Monthly Archives: February 2014

The zoning straightjacket

The more things change, the more they remain the same.

DC is nearing the end of a lengthy process to re-write the city’s zoning code. The re-write is mostly a reorganization, combining overlays and base zones in an effort to rationalize a text that’s been edited constantly over the better part of half a century. While there are a number of substantive policy changes (all good and worth supporting – reducing parking requirements, allowing accessory dwelling units, allowing corner stores, etc.), the intent of the re-write is to look at the structure and policy of the code, rather than look for areas of the city where the zoning classification should change.

Actual re-zoning will require an update to the city’s comprehensive plan (as all zoning changes must be consistent with the comprehensive plan). As promising as the policy changes in the zoning re-write may be, they do not represent any kind of change to the basic city layout – areas currently planned for high density will see more development, and areas zoned for single-family homes will not.

Last year, the District Government and the National Capital Planning Commission worked on dueling reports (see the documents from DC and NCPC) at the request of Congress on the potential for changing DC’s federally-imposed height limit. Leaving aside the specific merits and drawbacks of this law, the planning team needed first to identify areas that would likely see taller buildings if the height limit were to change.

I’ve borrowed the title of this post from Charlie Gardner, to try to show how little room we’ve planned in our cities for change. Even with the perception of runaway development in growing cities, the amount of space that’s set aside for a physical transformation is remarkably small. Zoning is a relatively new force shaping our cities – about a century old. We’re now seeing the effects of this constraint.

Consider the following examples of freezing city form in place via zoning codes:

Old Urbanist – The zoning straightjacket, part II, writing about Stamford, Connecticut:

In general, the zoning maps continue to reflect the land use patterns and planning dogma of the 1920s, with a small, constrained downtown business district hemmed in by single-use residential districts through which snake narrow commercial corridors.

This, if nothing else, seems like a fundamental, if not the only, purpose and challenge of city planning: accommodating population growth in a way that takes into account long-term development prospects and the political difficulty of upzoning low-density SFD areas. In light of this, can a zoning code like Stamford’s, with a stated purpose of preserving existing neighborhoods in their 1960s form, and resistant to all but changes in the downtown area, really be called a “planning” document at all? The challenges that Stamford faces are not unique, but typical, and progress on them, as zoning approaches its 100th birthday, remains the exception rather than the rule.

Better Institutions – Look at the Amount of Space in Seattle Dedicated to Single-Family Housing, writing about Seattle:

Putting aside the issue of micro-housing and apodments, [ed – I wrote about Seattle’s apodments here] what I’d actually like you to draw your attention to is everything that’s not colored or shaded — all the grey on that map. [ed – here is a link to the map] That’s Single-Family Seattle. That’s the part of the city where most people own their homes, and where residents could actually financially benefit from the property value-increasing development necessary to keep Seattle affordable. It’s also the part of the city that’s off-limits to essentially any new residential construction because preserving single-family “character” is so important. And it’s why residents in the remaining 20% of the city can barely afford their rents.

Dan Keshet – Zoning: the Central Problem, in Austin, Texas:

Zoning touches on most issues Austin faces. But with these maps in mind, I think we can get more specific: one of the major zoning problems Austin faces is the sea of low-density single-family housing surrounding Austin’s islands of high residential density.

Daniel Hertz – Zoning: It’s Just Insane, in Chicago, Illinois:

So one thing that happens when I bring up the fact that Chicago, like pretty much all American cities, criminalizes dense development to the detriment of all sorts of people (I’m great at parties!) is that whoever I’m talking to expresses their incredulity by referencing the incredible numbers of high-rises built in and around downtown over the last decade or so. Then I try to explain that, while impressive, the development downtown is really pretty exceptional, and that 96% of the city or so doesn’t allow that stuff, or anything over 4 floors or so, even i n neighborhoods where people are lining up to live, waving their money and bidding up housing prices.

Chris D.P. – The High Cost of Strict Zoning, in Washington, DC:

Across town, the Wesley Heights overlay zone strictly regulates the bulk of the buildings within its boundaries for the sake of preserving the neighborhood character. Is it ethical for the city government to mandate, essentially, that no home be built on less than $637,500 worth of land in certain residential neighborhoods?

