See new updates at the end, based on comments to May 4.
Ricky Leong in the Calgary Sun on why Calgary should spend more money serving far-flung suburbs: Continue Reading →
Urban Structure
quote of the week: the reappearing desert
How little has changed since the 1830s! From Tocqueville's Democracy in America, published in 1835:
Sometimes the progress of man is so rapid that the desert reappears behind him. The woods stoop to give him a passage, and spring up again when he has passed. It is not uncommon in crossing the new States of the West to meet with deserted dwellings in the midst of the wilds; the traveller frequently discovers the vestiges of a log house in the most solitary retreats, which bear witness to the power, and no less to the inconstancy of man. In these abandoned fields, and over these ruins of a day, the primeval forest soon scatters a fresh vegetation, the beasts resume the haunts which were once their own, and Nature covers the traces of man's path with branches and with flowers, which obliterate his evanescent track.
Extended passage here, all equally relevant to urban planning. Hat tip: Ta-nehisi Coates, the Atlantic.
Photo: Tyson Jerry, NevadaCounty.com
how do you compare to your peers? should you care?
Admit it: You've always cared, at least in secret, about how you compare to your peers: your friends, your fellow students, your graduating class, your co-workers, your generation. Well, deep down, transit authorities and city governments care too, which is why comparing a city to other similar cities always gets attention.
Sometimes peer comparisons cause complacency, especially if you choose the wrong peers. Wellington has the highest transit mode share in New Zealand, but in a country with only one other big, dense city, that obviously shouldn't imply that it's reached nirvana. Working in greater Vancouver I always have to emphasize that they are doing so well by North American standards that they have to start comparing themselves to European port cities in their size class (Glasgow, Edinburgh, Copenhagen, Helsinki, Marseilles). My general advice: If your peer comparison says you're wonderful, throw a party and revel in this for 48 hours, then look for a more motivating group of peers.
At the other extreme, nothing is more motivating than being told that you're dead last among your peers. Earlier this year I worked (through my Australian employer MRCagney under the leadership of Ian Wallis Associates) on a peer comparison study for Auckland, New Zealand, which compared Auckland's transit performance with all the five biggest Australian cities plus a selection of North American ones. Download the full report here. Remember, if you're in any of the peer cities that it uses (Wellington, Brisbane, Perth, Adelaide, Sydney, Melbourne, Edmonton, Ottawa, Calgary, Vancouver, Honolulu, Portland, Seattle) this is your peer study too! Just keep the tables and refocus the text (citing the source of course!).
More generally, the report is a good illustration of how peer comparison can work at its best, and also of the cautions that must be shouted from the sidelines once the conclusions take fire in the media, as they certainly have in Auckland. From yesterday's New Zealand Herald:
Consultants have ranked Auckland last out of 14 cities – in New Zealand, Australia, Canada and the United States – included in a benchmark study for the average number of public transport trips taken annually by its residents.
Aucklanders also pay the highest fares of any of the cities, amounting to 24c for every kilometre travelled on the average 44 public transport trips they take each year, compared with 17c in Wellington.
The rest of the article is further grim statistics, plus quotations from political leaders demanding that something be done.
I'm sympathetic to Auckland Transport in this case. Remember, a city's transit performance is mostly about the physical layout of the city and the constraints on other modes; the quality of the transit system by itself can't overcome problems in those areas. The nature of the economy also matters. Wellington is much smaller but it has much more severe chokepoints in its urban structure. In fact, all travel between the northern and southern parts of the city must go through a single chokepoint less than 1 km wide, which is also the (very dense) downtown. Wellington's economy is dominated by government, which is generally a sector disposed to use transit heavily. All of these features are hugely important in driving Wellington's mode share above Auckland's, and yet they don't include anything about the respective quality of the transit systems.
Peer comparisons also carry the false assumption that everyone wants to be the same kind of city, and is therefore working to the same kind of goals. (This attitude, taken to extreme, produces the absurdity of top ten "best cities for transit" lists.) Low mode share for transit may mean your transit system is failing, but it may mean that it's not trying for mode share, or at least that it has other objectives or constraints that prevent it from focusing on that goal. It may just mean that your city has different values. It may mean the city stikes a different balance between cycling, transit, and walking based on its own geography.
