The Chinese Straddle Bus Exists! What Now?


The Chinese straddle bus has now been built, and run on a test track!  Whee! Here’s the gee-whiz video.

As I said before, I think that especially in wealthy countries, this thing is mostly useful as a parable, whose message is:  Look how much money people will spend on infrastructure whose sole purpose is to avoid taking any space from motorists.

If the thing has any application, it’s probably not in Europe or North America, because:

  • It’s massively capital intensive.  The little rail-like running-ways in the street are the least of it, and the fleet is the second-least.   The stations must be massive elevated structures, with a mezzanine above the top of the bus.  Existing bridges would almost all need to be raised.   Countries with high construction costs will find this a barrier.
  • It will serve stations located on expressways, which tend to be bad places for the pedestrians that the bus will attract and disgorge.  The only solution to this is massive grade separation, leading to a continuous pedestrian plane at the station level, well above the street.  This leads to urban design that essentially abandons the ground plane to cars and rebuilds an entire pedestrian city above it.
  • The vast raised pedestrian plane was a hot idea for about 15 minutes in the 1970s, giving us London’s Barbican, Paris’s La Défense, Los Angeles’s Bunker Hill, etc etc.  Today, most European and North American urbanists hate these places and insist on solving problems on the ground plane, though of course the pendulum could swing again.  But it’s much more common and accepted in East Asia, and to some extent in former Soviet countries.
  • There’s also the problem that if you build this thing in an existing dense city, you are building it right outside of someone’s window.  So you probably need a political structure that can make and enforce highly controversial decisions, as opposed to the kind of deference to public protest that prevails in most Western democracies.
  • You really have to redesign big districts around this thing, which is another big barrier unless we are talking about entirely new areas.  A high pedestrian plane only works if the idea is shared by many surrounding buildings.
  • Where this thing connects with underground subway lines, your mezzanine for this elevated thing is at least four stories away from the subway’s mezzanine.   This requires high-volume vertical circulation, which no inventor has ever really cracked.  Elevators are really inefficient at high volume, and escalators are really slow at it.
  • The nature of this technology makes it hard to demonstrate at the right scale.  There is a basic conflict between “huge capital expenditure” and “demonstration of new technology.”  It’s the same problem that monorails and maglevs and “Personal Rapid Transit” and many other cool ideas have had.  Inventors need places to do demo projects.  But it’s not smart for a city to agree to be Version 1.0 of something, while also spending billions on the assumption of its permanent success.  This is how cities end up with stranded transit assets that can become net barriers to good transit (see Scarborough RT, Toronto, or the airport maglev in Shanghai, etc etc.)

(Update: In the third top-level comment below, Brian Smith points out that the surface space this thing takes is still wider than a bus lane, so why not just do aa busway?  He also points out that the vehicle is rigid and the test track was straight.  What happens when it goes around curves?   It takes more horizontal space of course.  And it seems to rely on a ground-level third-rail, which is considered wildly unsafe in the business.)

Having said that, if anyone can pull this off at scale, it’s probably China, which seems to tick all the boxes I’ve identified.  They have the sufficiently centralized decision making, low enough construction costs, ability to do things at scale, and relative indifference to Western aesthetics that this thing requires.  They are also building entirely new districts, which offer the best possibility for actually organizing a place around the correct elevated ground plane. So yes, it may happen, and it may do some good.  Which doesn’t mean it’s not, deep down, ridiculous.

Does the History of a Technology Matter?


Mater Hill busway station, Brisbane

Ben Ross has a nice long read in Dissent about the history of Bus Rapid Transit, noting all the ways it’s succeeded, failed, and been co-opted by various non-transit agendas.  He’s especially interested in the way various petroleum-and-asphalt interest groups have supported BRT as an alternative to rail for reasons that probably don’t have much to do with their love of great public transit.  All this is worth reading and knowing about.