The largest concentration of overly restrictive zoning (from an economic perspective) appears to be downtown, along Pennsylvania Ave and K Streets NW. If we value our designated open spaces, and won’t concede the exclusivity of certain neighborhoods, but understand the environmental and economic benefits of compact development, then isn’t downtown as good a place as any to accommodate the growth this city needs?

DC’s height study shows a similar pattern. The very nature of the thought exercise, the hypothetical scenarios for building taller and denser buildings in DC requires first identifying areas that might be appropriate for taller buildings. As a part of this exercise, the DC Office of Planning identified areas not appropriate for additional height based on existing plans, historic districts, etc.

These excluded areas included: all federal properties, all historic landmarks and sites; low density areas in historic districts; all remaining low density areas, including residential neighborhoods; institutional sites and public facilities. Those areas are illustrated in the Figure 4 map below. The project team determined that sites already designated as high and medium density (both commercial and residential) were most appropriate for the purposes of this study to model increased building heights because those areas had already been identified for targeting growth in the future through the District’s prior Comprehensive Plan processes.

Put this on a map, and the exlcuded areas cover 95% of the city:

Now, this isn’t analogous to the comparsions to areas zoned for single-family homes in other cities, nor are all of the areas in red innoculated from substantial physical change. However, it does illustrate just how limited the opportunities for growth are. It broadly parallel’s the city’s future land use map from the Comprehensive Plan, where large portions of the city are planned for low/medium density residential uses (click to open PDF):

The plan’s generalized policy map also illustrates the extent of the planned and regulatory conservation of the existing city form (click to open PDF):

The areas without any shading are neighborhood conservation areas.

All of this should be reassuring to those concerned about the proposed zoning changes, since all changes must be consistent with the comprehensive plan.

Don’t rule out elevated rail in cities

Toronto is looking to Honolulu for transit inspiration – looking to tap into the potential for elevated rapid transit to improve the city’s transit expansion plans. However, key city officials are extremely concerned about the impacts of elevated transit to the city. Skepticism is good, any may be required to ensure that elevated rail is successfully integrated into an urban environment, but it shouldn’t be an automatic disqualifier for the kinds of improvements that make rapid transit possible. From the Toronto Star:

Toronto chief planner Jennifer Keesmaat cites the shadow that a structure like the [elevated Gardiner expressway] casts on the street below. She also brandishes one of the chief arguments for building Toronto’s LRTs in the first place.

“From a land use planning perspective, if our objective in integrating higher order transit into our city is to create great places for walking, for commerce, living,… elevated infrastructure doesn’t work so well for any of those objectives,” she said.

It’s true that making elevated rail work in urban areas is a challenge, but it shouldn’t be so easily dismissed. Of particular concern is the willingness to equate the visual impact of the six-lane Gardiner Expressway with a potential two-track elevated rail structure. The other key concern is the equivocation of grade-separated transit with at-grade light rail.

Toronto seems full of transit terminology confusion these days. Embattled Mayor Rob Ford has been pushing for subways as the only kind of transit that matters (SUBWAYS SUBWAYS SUBWAYS!) regardless of context or cost. Meanwhile, the transit agency is looking to implement a ‘light rail’ project that features full grade separation and an exclusive right of way – in other words, a subway. Ford opposes the light rail plan in favor of an actual, tunneled line with fewer stations and higher cost. Much of the rhetoric seems focused on equating light rail with Toronto’s legacy mixed-traffic streetcar network.

However, just as Ford’s dogmatic insistence of subways at any cost is irresponsible, Keesmaat’s suggestion that at-grade LRT can accomplish the same transit outcomes as grade-separated LRT can is equally misleading. Remember the differences between Class/Category A, B, and C right of way (from Vukan Vuchic, summarized here by Jarrett Walker), paraphrased here:

Category C – on-street in mixed traffic: buses, streetcars, trams, all operating in the same space as other street users.
Category B – partially separated tracks/lanes: exclusive right of way for transit, but not separate from cross-traffic. Vuchic dubs this “Semirapid Transit.” often seen with busways or light rail.
Category A – right of way exclusive to transit, separated from all cross traffic: This is required for rapid transit. Examples include subways/metro systems and some grade-separated busways.

