Tuesday, January 29, 2013

Cause/Effect: Corridor Capacity Approach vs Network Capacity

I made a doodle.  It shows the two approaches to dealing with congestion.  They show how highways can approach and enter cities.  The difference is increasing CORRIDOR CAPACITY and NETWORK CAPACITY.
The top is transportation planners and their dogma.  The bottom is from sane people who understand that cities truly are the wealth of nations:

The difference is that transportation planners address density (and therefore congestion) they approach it as a problem of corridor capacity (it probably doesn't help that different hierarchy of roads have different jurisdictional oversight).  Since there is congestion, the only solution of course is to widen the road through the city, whatever property acquisition be damned, because the road isn't operating at level of service A.  What does level of service mean?  The traffic flow is smooth and uninterrupted.

Although there is a flip-side to this equation.  And that is the response to transportation infrastructural changes from the real estate market.  The St. Louis group fighting for a highway removal referenced a great line from 1912 city plan document for St. Louis, saying the point of city planning was "the art of arranging streets and public spaces that privately owned land might be put to best use."

I don't think there is a better way to put it.

On the other hand, there is the "context-sensitive" approach, which lets the network deal with the capacity and need for movement.  Where there is more congestion, the network gets more complex and more interconnected to add capacity while maximizing route choice, flexibility, and inherent intelligence built into the user.  You can adapt on a case-by-case basis and a route by route basis.  It also doesn't disperse real estate value away from where congestion is the highest by funneling traffic into one big, hot, stinky, dangerous corridor.  There is a built-in logic, order, and intelligence to it.

There is no such intelligence to modern traffic planning, no matter how many models or formulae are referenced.  The dendritic system concentrates the bad, while dispersing the good.  The reticulated, network approach concentrates the good, in densely connected, walkable areas while dispersing the bad (like high speed traffic or low intensity industrial uses to the periphery).

In studies for private clients, I have shown how a network of streets can lose virtually no total capacity by converting wide one-way streets to a more interconnected system of two-way, narrower streets.  Whatever capacity loss there is from lane reduction is mitigated by the fact that the sociofugal approach with bigger roads was operating at only 37% capacity at its highest traffic areas.  The reduction of lanes than allowed for increased parking and reduced right-of-way, thus yielding increased developable land for more efficient buildings on what were very narrow lots (again, due to overly wide roads).  Urbanism, it's all about the win-wins.  Best case scenario?  All of that road capacity does fill up, but it doesn't matter? Because the place is desirable, more walkable, and denser, thus allowing for increased resilience, which was what we were worried about.

Here are the by-products to the two approaches.  The choice is yours (well, not really.  But if you rabble-rouse enough, you might just get some say!):

1955 Highway Plan for Dallas

File:Dallas, Texas 1955 Yellow Book.jpg

Notice, there was no intention of a downtown loop or 345 in this original plan.  Oh, the temptations of free federal money and the chance to use it in ways Eisenhower lamented, like urban renewal in the most negative sense of the word.

This wouldn't have been that bad, except you can stop the Houston (45), Shreveport (80), and Texarkana (30) connections at the inevitable 635.  Or perhaps more realistically, loop 12 which is basically a highway at this point.  At that point, you transition the highway down in scale to surface boulevard and replace the corridor capacity with network capacity as intersection density intensifies to handle the extra capacity without 'throwing the baby out with the bathwater' as transportation planners eventually did.

Monday, January 28, 2013

DMagazine Column: Tear-Down Highway 345 in Downtown Dallas

Here's me at D Magazine (and on your news stands) on the potential value under and around Highway 345 in downtown Dallas.  As an addendum, I'd like to point out that yes, indeed there are more alternatives than the 2 I wrote about.  7 more, actually.  The differences are trivial and thus I felt they should be trivialized as shades of gray between constant minor repairs and complete rebuild.  Instead, we need the tenth option and we need to factor economics into our metrics:
The last consideration is the long-term impact that would result from tearing down IH-345. Here’s where the move would really pay off. Just as the system of freeways has shifted population outward, removing IH-345 from downtown would draw people into the city. It would reposition 245 acres so that it could be developed into walkable neighborhoods that could be home to 20,000 new downtown residents. Right now there is only $19 million in improvements on those 245 acres, and the city collects a mere $3 million per year in property tax revenue. By removing the highway, restitching the grid, and creating developable blocks, the city would see $4 billion in new investment within 15 years and generate $100 million a year in property tax revenue, based on our economic impact analysis. That’s enough in one year to implement the entire bike plan and build a new modern streetcar line from West End to Lower Greenville. Through land sales, TxDOT can generate some revenue to begin paying down its debt rather than adding to it. 