But what, exactly, should we do with this history?  Practically everything that breaks through into the public discourse has private public relations money behind it, and that money always has different goals than you and your city do.  That’s why you should always lean into the wind when reading tech media.  But just as it’s wrong to fall for everything you read in corporate press releases, it’s also wrong to reflexively fall against them.  (Cynicism, remember, is consent.)

Galileo paid the bills, in part, by helping the military aim cannonballs correctly.  Does that mean pacifists should resist his insight that Jupiter has moons?

So while I loved Ross’s tour of the history, I reject his dismissive conclusion:

Buses will always be an essential part of public transit. Upgrading them serves urbanism, the environment, and social equity. But a better bus is not a train, and bus rapid transit promoters lead astray when they pretend otherwise. At its worst, BRT can be a Trojan horse for highway building. Even at its best, it is a technocratic solution to a fundamentally political problem.

The term technocratic is really loaded here.  Given the new “revolt against experts” trend in our politics, we urgently need to recognize  hard-earned expertise and to distinguish it from elite selfishness, but technocrat is a slur designed to confuse the two.


RBWH busway station, Brisbane

There are some great bus rapid transit systems out there, and not just in the developing world.  The mixed motives that underlie BRT advocacy don’t tell us anything about where BRT makes sense, any more than the mixed motives behind rail advocacy do.

A light reading of history can help you recognize the prejudices that may lay behind advocacy on all sides.  But then you have to set that aside, and think for yourself.


Portland: Frequent Bus Performance Approaching Light Rail’s

Here's an interesting chart:

Tri Met Ops Cost per Ride

This is a year's trend comparing bus and light rail (MAX) service in Portland's transit agency, TriMet, from the performance dashboard at the TriMet Transparency and Accountability Center webpage.  

The metric here is operating cost per boarding ride.  This is a good overall measure of how effectively a transit agency is liberating and moving people, where down means good.  (I prefer this ratio upside down: ridership per unit cost or "bang for buck," so that up means good. but this is obviously a chart by finance people who always want cost on top.)  This is a "macro" metric.  Practically everything a transit agency does affects it, so it's lousy diagnosis but not bad if you only have bandwidth to convey one measure.

Most American transit data just compares bus and rail, and inevitably shows bus performing worse.  You'll see that here too if you just look at the wide solid lines.  From this we get endless ignorant journalism lamenting the poor performance of the city bus, as though all city buses are basically alike.

What if we separated out highly useful and liberating bus service as a separate category?  That isn't exactly the distinction made here but it's close.  TriMet's Frequent Service network (still being restored, but mostly now back in existence) is the network of all services that are almost always coming soon.  

This chart says two remarkable things:

  • Frequent bus performance is now very close to light rail performance.   
  • The spread between Frequent Bus and infrequent bus is usually bigger than the spread between all buses and light rail.

The lesson is pretty clear:  The "city bus" is a misleading category, and the much-fetishized difference between bus and rail may matter less than whether the services are designed to be useful.  And when it comes to usefulness, no one variable capture that more than frequency.  

Transitmix continues its development

By Evan Landman. 

Last summer, we covered an exciting new transit planning tool called Transitmix. Transitmix grew out of a Code for America project that sought to create a web-based tool to automate much of the complex yet mundane work that goes on in the background during transit planning. Cost estimation, line measurement, population and employment coverage analysis, are all examples of tasks that require time and effort such that they cannot all be carried out in real time during a planning meeting or workshop.

The team at Transitmix reached out to transit planners all over the county (including our firm), learning what did and didn't work about current practices and workflows. They created a beta version of a simple online tool that hinted at what might be possible. Finally, last week, Transitmix released a new video announcing the impending release of the professional version of the application, with critical features that offer the promise of a dramatically simpler, more open, and more easily understood transit planning tool.

Dynamic demographic and employment mapping and analysis, and side-by-side network and route comparisons are the main new features implemented here, to go along with the live updated costing, and deeply configurable frequency, span, and cost parameters the older version already includes. Transitmix continues to impress, creating a tool that simplifies and demystifies procedures that are too often known only to practitioners. We look forward to getting our hands on the full-featured product.