Transit system types by class of right-of-way. X-axis is system performance (speed, capacity, and reliability), Y-axis is the investment required.

The distinction matters because the quality of the transit service is substantially different. Service in Class A right of way will be faster and more reliable than Class B, at-grade LRT. Part of the planning challenge is matching the right level of investment (and ROW category) to the goals for the system. However, even with the need to balance transit goals with those for urban design, planners like Keesmaat shouldn’t categorically dismiss the possibility of building Class A transit facilities.

Part of the confusion might be from the technology. A catenary-powered rail vehicle can operate in Class A, B, or C right of way, and fill the role of streetcar, light rail, or metro – all with little change in technology. Consider San Francisco, where Muni trains operate in all three categories – in mixed traffic, in exclusive lanes, and in a full subway. The virtue of light rail technology is flexibility, but that flexibility can also confuse discussions about the kind of transit system we’re talking about. The vehicle technology isn’t as important as the kind of right-of-way. Indeed, many of the streetcar systems that survived the rise of buses precisely because they operated in Class A and B rights-of-way.

Keesmaat certainly appreciates the difference between the kind of regional rapid transit you’ll see in Honolulu and at-grade LRT:

“The Honolulu transit corridor project is really about connecting the city with the county…. It’s about connecting two urban areas. That’s very different from the context we imagine along Eglinton where we would like to see a significant amount of intensification along the corridor,” said Keesmaat.

At the same time, the kind of transit she’s describing and the kind of land use intensity aren’t mutually exclusive at all – quite the opposite.

Subways are nice, but require a high level of density/land use intensity. Payton Chung put it succinctly: “no subways for you, rowhouse neighborhoods.” Payton cites Erick Guerra and Robert Cervero’s research on the cost/benefit break points for land use density around transit lines. This table to the right shows the kind of density needed to make transit cost-effective at various per-mile costs.

The door swings both ways. Rowhouse densities might not justify subways, but they could justify the same Class A transit if it were built at elevated rail construction costs. Finding ways to lower the high US construction costs would be one thing, but given the systemic increase of US construction costs, using elevated transit would be a good way to extend Class A rights-of-way to areas with less density.

Instead of categorically dismissing elevated rail, work to better integrate it into the urban environment. Consider the potential for the mode to transform suburban areas ripe for redevelopment. Wide rights-of-way along suburban arterials are readily available for elevated rail; redevelopment can not only turn these places into walkable station areas, but also help integrate elevated rail infrastructure into the new built environment.

Keesmaat’s concerns about elevated rail in Toronto stem from the impact on the street:

“The Catch22 with elevating any kind of infrastructure – a really good example of this is the subway in Chicago – not only is it ugly, it creates really dark spaces,” she said.

It’s not just the shadow but the noise of elevated transit lines that can be problematic, said TTC CEO Andy Byford. If you build above the street you’ve also got to contend with getting people there, that means elevators or escalators.

First, it’s not clear what Byford is talking about: accessing subway stations also requires elevators and escalators. The nature of grade separated rights-of-way is that they are separated from the grade of the street.

Keesmaat’s concerns about replicating Chicago’s century-old Els are likely misplaced. No one is building that kind of structure anymore – and a quick survey of newer elevated rail shows slimmer, less intrusive structures. Reducing the visual impact and integrating the transit into the cityscape is the real challenge, but the price advantage and the benefits of Class A right-of-way cannot be ignored. It’s not a surprise that the Star paraphrases UBC professor Larry Frank: “On balance… elevated transit should probably be considered more often.”

Driverless cars: implications for city planning and urban transportation

Nevada autonomous vehicle license plate. CC image from National Museum of American History.