Still, service quality matters, and there's a lot that Auckland can do. I hope the city's opinion leaders are listening to Auckland Transport as well as berating it, so that they understand the real choices that must be made to move Auckland forward. If there's a real conversation, great things can be accomplished.
Network Design for High Ridership, a Small Dense City Example
How do transit network designers go about their task? Surprisingly little has been written about this. You can pick up books that appear to cover the “network planning” or “network redesign” process and find examples of good and bad networks but rarely a description of how to do the design thinking itself. Continue Reading →
grids and the short diagonal (comment of the week)
Eric identifies an important issue for high-frequency grids, like those of Vancouver, Los Angeles, Chicago, Portland's eastside, etc … The short diagonal trip may be not much faster than walking. Here's how he describes it, complete with clever 1980s-style computer graphics:
When discussing grids, it is important to think about trips like the following:
Start
|
| (1/4 mile)
|
|********(1 mile)************
A—————————-B
*****************************|
*****************************|
*****************************| (1 mile)
*****************************|
*****************************|
*****************************|
*****************************|
*****************************C—–Finish
*****************************(1/4 mile)***(please ignore the '*' – they exist only to make the vertical lines go in the proper place).
The grid's approach to this trip would be to walk to A, then take a bus to B, then take another bus to C, then walk to the end. However, since each bus segment is so short, even with frequent service, the waiting time still becomes a huge deal.
For example, if we assume that the buses each run every 15 minutes the expected travel time might look something like this:
Time =
5 minutes (walk to A)
+ (0-15) minutes (wait)
+ (5-10) minutes (ride bus to B)
+ (0-15) minutes (wait)
+ (5-10) minutes (ride bus C)
+ 5 minutes (walk to destination)
= (20-60) minutesThe average 40 minute travel time is just 3.75 miles per hour, equivalent to a brisk walk, while the worst-case travel time is a mere 2.5 miles per hour, equivalent to a slow walk.
With the slow speeds and huge travel-time uncertainty in the above calculations, before you even consider the possibility of bunching leading to 20-30 minute waits, if the goal is simply to get to the destination quickly and reliably, transit can't even compete with walking, let along with driving.
This relegates the use of transit for these trips to people can't walk or bike and also can't afford to drive or spend $10 on a taxi ride.
Trips like these are not edge cases. I make trips like this quite frequently. Usually, I end up either biking or jogging the entire way or walking half way and taking a one-seat ride for the other half.
My personal opinion is not that the poor handling of such trips is a failure of transit, but rather that there are certain types of trips that transit is optimized for and short L-shaped trips isn't one of them. Short L-shaped trips are simply better accomplished by some other means, such as walking, jogging, skateboarding, bicycling, or even riding a taxi, while longer trips, especially trips in a straight line, allow transit to work more efficiently.
If anybody else has opinions on the matter, I look forward to hearing them!
Eric's point connects to a bunch of intersting issues:
- What other solution is there? Look at the overall mobility outcome from straight, fast, frequent lines in a grid pattern, and ask: OK, yes, this is not so convenient for the short diagonal, but what exactly can or should we do about that? In some cities, notably Los Angeles, you'll often find little circulators that serve some of these diagonals where there is a specific market for them, such as a link between two key local activity centers. But these are always going to be specialized because they are so much less efficient than the main grid lines.
- Note how much this outcome depends on the overall quality of the straight grid lines. Eric assumes they're pretty poor. In fact, the diagonal grid trip usually has a choice of two L-shaped paths ("over and down", or "down and over") so there's an opportunity to choose the better of these two, which will the the one that uses more frequent or faster services.
- Eric's assumptions are for a standard local-stop grid. Frequencies are assumed to be never better than 15 minutes, and travel speed, for example, is 5-10 min to go a mile, an average speed of only 6-12 mi/hr. Some urban lines are down in this range, but such performance should be considered a problem in urgent need of attention. Stop spacing and a range of minor infrastructure can have large impacts, and will yield benefits that are much greater than you'll get by dissipating your service over countless little diagonal shuttles. So there's much that can be done to improve the short-diagonal problem simply by focusing improvements on the grid lines.