Luca Guala: driverless buses will be more transformative than driverless taxis

34Part 2 of my letter from Luca Guala, of the Italian consulting firm Mobility Thinklab.  (Part 1, on personal rapid transit, is here.)

Last summer, we tested driverless minibuses along a route of 1.3 km on a pedestrianized boulevard in Oristano, a small town in Italy. The idea was to test driverless vehicles mixed with traffic.

Why minibuses and not taxis? Firstly, because it is much simpler to teach a robot to follow a fixed route, rather than teach it to go anywhere the passengers want to go. Such a system is already operational in Rotterdam ( and it works well, but it has one drawback: the tracks are segregated and they represent an ugly severance in the urban tissue.

But if the vehicles are allowed to run with cars cyclists and pedestrians, a public transport route can be “adapted” with unobtrusive measures to accept driverless vehicles, and the people sharing the road will quickly learn to live with them. The main problem here was not technical, as legal.

Hence the idea of testing similar vehicles in an open field mixed with pedestrians. The first test we did had mixed results, the second test that will be done in La Rochelle, France this winter will take advantage of all that we learned in Oristano.

So what did I learn from all of this? That driverless cars very likely have a bright future, but cars they will always be. They may be able to go and park themselves out of harm’s way, they may be able to do more trips per day, but they will still need a 10 ft wide lane to move a flow of 3600 persons per hour. In fact, the advantage of robotic drivers in an extra-urban setting may be very interesting, but their advantages completely fade away in an urban street, where the frequent obstacles and interruptions will make robots provide a performance that will be equal, or worse than, that of a human driver, at least in terms of capacity and density.

True, they will be safer (especially because the liability for accidents will be borne upon the builder) and a robotic traffic will be less prone to congestion (I envision robotic cars marching orderly like robots, packed at 1.5 second intervals, while their occupants fume wishing they could take the wheel perfectly aware, but not at all convinced that their robocars are more efficient drivers than they are – or worse, they DO take the wheel overriding the … robots!), but I do not expect driverless cars to dramatically increase the capacity of a lane to transport persons. 

Driverless buses, on the other hand offer an interesting feature: the human driver is no longer needed, removing an important cost and several constraints.  This allows them to serve efficiently and economically low-demand routes and time bands, while allowing [agencies] to concentrate the number of manned buses on high demand routes at little added cost. 

I take all this automation talk with a grain of salt still, as I don't think we've begun to explore the human response to it.  But Luca is right about the key point:  driverless buses are a much easier problem than driverless cars, and their space-efficiency will continue to be crucial in busy corridors where even driverless cars will add up to gridlock.

Luca's last paragraph suggests that driverless buses will start with smaller vehicles in simpler situations, which is a possibility.  But of course, once the concept is proven, the economics of driverlessness will create pressure to bring the technology to big buses.  The same logic is also driving the movement to run fully-grade-separated without drivers, on the model of Vancouver, Dubai, and Paris.  The logic of driverless trains is easy: with automated train controls systems there is really not much for a driver to do in non-emergency situations, and these cities have found that those tasks are easily automated.  We are all used to small systems of this type, because we encounter them in large airports.  The driverless bus in traffic is a harder problem, but we will have solved all of those problems if we ever develop driverless cars.  In fact, the problem of the driverless bus, which never goes into alleys or minor streets, should be considerably easier, since navigation turns out to be one of the biggest challenges for the driverless car.  

Note also that the challenge of planning for driverless cars is not in envisioning a utopia where they have complete dominion over the street.  The future must be evolved, which means that we must plan for the interim state in which some cares are driverless and most aren't.  That is a situation where driverless buses could thrive, because they will be competing with something that — in terms of poor capacity utilization — resembles today's traffic on major streets, not a world optimized for the driverless car.