Building on the implications of driverless cars on car ownership, as well as the notion that planners aren’t preparing for the rise of autonomous vehicles, I wanted to dive further into potential implications of widespread adoption of the technology. Nat Bottigheimer in Greater Greater Washington argues that city planning as a profession is unprepared for autonomous vehicles:

Self-driving cars address many of the safety and travel efficiency objections that Smart Growth advocates often make about road expansion, or the use of limited street space.

Part of Bottingheimer’s concern is a lack of quantitative analysis, particularly as it relates to the impacts of self-driving cars. However, the real debate is about qualitative values that feed into our analysis.

The officials responsible for parking lot and garage building, transit system growth, bike lane construction, intersection expansions, sidewalk improvements, and road widenings need to analyze quantitatively how self-driving cars could affect their plans, and to prepare alternatives in case things change.

There is one over-arching problem with this approach: our current quantitative analysis all too often is nothing but bad pseudo-science. Donald Shoup has extensively documented the problems with minimum parking requirements in zoning codes, for example. Here, poor policy with vast unintended consequences is based on some level of flawed quantitative analysis, the kind that does not acknowledge the inherent uncertainty in our understanding or ability to project the future. Instead, the analysis is based on assumptions, yet the assumptions are really value-laden statements that carry a great deal of weight.

Even the very structure of the planning and regulation for the future carries a bias: a requirement to provide parking spaces in anticipation of future demand will, by nature, ignore the complexity of the marketplace for off-street parking and the natural range of parking demand.

Bottigheimer is also concerned about the impacts of self-driving cars on future land use forecasts:

Planners need to examine how travel forecasting tools that are based on current patterns of car ownership and use will need to change to adapt to new statistical relationships between population, car ownership, trip-making, car-sharing, and travel patterns.

By all means, we need to adjust our forecasting tools. However, we shouldn’t be doing so simply based on the arrival of a new technology. We should adjust them because they’re not particularly accurate and their erroneous projections have large impacts on how we plan. Driverless cars aren’t the problem here. The problem is in our assumptions, our inaccurate analysis, and our decision-making processes that rely on such erroneous projections.

Leaving the limitations of quantitative analysis aside for the moment, we can still hypothesize (qualitatively, perhaps) about the future world of driverless cars. Assuming that autonomous vehicles do indeed reduce car ownership and begin to serve as robo-taxis, we can sketch out plausible scenarios for the future. We assume car ownership will decrease, but vehicle-miles traveled may increase.

City Planning and Street Design:

One of Bottigheimer’s chief concerns is that “planners and placemaking advocates will need to step up their game” given the potential benefits for safety, increased car capacity,

As mentioned above, much of the ‘safety’ benefits are about cars operating in car-only environments (e.g. highways), when the real safety challenges are in streets with mixed traffic: pedestrians, bikes, cars, and buses all sharing the same space. In this case, the values planners and placemaking advocates are pushing for remain the same, regardless of who – or what – is driving the cars. The laws of physics won’t change; providing a safe environment for pedestrians will still be based on the lowest common denominator for safe speeds, etc.

The biggest concern should be in the environments that aren’t highways, yet aren’t city streets, either. Will driverless cars forever push stroads into highway territory? Borrowing Jarrett Walker’s phrasing, technology can’t change geometry, except in some cases at the margins.

Instead of a technical pursuit of maximum vehicle throughput (informed by quantitative analysis), the real question is one of values. The values that inform planning for a place or a street will set the tone for the quantitative analysis that follows. Maximizing vehicle throughput is not a neutral, analytical goal.

Congestion:

Congestion is a more interesting case, as it will still be an economic problem – centralized control might help mitigate some traffic issues, but it doesn’t solve the fundamental economic conundrum of congestion. Here, too, the economic solutions in a world of human-driven cars will have the same framework as one with computers behind the wheel.

Driverless cars might change the exact price points, but they don’t alter the basic logic behind congestion-mitigation measures like a cordon charge in London or Stockholm, or like Uber’s surge pricing (efficient and rational as it might be, but perhaps too honest). Again, technology can’t fundamentally change geometry. Cars will still be cars, and even if driverless cars improve on the current capacity limitations of highways, they do not eliminate such constraints.

