such a lane is reversed from morning to afternoon to match the heaviest traffic.

The Roads and Traffic Authority [RTA, the state highway agency] and the Department of Planning under the previous government dropped the requirement for a bus lane out of the city in the afternoon peak and agreed with Transurban the lane would be dangerous.

The idea that it's appropriate to remove transit lanes for a road construction project is backwards and upside-down.  Construction inevitably constrains a highway's capacity.  So if you want the economy to move, rather than just the cars, you go out of your way to attract more customers to transit during the construction period.  Instead, customers are being encouraged to drive instead of take the bus, which will make the freeway even slower, thus obstructing all road users regardless of mode and thereby maximizing the construction's negative impact on the local economy.

And this is priceless!

According to the Planning Department, the RTA said it had since done more traffic modelling and the lack of a bus lane would not affect travel times much. The RTA could not provide any extra modelling yesterday.

In other words:  "But mom!  It's not my fault!  Dad told me it was OK to destroy the bus lane!"

UPDATE:  So I was glad to see this today, the new government's much anticipated centralization of transit planning in Sydney that will strip RTA of much of its authority over public transport. 

[New transport minister Duncan Gay] said the RTA knew the public thought it had a ''culture of arrogance'', and that the organisation needed to change. ''You will not see the RTA the same after this process,'' he said.

Could be promising!

seoul: buses that tell you where they go?

Regarding Place has a good article on the recent reform of bus services in Seoul, South Korea.

Seoul has done something that I often hear people ask for, a simple citywide color scheme that helps make the structure of the bus system obvious.  The four colors of bus correspond to four types of service:

• Blue buses run in reserved median busways on major arterials, and appear to be mostly radial (into and out of the urban core.)
• Green buses are feeders that tend to run locally within a particular area.
• Red buses are "express" to and from outer suburbs.  It's not completely clear if this is peak commuter express or frequent all-day service (which I usually call "Rapid").  Express is a slippery word.
• Yellow buses are orbital lines, thus tend to be perpendicular to the blue and red ones.

I have mixed feelings about this sorting.  Usually I prefer to make distinctions about frequency and service span, but if overall frequencies are high I can certainly see the value in this system.  In a city with a clear distinction between radial and orbital directions, which Seoul seems to have, the distinctions can probably help people orient about which direction is which at various points, and to discern the general directions that each bus might go.

The same thinking extends to numbering system.  Traditionally, most big urban areas have had a sub-area based numbering, where in fact it may make more sense to number lines in ways that heighten the distinction between different service types. 

Most big cities, of course, simply don't have the centralized control to do this.  Los Angeles Metro has made an effort with its Rapid vs Local branding, but most color schemes are tied to the brands of municipal operators whose service is entangled with Metro's.  Cities with a single consolidated transit agency could do it.  In Australia, any state government could do it, though it would need to gain ownership of fleets that are currently owned by private operating companies. 

Obviously, you're sacrificing "operational flexiblity" in terms of being able to deploy any bus on any line.  Now and then in Los Angeles you'll see a Local bus on a Rapid line and vice versa.  I think Seoul deals with this by running all buses of one color out of one operating base, often with a separate contract operator, so the systems are functionally separate.

If you've been to Seoul and seen this system in action, please share your impressions.

rail-bus differences: premise or conclusion?

When you think about transit technologies, how do you categorize them?  And why?

Have a look at this first table, which sorts services according to the exclusivity of their right of way.  The terms Class A, B, and C are from Vukan Vuchic, describing the basic categories of "what can get in the way" of a transit service.

Is this table two rows, each divided into three columns?  Or three columns, each with two rows?  Which distinction is more fundamental, and which is secondary?

Right-of-Way Class vs Rail-Bus Distinction

	Class A Exclusive right-of-way and separated from cross traffic	Class B Exclusive right-of-way,  NOT separated from cross traffic.	Class C Mixed with traffic, including mixed with pedestrians.
Rail	Most rail rapid transit, using “third rail” power sources.  Most classic “subway” and “metro” systems.	Most “light rail” in surface operations.  Parts of some European and Australian tram networks.	Most North American streetcars.  Many European and Australian trams.
Bus	Separated busways:  (Brisbane, Ottawa, Bogotá, and segments in Los Angeles, Pittsburgh)  Freeway bus/HOT lanes.	At-grade busways:  Los Angeles Orange Line, Western Sydney busways, etc.	Buses in mixed traffic.

Well, if your objective is to get where you're going fast and reliably, the Right-of-Way Class tells you a lot about a services's potential to do that, while the rail-bus distinction, in isolation, tells you nothing.  The fact is, both rail and bus technologies are capable of the complete spectrum of possibilities.  Both can average 6 mph (10 km/h) in Class C situations, and both can run Class A at 60 mph (100 km/h) or more.

RIght-of-way isn't the only thing that matters for getting you where you're going.  There's also stop spacing, with its inevitable tradeoff between speed and local access.

Stop Spacing vs Rail-Bus Distinction

	Rapid, Limited (faster = fewer stops)	Local-stop (slower = more stops)	Express (one long nonstop segment)
Rail	“Subway”, “Metro”, some commuter rail.	Tram / Streetcar	Some commuter rail.
Bus	Bus Rapid Transit, “Rapid Bus”, “limited-stop” bus	Local bus	Commuter express bus (often on freeway)

 ... and of course there are other essential distinctions like frequency, which are also entirely separable from rail and bus technologies. 

UPDATE:  Please note, yet again, that contrary to early comments I am NOT claiming that these are the only distinctions that matter.  As I laid out in some detail here, there are several distinctions that matter.  In fact, one of the reasons that people cling so hard to the rail-bus distinction is that the other crucial distinctions are a little more complicated and require some thought, and it's hard to think about this stuff in the political space where decisions get made.

Rail services do tend to be presented in ways that "package" the various crucial dimensions of usefulness.  Typical metro systems, for example, are guaranteed to be frequent, with rapid stop spacing, and Class A right of way, because all three are intrinsic to the metro technology, so there's a psychological "packaging" effect when you see a metro map; you can be confident that this means a certain level of service. 

I think these tables are interesting because now and then I meet someone who divides the world rigidly into rail and bus, often aligning these categories with a rigid class distinction (William Lind, say) or simply claiming that rail does beautiful things and buses don't.  In that view, the different columns of these tables are secondary and interchangeable, while the rows express something absolute. 

Patrick Condon, for example, proposes that instead of building one rapid transit line (Class A, rapid stops) we could just build lots of streetcars (mostly Class C, local stops).  That can make sense if you judge technologies entirely on their influence on urban form, and prefer the kind of form that seems to arise from streetcars.  But it will be just incoherent to a transit planner who's been trained to help people get places, and wonders if he's being told that nobody cares about that anymore.  Because if you do care about personal mobility -- people getting where they're going, now, today -- you have to care about the columns.

I hope to leave this topic for a while, but I do think it's worth coming back to tables like this to ask yourself:  Do I tend to divide the world according to the rows first, or the columns?  If so, why?  Is my way of slicing this table something I've discovered about the world, or something my mind is imposing on it?

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.

sorting out rail-bus differences

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. 

 

Claims for the intrinsic superiority of rail over buses often arise from people’s actual experience of using the rail and bus systems in a particular city.  In these situations, you’re not comparing the intrinsic benefits of rail technology with the intrinsic features of bus technology.   You’re comparing a particular rail system against a particular bus system.  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 2009, the popular American weblog the Infrastructurist asked its readers whether streetcars are better than buses, and why.  Readers came up with 36 reasons, which 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. 

Misindentified Differences

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.
  
  
• 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. 
  
  
• 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!