Thursday, January 24, 2013

IH-345 Downtown Presentation

Here is the presentation I gave last night to the Downtown Residents Council pursuant to adding a 10th option to TxDOT's feasibility study of complete facility deconstruction and restructuring of urban street grid:

Be on the lookout this week for February issue of D Magazine which will have a feature piece on 345.

Tuesday, January 22, 2013

Parks and Pops: of Demand, Supply, and Network Availability

Wick Allison wrote a piece yesterday about Woodall Rodgers Deck Park, aka Klyde Warren Park.  I'd link to it, but apparently there is something going on with FrontBurner's archives.  The gist of it was, there were a lot of people in the Arts District and more specifically KWP, and there was no provision of beer, nor enough other restaurants outside of the ever-present food trucks.  Dare we say, there wasn't enough accommodation to keep up with the demand through the integration brought about by KWP.  A little interconnectivity can go along way.  But is it enough?  And can the area support many more restaurants?

I was out there Saturday as well.  It was very crowded.  So crowded in fact, that waiting in line for the food trucks was undesirable (nor is there enough sidewalk space for these lines but that's tangential).  And yes, while I was out there, I was thinking, "man, I'd really like a beer."  We live downtown and since we do live downtown, we ended up heading back towards Main Street, about a half-mile walk that is made to feel even longer as it is primarily past parking garages and parking lots, all serving the various offices, the Arts District, and the all the drive-to park attendees on Saturday.

A half-mile.  This is the distance between pulse points, between signs of life.  Mostly because of the freeways allow people to commute in easily and therefore live much further away.  An infrastructural subsidy of sprawl.  That's perhaps the most interesting thing about KWP.  That's the very thing that makes it more interesting than a typical park is the very thing that limits is ultimate potential.  The freeway it covers (and is served by) is what creates dead zones around it.  Border vacuums, in Jacobsian terminology.

You don't find restaurants in border vacuums because there is no life.  Connectivity is limited by the wall that is the freeway, regional movement at the expense of local movement.  It is a sum subtraction on overall site connectivity.  Low connectivity, low life, little demand, no supply of accommodation in the form of restaurants or bars.

Yes, it's interesting. Yes, decking over a freeway is novel (but of course, an 18,000 person suburb of Bilbao, SP has a similarly sized deck park over a freeway).  But this is also the very fact that will limit it's long-term vitality in comparison to say, if it was an exact same size, scale, location as it is now without the freeway underneath it at all.

Wick acknowledges that yes, there will be a restaurant opening in the park in conjunction with the restaurant under construction immediately across the street.  If we don't think these are enough, supply not meeting demand, there are other opportunities nearby where that demand can be met.

 Above we see KWP and Bryant Park in Manhattan at similar scale, both centered within their respective aerials.

The obvious noticeable difference is in the street network immediately surrounding the parks.  As highlighted above, virtually every block in the immediate vicinity can support ground floor retail and are viable for restaurants/cafes/bars/coffee shops/etc.

Here are those very same things mapped.  They are fairly evenly dispersed throughout, a by-product of a very regular grid within a highly, densely interconnected place and therefore a highly dense city.

When looking at a similar map of KWP in the area, very few areas currently support restaurant life.  This is unsurprising, but fluid as this map (nor the real world and restaurant market) hasn't fully adapted or matured around the park.  After all, the park is new.  But it's also difficult to imagine exactly where these might occur that really populate the area.

Above, I've highlighted the obvious places where the land isn't spoken for and/or could be developed to support restaurants and retail.  It's fairly sparse.  It's mostly the undeveloped land and/or parking.  In blue, I'm showing areas that will naturally resist outdoor cafe life due to the road engineering as I showed in this map:

Cafes avoid conventional road engineering geometries because 1) the curve radii are so high that they encourage high speed traffic which is undesirable for pedestrians and cafe-goers to be near and 2) the dendritic nature clips the grid and undermines network connectivity.

The previous map showing the potential for restaurant space around KWP might very well be similar to its capacity for life and vibrancy in relation to other places like Bryant Park.