Qualitative Concerns:

Instead of twisting ourselves in knots over projections about the future that are sure to be wrong, planning for autonomous cars should instead focus on the values and the kind of places we want to plan for. We should adjust our policies to embrace the values of the communities (which alone is a challenging process). We should be aware about the poor accuracy of forecasts and work to build policies with the flexibility to adapt.

Driverless cars: a city of cheap robotaxis and the end of car ownership

CC image from the Museum of American History.

To date, most of the writing about driverless cars seems to focus on technology’s potential to make driving safer by eliminating collisions between vehicles. The thinking is similar to other auto safety improvements such as air bags or anti-lock brakes. These technological advances (endorsed by the US DOT) incrementally improve the safety of those driving – assuming that you are using a narrowly focused definition of ‘safety.’ However, an auto-centric definition of safety only works in auto-centric environments; in urban environments where cars and bikes and pedestrians are all sharing the same space, the definition of safety cannot solely focus on eliminating collisions between high-tech cars (more on this later).

Other articles predict that driverless cars mean the end of transit – an unlikely scenario that ignores the basic geometry of car-based systems and the capacity advantages of transit (imagine shutting down New York’s transit system and trying to fill that role with nothing but taxis – good luck). Furthermore, if driverless cars make vehicle automation easy, then it should also help drive down the costs for automating transit itself (among other potential uses) and unlock the benefits of automated transit.

Ownership:

The far more interesting scenario is one where autonomous vehicles completely upset the benefits of owning your own car. In the Atlantic Cities, Eric Jaffe questions the assumptions of car ownership in a world of driverless cars:

But we’re not so far away from this future that it’s too early to start considering what it might look like. As Matt Yglesias wrote at Slate in August, Google, the leaders in autonomous car technology, must have had some vision in mind to shell out $258 million for the car-slash-ridesharing service Uber: “ubiquitous taxis — summoned via smartphone or weird glasses — that are so cheap they make car ownership obsolete.”

Think about this world of shared autonomous vehicles for a moment. You wake up and get ready for work, and a few minutes before it’s time to leave you press a button and order an SAV [Shared Autonomous Vehicle]. The car has been strategically positioned to wait in high-demand areas, so you don’t have to wait long. You might share the ride with a couple travelers just as you share an elevator, or perhaps pay a premium to ride alone. Either way, you clear your inbox or read the paper during the commute, which is safer and more reliable than it used to be.

So, basically Robo-Uber. Or Auto-Car2go. Or Johnny Cab. This kind of behavior seems to be a far more likely outcome of the technology than the continued paradigm of each individual owning a car for personal use. Just as transit consultant Jarrett Walker talks about the importance of frequent transit service in providing freedom for users, the on-demand nature of the personal car is similarly freeing – but it required a) ownership of the car to ensure on-demand use, and b) the owner to actually do the driving.

Travel Behavior:

But what kind of changes in behavior can we expect from this shift away from car ownership? Writing at Greater Greater Washington, Nat Bottigheimer notes that planners haven’t even begun to address the issue. Jaffe’s article, however, cites some preliminary research from Austin on the impact of robotaxis.

Civil engineer Kara M. Kockelman of the University of Texas at Austin recently modeled the potential ownership change with grad student Daniel Fagnant…

The results offer an enticing glimpse of a world without car-ownership. Each SAV in the Austin model replaced about 11 conventional household vehicles. The roughly 20,000 people who made up this shared network, formerly owners of roughly as many cars, were now served by a mere 1,700 SAVs. Travelers waited an average of only 20 seconds for their ride to arrive, and you could literally count the number who waited more than 10 minutes on one hand (three). That’s to say nothing of personal savings in terms of cost (insurance, parking, gas) and time.

“Even when we doubled or quadrupled or halved or quartered that trip-making, we didn’t have big changes in our key variables,” says Kockelman. “This replacement rate, this eleven-to-one, those things were very stable.”