In short, I agree with Eric's conclusion. Because I tend to live in urban places where most of my trips are short, I encounter the short diagonal problem all the time. It's a drag, but I deal with it because I'm pretty sure that it's geometrically impossible to "solve," except by undermining far larger benefits of a network that serves the whole city, and that moves fast enough to compete with cars, not with walking.
value capture as a tool for tying land use to transit
Yonah Freemark of the Transport Politic has an interesting post today on Toronto Mayor Rob Ford’s effort to build a subway line entirely through value capture – a process that captures, as revenue for the project, some of the profits that will arise from dense development around stations. Mayor Ford's initiative is not going well, partly because neighbors are objecting to the level of density that would be needed to support the subway.
Value capture has several connections to urbanist outcomes. A rail expansion program driven by value capture would:
- Tie completion of the line to zoning and development choices that allow major density around stations. For anyone who values compact and sustainable development, this is a feature, not a bug. It means a line cannot proceed unless communities on the line have agreed to significant density increases. Many urban regions are trying to make this linkage through policy, but tying it to the project's funding is obviously a far more effective way to keep land use planning tied firmly to the transit.
- Fail to serve existing high-density areas, such as SF’s Chinatown or Van Broadway. If you believe that existing density deserves as much service as new density, value capture won’t get you there.
- Fail to serve “social justice” outcomes, such as far SE Chicago Red Line extension to the extent that value capture requires displacement of populations.
I don't endorse or opposite value capture in the abstract, and I'm suspicious of public-private partnership in general, but there's no denying that first point, that when you want to ensure that the land use will be there to support your rail line, value capture keeps everyone much more focused on that outcome.
shared housing and shared transportation (guest post by alfred twu)
Alfred Twu lives in the Bay Area and is a long time transit rider. He has studied architecture and business and is also an active participant of the cooperative movement, having worked in artist, food, and housing co-ops. He is also an illustrator for my forthcoming book Human Transit.
Also known as cooperative living, co-ops, communes, intentional communities, or living with roommates, shared housing creates challenges and opportunities for transit service. It can increase density without zoning changes or construction. However, good transit service needs to already exist for this to happen. As such, shared housing's greatest potential is in increasing utilization of under-zoned but well served neighborhoods.
What is shared housing?
Shared housing denotes a group of unrelated people live in a single dwelling unit. Kitchens, bathrooms, and other living areas are shared, bedrooms may be shared or single occupancy. In the Bay Area, this model is known as a co-op or cooperative. Note that the word co-op has an entirely different meaning on the East Coast.
Shared housing has a long history in the Bay Area, dating back to boarding houses. The modern Bay Area cooperative housing movement began in 1933 with the founding of the Berkeley Student Cooperative.
Although some structures are built with shared housing in mind, usually the building is simply a repurposed large house. For example, Ridge House, a 38 person student co-op, used to be a mansion, while Cooperative Roots, pictured below, houses around 20 people in two adjacent single family houses.
What does this have to do with transit?
Let's look at two neighborhoods: one dense, and one sprawling. The denser neighborhood will usually have better transit service.
Now, if zoning ordinances prevent additional housing from being built in Sprawlville, that does not mean it's the end of the story. While zoning typically concerns itself with units per acre, the density that matters for transit service is population per acre, or more specifically, commuters per acre.
This is where shared housing comes in. When a neighborhood of single family houses goes from having one or two working adults per house, to having 4 to 8 working adults, as far as transit is concerned, it's a high density neighborhood.
The catch to this though, is that this can only happen where there is already good transit service. When a group of people share a house, they'll all want easy access to their jobs, which may be in different directions. Not all of them will take transit either – some of them will need to drive to their jobs, some people prefer to bike. This is why shared housing works so well with college students – everyone is going to the same place for their "job", so only one frequent route is necessary.