You might say, that is unfair, we don't have NYC densities.  Of course, this is an argument that underscores my point.  It belies the underlying dynamic that interconnectivity (global plus local minus the negative impact of global's physical infrastructural presence, which is nearly always negative) is the key determinant of population density (via opportunity and desirability) which then drives demand for accommodation (like restaurants) and decoration (more beautiful places and spaces).

Woodall Rodgers Highway is the underlying problem.  Yes, the park offers a degree increase of connectivity.  However, it only slightly mitigates the disconnective nature of the highway that creates demand for parking as well as the Arts District's mostly homogenous and land consumptive nature that prevents enough residential density from achieving levels necessary to provide stability.  It will be hard for KWP to keep drawing outsiders to the park at current levels.  Particularly as the visitors return home to whatever suburb and begin demanding similar accommodation closer to their home.

As I always say, what goes in the park is often not as relevant (as long as it's not bad, as in what used to be in Bryant Park that made it visually and physically impermeable and therefore less desirable) as the connections and vibrancy immediately outside the park in terms of the overall quality, character, and success of the park.  Connections and vibrancy that is minimized by the very thing the deck park simply covers up rather than truly fixes.  If we truly want our places to be world class we have to understand the dynamics that produce world class demand.  We can start by tearing out IH-345.  Just imagine the potential for parks with development around them:

Moses vs. Jacobs, Diagrammed Molecularly

Below is the diagram of a volatile gas, with disparate molecules with only the loosest of relationship to each other, bouncing about.  They are all the same molecule.  Just like in sprawl, every person is still a person, but the bonds between them are non-existent.  The volatility of which, is the critical defining characteristic.  This is the world of Robert Moses.  But the molecules sure can move fast!

Of course, if that gas is not fully contained the individual molecules will escape and with all likelihood will find more stable compounds to adhere to.  Below is a computer generated model of a diamond, the world's hardest known substance, a nice parallel here for resilience.  This is the world of Jane Jacobs.  The molecules are bonded together by relationship.  This was her street ballet.  You knew the butcher, the baker, and the candlestick maker on your street and they all knew the neighborhood's children.  They take some measure of responsibility for the children, because the neighborhood's children are their children.

What transportation planners and engineers don't understand when they objectively believe they are serving the city and its citizens as the city currently exists (there's demand for driving, we need to provide more supply, bigger roads!).  Unfortunately for the rest of us, DOT's are more like the scientists who unwittingly transform the subject they are observing.  However, they are not only observing, they are also fundamentally transforming how the city operates with each new highway and dendritic network, systematically disrupting the bonds of neighborhoods that define resilient cities.  But hey, we can all drive faster!  Until that road is invariably choked with traffic or we run out of the ability to maintain the excessive infrastructure.  Whichever comes first.

Wednesday, January 9, 2013

Selling Taxes

Virginia Governor is pushing for a repeal of gas taxes to be covered by a rise in sales taxes.  This is covered a few ways by the DMN, none worth reading, but you can find them if you so want.  That is, unless you really enjoy a condescending tone towards "Granny" and presumably anybody else that doesn't or can't drive.  Since gasoline taxes are intended as a form of user fees to help roads pay for themselves (which they don't fully), and Granny doesn't drive, why should Granny pay for others to drive.  That would make a lot of sense, if the writer than didn't super cleverly 'pull a fast one' and say everything else Granny needs is tied to roads.

I have no idea what the purpose of including this to the article was, considering the article wasn't about no longer funding roads, but funding in different ways.  Robbing Peter to pay Paul.  All it accomplished was announcing a lack of understanding that dependence on cars and roads is a problem.  But otherwise, yes.  Infrastructure must be funded.  And we have too much of it and too much burdensome infrastructure on top of it.  There is the real issue.  That might be too complicated.

Assuming for the moment the Governor's intentions are not a way to circumvent gas taxes often being dedicated to roads and roads only and generate the necessary money for infrastructure through a general fund which can be used in a broader spectrum of solutions to the real problems.  That might be interesting, but it would also be worrisome if those weren't the intentions of an ever changing leadership.  The benevolent dictator is the best form of governance only until that dictator steps down.  What's next?  And are actually a way to fund a legitimate problem, dwindling money for roads and too many roads, within the context that he doesn't understand that we are horrifically over-infrastructured and incredibly inefficient in the design of this infrastructural networks, ie grids are empty and disconnected while highways become increasingly choked.