Kockelman is quick to point out the caveats. The biggest is that for all the savings in private car-ownership, vehicle-miles traveled doesn’t go down in the Austin model. In fact, it goes up about 10 percent. That’s because not only are SAVs making all the trips people used to make on their own, but they’re repositioning themselves in between trips to reduce wait times (see below). The additional wear also means manufacturers produce about the same number of cars, too, though each new fleet is no doubt a bit smaller and cleaner than the last.

So, a huge decrease in the total number of cars (presumably, with a corresponding decrease in parking demand, making the already-questionable logic behind zoning code parking requirements even more dubious) but an increase in the total vehicle miles traveled indicates that such technology won’t be a magic cure for congestion. It won’t spell the end of public transit in our cities. If the safety benefits accrue mostly to highway travel, it won’t change the need for safer streets where pedestrians, bikes, and cars mix.

The next question is on the impacts of driverless cars on cities and city planning.

The Unwinding: Erosion of our institutions and the concern that you picked the wrong profession

I’m working through my pile of books I collected at the end of the year. I just finished George Packer’s The Unwinding, a book telling the story of the Great Recession through the eyes of several main characters (factory worker turned organizer Tammy Thomas; civil servant turned lobbyist turned civil servant again Jeff Connaughton; truck stop owner turned biodiesel entrepreneur Dean Price) as well as vignettes of famous ones (Jay-Z, Oprah, Robert Rubin, Elizabeth Warren, among others).

The fourth main character in Packer’s story isn’t a single person, but the story of Tampa, Florida. Packer weaves several individuals together as a part of the storyline, including Mike Van Sickler. Van Sickler now writes for the Tampa Bay Times’ Tallahassee bureau, but reported extensively on foreclosures, mortgage robo-signing, and general planning and development issues in sprawling Tampa. Packer introduces Van Sickler, the journalist who once pondered a career change:

When he was covering city hall at The Palm Beach Post, he’d gotten deeply interested in urban planning – for a while he even thought about switching careers, until he realized that city planners had even less clout than reporters.

I had mixed emotions reading this. It’s a shot at my chosen profession that strikes awfully close to home, but also because it speaks to the challenges facing our institutions across the board – not just those involved in planning, development, and all things urban. It’s one of those uncomfortable statements we know to be true.

Packer’s focus on narrative means telling the story from the viewpoint of the characters, rather than offering an overarching analytical framework. This approach threw off Chris Lehmann (“a chronicle of the fraying of our productive lives that shuns cogent ideological or political explanations of the causes of our present crisis in favor of a thick narrative description of its symptoms”), accusing Packer of letting Robert Rubin off too easily for his role in the unwinding.

Lehmann clearly doesn’t prefer the subtlety of Packer’s method, using the perspective of different characters to critique someone like Rubin, rather than state so explicitly. Packer isn’t trying to be Chris Hayes (another good read, by the way) and lay out a theory of institutional decline. Even for Lehmann, however, adding Van Sickler’s character to the story helped provide some critical thinking:

Van Sickler’s story led to a high-profile federal indictment of Kim on money laundering and fraud charges, but the reporter wasn’t satisfied. He pushed against the complacent truisms about the mortgage meltdown that were being retailed by the other prominent outposts of his profession: “We don’t know why, we just got really greedy, and everybody wanted a house they couldn’t afford,” he says, summing up the prevailing consensus in the mediasphere. Van Sickler adds, “I think that’s lazy journalism. That’s a talking point for politicians who want to look the other way. We’re not all to blame for this.”

After Kim pleaded guilty, the United States attorney for Florida’s Middle District announced that more indictments, of far bigger fish in the mortgage food chain, were in the offing. They never came. “Where are the big arrests?” Van Sickler wonders. “Where are the bankers, the lawyers, the real estate professionals?” Packer finishes the thought for him, in a refrain his readers by now know quite well: “Kim was just one piece of a network—what about the institutions?”

Of course, urban planning isn’t separate from the unwinding. The foreclosure crisis, sprawl, and the decline of the middle class are all linked and all have spatial consequences. And these outcomes are all shaped by our institutions, often with substantial unintended consequences. Perhaps that was part of Van Sickler’s hesitation about a career change. What does that say about the planner’s role, both operating within our institutions and outside of them?

City Block

a work in progress…