Case Study: Ashby BART (San Francisco Bay Area)
A number of my friends who used to live in shared housing as students have formed their own communities after graduation. Most are now in their mid 20s to early 30s. Some work office jobs with traditional 9-5 hours, others work retail jobs with varying hours. Over the last few years, about 30 communities of 4 to 18 people have been formed. Most cluster around the Ashby rail rapid transit station. Let's examine why.
- It is about halfway between the two big job centers in the area: UC Berkeley and Downtown Oakland.
- It is 20 minutes on rapid transit to the region's largest job center, downtown San Francisco.
- It is close to freeway on-ramps.
- It is on flat ground and within biking distance of a large number of commercial districts. Bike access is important since transit service in the evenings and on weekends is limited.
- It is not in itself a downtown district. This means there are a lot of large houses with lots of bedrooms and yards – the preferred housing type.
- There are already other co-ops in the area.
The one co-op not near a BART station — an outlier near the bay — is an artists' warehouse.
Ashby Station: Excellent transit service but low density
The Ashby station neighborhood, which currently consists of mostly single family houses, had long been targeted by planners for transit oriented development. It has an underground rapid transit station with train frequency of every 7 minutes on weekdays and 20 minutes at night and on weekends.
Ashby station neighborhood. Station is blue, parking lot is black.
However, the official plan to build 300 units of housing on the station parking lots met significant neighborhood opposition. Existing residents were concerned about losing the flea market that currently operates on weekends in the parking lot, increased traffic, and future upzoning of the area. The project was put on hold in 2006.
Shared housing, however, has achieved something similar with no official intervention.
Can the Ashby model be replicated elsewhere?
Using shared housing to increase neighborhood density offers a solution for low density areas where economic constraints or zoning limits the ability to build new housing units. The following factors are needed for its success:
Multimodal Job Access
Members of a shared house with long commutes tend to move out. Therefore a location needs good access to members' existing jobs, and potential future ones. Transit is just one part of the equation – those working 9 to 5 hours downtown. For the other members, good car and bike access to nearby commercial areas is needed for those working retail and service jobs on evenings and weekends.
Catalyst community and clustering effect
The Ashby area community began with just a couple of houses. However, the community grew rapidly as the original residents' friends also wanted to live nearby. UC Berkeley provided a feeder system with many members having already familiarized themselves with shared housing through living in the Berkeley student co-ops. In places far from colleges, immigrant neighborhoods can also benefit from the feeder effect.
One of the side benefits of shared housing is a group of residents will have a lot of purchasing power with their combined incomes, and will seek out the area that meets their needs best. Until most people live in shared housing, this means that a region will likely have only a small number of preferred neighborhoods.
Why not MacArthur? Station placement matters.
The next station down the line, MacArthur, is even better positioned in terms of access to transit and jobs. However, this station is located in a freeway median. As a result, a lot of the land walkable to the station is either paved over, or so close to a freeway that it is an unpleasant place to live. As a result, even though this area has been zoned for multistory apartments, few have been built.
Creating community: the station as social hub
Shared housing in the Ashby area occurred without any official planning – an existing community (recent UC Berkeley graduates) simply moved in. Where no existing community exists, social hubs such as coffee shops or community centers, located inside or directly next to the station, can aid the formation of the close relationships that shared housing requires.
fictional city seeks reality check
Did you draw maps of fictional cities when you were 8 years old? If so, you and I are part of a near-invisible, uncounted minority.
If that's you, I dare you not to be interested in this! Even if you just enjoy maps of other cities, here's a chance to study a city you've never seen before.
For the transit planning course that I'm developing, I've created a fictional city that's designed to present a range of major transit issues, while also being an interesting place. I considered using a real city, but in my experience, planning for a real city slides too quickly to details that obscure the big picture of how a good network works.
My introduction to the fictional city is here: Download Game Newport intro (.doc)
A rich set of map layers, created in Excel, is here: Download Game data backsave (.xls)
Both documents are covered by the assertion of copyright that covers all of this blog's material.