The Governor of Virginia's worry is that with more fuel-efficient cars, people will be buying less gas therefore the money has to be found somewhere.  Oddly, the state of VA taxes alternative fuel vehicles to also cover this gap.  This tells you they clearly don't get the crux of the problem since there goal is more infrastructure for more driving, not efficiency of movement, resource allocation, and the spatial relationship of the economy.  They just want more money and more roads.  VDOT must be in his ear.

Let's think about what will actually happen if gas taxes were dropped and shifted as a revenue source over to sales taxes (isn't buying gas effectively a sale?).  Let's also assume this isn't an effort to jumpstart spending by moving revenue generation from a captive market (coerced driving) to something more discretionary, general sales.  That makes a lot of sense theoretically and politically, but it doesn't do the job of covering the funding gap since discretionary spending suffers from dynamic fluctuations.  Cities and states dependent upon sales taxes were rocked by the recent discretion.  How would this be better and more dependable?  Again, only in  the terribly misguided context of 'build more road capacity!'

Furthermore, dropping gas prices would very likely increase driving.  By increasing driving, you increase the demand load, ie stress, on the infrastructure that is already under so much stress as to reach the breaking point.  Ultimately, these are fairly complex issues politically and economically, even if we had all the information from the governor's office to know their thought process.  What really matters most is whether the public has confidence in their elected leadership and whether the governor and his DOT actually understand the real issues.  Unfortunately, I suspect the answer is no to both questions.

The only way it makes sense is if the revenue generation was put towards reducing automobile dependence, but it surely isn't.  If that was the real goal, we'd just shift the funds from gas taxes to these alternatives the way London does with their congestion charge.  But London actually has a plan and a purpose it is working towards.  A more enlightened one than "more money, more growth, more of the same, more stupidity."

Tuesday, January 8, 2013

Conflict Zones: A Simple Study in How Increasing Vehicle/Pedestrian Conflict Makes for Safer Places

This felt necessary.  In an email discussion somebody about real and perceived safety in urban, suburban, and exurban areas, probably better classified as walkable and unwalkable places, somebody mentioned that NYC is experiencing record highs in pedestrian fatalities this year.  Up to 170.  Now this is mostly due to increased pedestrianization and the competition for space between new pedestrians and existing vehicles on roads in NYC that are systematically being made more safe.  One by one.

The conflict is inevitable, but ultimately the goal is to decrease the need and danger posed by the automobiles over time.  In that sense, there are both long-term goals, but short-term increases present even though the numbers are higher than ever.  If the amount of pedestrians is increased, the number of conflicts between cars and pedestrians will be increased as well until the cars are slowly decreased in the equation.  With this understanding, it's entirely possible that NYC's rate of pedestrian fatalities could be going down despite the total number going up.  This is fairly hard to figure since most fatality rates are calculated quite simply:  total deaths (by type) divided by total population (in 100,000s).

To fully calculate this we would have to have NYC's commuting rates by mode, by year, or at least decade.  I haven't found those yet, but I'm sure they're out there.

The larger point I want to make is about NYC's seemingly high pedestrian fatality rate in comparison to other places.  All things NYC seem high by scale.  It's a bigger place, with more people, therefore there will be more of just about everything.  Over that year time span where NYC lost 170 pedestrians in traffic accidents, Dallas is on pace for about 72.  170 is greater 72 (triangular dots meaning therefore) NYC is totes way more dangerous than Dallas!!!11!

These numbers begin to slowly fall apart when you 1) calculate the simple rate then, 2) really fall apart when you start looking at representative number of conflicts between pedestrians and vehicles.  Let's do so shall we...

Population (100,000)
App. Annual Ped Deaths


Perc. Ped Commuters

Ped. Adj. Fatality Rate

Perc. Ped+Transit Commuters

Adj. Total Ped. Fatality Rate

This is a table.  It includes population, approximate annual pedestrian fatalities, and most importantly commuting rates by mode to represent an abstraction of conflict points.  And this is different than the theoretical conflict points of traffic engineering which draws lines of theoretical movement and every time they intersect, voila! conflict point.  It doesn't say whether there are actually vehicles or pedestrians there (usually, it's been engineered in a way that no pedestrians would be there, therefore SAFER! Amirite?!).

When factoring simple rates of pedestrian fatalities by population, we see that Dallas has nearly 3x more pedestrian fatalities.  And we're all like, duh! People drive more.  But because people drive more, they also walk less.  So that means even less conflict points.  If there are less conflict points, it would theoretically be more safe.  Not so.