As Luca indicates, we know what the problem with driverless transit will be: long fights with labor unions who feel entitled to cradle-to-grave  security in a single job.  It will be one more kind of automation that requires people to retrain and to participate in a more complex and competitive economy.  In an ideal system, many drivers would be replaced by support jobs such as fare inspectors and roving problem-solvers; as on Vancouver's SkyTrain.  This seems to be what Luca is envisioning when he speaks of the continued need for "manned" services.  

But the real result of massively abundant transit — which is the real point of the large driverless bus  – will be massively more opportunity for all kinds of innovation and commerce to happen in a city,  unconstrained by the limits of car-based congestion.  That's a wrenching change, and I am as adamant as anyone about the need to protect workers from exploitation.  But in the long run, over a generation or two, the outcome will more interesting jobs for everyone.  Bus drivers shouldn't encourage their children to go into the same profession with the same expectations, but that's true of many jobs — perhaps even most jobs — in this rapidly changing world.

no, autonomous cars will not “abolish transit” in dense cities

Is transit headed for a collision with self-driving cars?  David Z. Morris in Fortune writes about how anti-transit Republicans are using the prospect of self-driving cars to argue against transit investments.

Alarmingly, he quotes nobody who can actually refute this argument, except in the fuzziest of terms.

Here is the recommended response:

We are currently in that phase of any new techno-thrill where promoters make grandiose claims about the obsolescence of everything that preceded them.  Remember how the internet was going to abolish the workplace?

In any case, technology never changes facts of geometry.  However successful driverless cars become, transit will remain crucial for dense cities because cities are defined by a shortage of space per person.  Mass transit, where densities are high enough to support it, is an immensely efficient use of space.

(Remember, a great deal of bus transit is in places where densites are not high enough to allow it to succeed; this is evidence of anti-ridership “equity” or “coverage” policies, not of transit’s failure.  Driverless taxis could certainly replace transit in those areas, assuming the pricing were gotten right, thus allowing transit agencies to focus on their core business.)

In many cases, people talking about driverless cars replacing transit are talking from an outer-suburban point of view, based on the experience of low-density, car-dependent places that are unsuited to high-ridership transit.  In those settings, if density is not increasing, they are probably right.  Driverless taxis will be more efficient than transit in these areas.

But all over the world, people are moving into dense cities, where even autonomous cars can’t replace a bus full of 60 people or a train full of hundreds.  There simply isn’t enough space to put walls between every pair of travellers, as the car model of transportation requires.  Nor will driverless taxis ever be there whenever you need them as great transit lines will.  Like bikeshare systems, they will experience surges where many of the vehicles are in the wrong place.

A city can of course choose to sprawl and avoid density to the point that driverless cars could dominate.  But in so doing it will fail to create a place that the 21st century economy will reward.  Real estate prices are already telling us that the market has chosen dense cities as the highest value form of development.  There is no dense city in the world that does not rely heavily on transit, for reasons of space-efficiency that none of the new technologies can change.  (Yes, autonomous vehicles will use space more efficiently than private cars do, but this is saying very little compared to what a great rapid transit network is achieving.)

Again, technology never changes geometric facts.  And the problem of cars in dense cities, and transit’s superiority there, is a geometric fact, a fact about space and its scarcity.


quote of the week: “rail is only part of the equation”


Trains would be just one layer of a comprehensive, multi-modal network that greatly enhances both neighborhood and regional accessibility for people all across the [Los Angeles] region. …

A singular focus on rail would divide the region into two: neighborhoods with rail and neighborhoods without. Such a future would perpetuate income inequality as housing costs rise near stations and station areas would be choked with traffic congestion. …

Getting our existing buses out of traffic is the quickest, most cost-effective means to bring high-quality transit to the greatest number of Angelenos.

Juan Matute, UCLA Institute of Transportation Studies
from a discussion called "Trains are Not the Silver Bullet"
 at ZocaloPublicSquare

This is from a collection of commentary about the the role of rail in the larger context of transit investment strategies.  Read the whole thing!