I'd love feedback, especially about these questions:
- Is the city realistic? Does it contravene what you perceive to be "facts" of geology, hydrology, urban economics, bird psychology, or post-1800 urban history?
- Have I omitted information that seems relevant to the basic task of designing a transit network? Note that I'm not asking "have I omitted anything that might be interesting?" The austere novelist and dominatrix who sells rare Asian herbs out of her Craftsman basement at 3315 W 43rd St while also being the invisible brains behind a top eco-fashion label is extremely interesting, but I only had a day to put this together.
Have fun! The premiere of the transit planning course is in Surrey, British Columbia near Vancouver on June 9-10. Last I checked there were a few places left. Details here.
UPDATES:
- Please do not try to comment based only on the illustration above. I'm getting many comments that indicate you've only looked at that image. You would need to download the files and look at the whole thing.
- Apologies to those who had trouble with the .docx and .xlsx versions; these old formats should be more widely compatible and convertible.
- The newest version now has layers for income and existing rail infrastructure.
Finally, I'm surprised at early comments that I don't have enough freeways! It's not a freeway dependent city, by choice. (See the .doc file above for more on the freeway wars.) But freeways that run only on the periphery and don't connect into the core are common enough in cities of this size class. See:
- Victoria, British Columbia, metro pop 330k. Two small shreds of freeway, created only as traffic required.
- Halifax, Nova Scotia, metro pop 372k. Fragments of an outer ring freeway, nothing into the city.
- Christchurch, New Zealand, metro pop 390k at least before February's earthquake. One 5-km shred of freeway approaching from the north (Kaiapoi to Belfast), but it's really just an extended bridge.
- Palm Springs-Indio, California, metro pop 365k. The area is bypassed on the north by Interstate 10, far from most of the urban cores.
- Gold Coast, Queensland, metro pop 591k. A massive highrise hotel/retail core (30-60 storeys) at Surfers Paradise, a highrise business core in adjacent Southport, but the only freeway bypasses 7 km to the west.
The last two of these are not, by any stretch, leftist car-hating enclaves. In fact, they're exceptionally car-dependent. Still, no freeways near the core. It's possible!
downtown networks: the oblique approach
How important is it that the transit services converging on downtown all go right to the core of downtown's demand? In a city with a strong downtown, a reactive, demand-driven view of planning will add more and more transit into downtown as demand requires, because the loads are always highest there. But sometimes, it can make sense to avoid the center of downtown, or to slide past downtown along one edge.
Zach Shaner's new proposal for the core area of Seattle is a nice example. (Click to enlarge and sharpen, or see JPG here: JPG )
You don't have to know Seattle to follow this. The core of downtown is the little shaded box on the left, where LINK light rail will be in a subway and other frequent buses will run on the surface. Most of the rest of the map area is also dense, so this is an area where you would expect a high-frequency grid to be possible, easily serving trips from anywhere to anywhere.
But the map area is also ferociously hilly, so fitting the classical grid to this terrain has always been a struggle. Still, Zach suggests that once the LINK light rail extension northward opens, ending at the University of Washington just off the north edge of the map, something remarkably gridlike might come into being.
Several of the design principles that I often advocate are at work here. First, Zach has focused on running on the fewest possible streets so as to provide the maximum possible frequency. Second, he's mapped both the existing and proposed networks so that you can see this frequency difference.
But he's also provided a nice example of the oblique approach to downtown, which is a way of balancing the distributive quality of a grid with the need to serve downtown's concentration of demand.
Look at the magenta line coming from the southeast. It's Line 7, now the single busiest bus line in Seattle. Off the map to the south, it extends about 5.5 km (3.4 mi) onward through dense, old, and historically low-income areas of the Rainier Valley. It touches the rail line at Mount Baker station, just inside the map, but it flows onward into the city, currently going right through downtown.
Zach proposes instead that Line 7 approach downtown but then bypass it just to the east, via Boren Avenue. He would do this to create a new crosstown (north-south) opportunity to reach dense north parts of downtown (including the South Lake Union redevelopment area and Seattle Center, which is right where Line 7 exits the map on the west edge) without going right through downtown's heart.
What would the dense downtown ridership of Line 7 do? Well, some of it would transfer to LINK where the two lines touch at the south edge of the map. Others, depending on exactly where in downtown they were going, might transfer to any of several very frequent east-west services crossing the line. But many who now seem to be going downtown would reveal that they're really going elsewhere. This is the key.
Line 7 ridership shows massive boarding and alighting downtown, and downtown is certainly an overwhelming destination. But you always have to ask if the concentration of downtown boardings is evidence of what people want or what the current network structure requires of them. People going to the dense and fast-growing areas on the north edge of downtown will find Zach's revision a dramatic improvement. Many others may be going still further north, to anywhere in the northern half of the city, in fact; they currently have to go through downtown to make their connections, because that's where their bus goes, but they could make the same connections to northward services from the revised Line 7, often with quite a savings of travel time.
Obviously, I don't have the data to validate exactly how many people are in each of these categories. I'm not even advocating Zach's design, but I do think it illustrates an important design concept, one that you will never think of if you're focused entirely on where your current ridership patterns seem to be leading.
Many major cities are facing unmanageable volumes of buses squeezing through a tight downtown. Sydney, where I lived for five years, has a remarkably similar predicament to Seattle's. One solution, in Sydney as in Seattle, is to let go of the idea that radial services aimed generally for downtown need to go right through the very center of it. If there is a sufficient diversity and richness of connection opportuntiies for reaching various parts of downtown, you can often create a better design by sliding past downtown obliquely, as Zach proposes that Line 7 should do.
I don't advocate or oppose Zach's design, but I do think it's a nice illustration of how to fit the "everywhere to everywhere" network design principles (such as the high frequency grid) to a very difficult terrain. It also raised some interestingly contrasting comments from different Seattle transit experts who've seen it; more on that in another post.
UPDATE: Zach explains his proposal to the Seattle transit community here.
can we define “livable and lovable” cities?
That's the nice slogan from a new Phillips Corporation initiative praised today in the Atlantic by NRDC's Kaid Benfield. The Phillips think tank suggests that we can gather all the qualities of a "livable and lovable" city into three virtues:
- Resilience, which replaces the more bureaucratic and depressing word sustainability, but means roughly the same thing. Some great work has already been done on the concept of resilience. There's already a Resilient Cities movement, and an excellent book on Resilience Thinking.
- Inclusiveness, which is about "social integration and cohesion," demonstrated for example in the lack of discrimination or social exclusion based on race, religion, age, and all the other usual categories.
- Authenticity, which means "the ability to maintain the local character of the city," including "heritage, culture, and environment."
Below is their graphic summary. (The PDF [Download] is much sharper!) Below that is a bit of affectionate heckling from me.
Personally, I have some practical discomfort with the framing of the Inclusiveness category because it is easily exaggerated into visions of a socialist paradise in which we have abolished competition. When Philips says that "inhabitants should have equal opportunities to participate in the activities of the city," does that mean that when our city's team in the playoffs, we'll give out tickets by lottery rather than selling them, in order to avoid discriminating against the poor? If we're talking only about nondiscrimination by extraneous demographic categories, fine. But when you imply that you can neutralize the impact of differences in wealth, you lose so much of the politicial audience — at least in North America, Australia, and the UK — that you've probably lost the game. This issue comes up often in transit, of course, notably whenever anyone suggests that in a capitalist economy, it's foolish not to use pricing to help citizens understand the intrinsic cost of things that they take for granted. It's a tough one.
Note, also, the lingering contradictory message in their framing of resilience. On the one hand, the train station signifies that resilient cities acknowledge their "interdependence" with other cities. On the other hand, the emphasis on local farms and local energy generation suggests the opposite, that resilient cities aspire to greater and greater self-reliance. This is philosophically interesting, especially because high volumes of international trade — including in food, which is the opposite of local self-reliance — are the most reliable mechanism that human society has found to prevent large-scale wars.
I make both of these comments in the spirit of meditation. I am not claiming to know how better to define inclusiveness or resilience. Rather, I'm just marvelling at how difficult it is.