When factoring the population only for pedestrian commuters, the rate of pedestrian fatalities rises in Dallas to 17x that of New York.  Taken to an even further extreme to factor transit commuters, since there is nearly always pedestrian activity at both ends of a transit commute, this number balloons to 51x the pedestrian fatality rate in Dallas as opposed to New York.  Therefore, we can deduce that increased conflict between pedestrians and vehicles yields a safer overall environment even though there is still the possibility of danger evidenced by the 170 pedestrian deaths in NYC this year.

So what do we have to do?  We have to get more pedestrians.  And the only way to do that is to build street/block structure and infrastructural networks that are conducive to walking.  And in hollowed out sun belt cities that also means leveraging the real estate market to favor infill development rather than sprawl (and much of that has to do with the bones of the real estate market, the shape of the infrastructural network).  And the only way to do that is to replace a good portion of the dendritic highway/arterial network with a multiply interconnected, reticulated grid-like system.

Monday, January 7, 2013

On Congestion Taxes and the Sun Belt

Congestion taxes are the latest in a long line of magic bullets proposed to solve all city problems.  One of the clear differences between congestion taxes and other oft-cited magic bullets (stadiums, convention centers, starchitectural public monuments, casinos, etc), is that there are actually clear, demonstrable examples of success around the world, particularly in London and several Swedish cities such as Gothenburg and Stockholm:

The theory is that the vehicles entering the core are effectively taking up space, polluting, degrading the public environment, and through their presence are stultifying the internal combustive socio-economic activity that defines cities, so they must pay to offset that cost they impose.  It is quite logical provided the context is appropriate.

New York City has already shown the challenge politically in implementing a congestion tax even though in all probability would've been extremely beneficial in NYC.  However, when I read or hear people suggest congestion taxes without offering the context of when and where, let alone in Sun Belt cities, I feel compelled to point out how catastrophic they would be in the Sun Belt.  What we have to understand is that whatever cities are doing elsewhere, often don't apply here.  Sun Belt cities, though governed by similar forces, have become entirely different organisms than cities of most of the rest of the world.

Congestion taxes have worked where they have (and would've worked in NYC) because demand is still high in the core and would be high enough to sustain a given rate just to enter the core in a private vehicle.  In the sun belt, where the core is hollowed out by the infrastructural system, there isn't a similar demand.  If implemented in a place like Dallas, it would only halt any shifts back towards the core and reverse the inward movement of the real estate market.  People would effectively say, "why would I need to ever go down there again?"

As a basic formula, if you want to know whether a congestion tax is appropriate in a city, just compare the cost of parking (here's a telling overview), ie, are businesses or customers shrieking, "OMG we can't lose our free parking!!!!111!!! ?"  It's very expensive in the places where congestion taxes have worked successfully because space is at a premium.  Not so coincidentally again, the congestion tax decreases demand for parking thus dropping parking costs to the point where the space for parking can be repurposed to something more invaluable.

In effect, a congestion tax in the sun belt would have the opposite effect of what is intended, to improve the real estate market in the core, maximize livability, and land use efficiency.  Instead, it would be the final nail in the coffin.  Rather than pursuing more inappropriate "cut-n-paste" urbanism, the answer to shifting the real estate market back towards the downtown core is in the highways, more specifically the land occupied by them.

Drunk Driving Fatalities

The Morning News has linked to an excellent graphic depiction of the deadliest and safest cities amongst the 25 most populous cities proper:

This is interesting because it lists not only alcohol related traffic fatalities per capita and per accident, but also total traffic fatalities per capita, allowing us to see a potential relationship between cities.  However, we can only speculate why some are deadly due to alcohol, but not deadly overall, like Chicago.  What is most telling is the pattern of cities that are consistently at the top (or bottom) of all three lists.  In the case of deadliest, it is the sprawlingest.  The cars built for the car and car only.  The places we like to pretend the car is king because of preference rather than policy and infrastructural coercion.  Dallas, Phx, and Houston make the top 6 in all three lists.  The only cities to register.  A shame Atlanta doesn't make the cut population-wise since it has been so thoroughly hollowed out we can't assess it similarly.

Don't say I didn't try to warn you:



Blame the driver or drunk driver all you want, prohibition proved people will still drink.  Blaming these deaths solely on individual responsibility is to be blind to the patterns clearly illustrated by the chart above.  It's whether they can walk from where they drink that matters.  And not so coincidentally, walkable places naturally concentrate activity which in turn concentrates cab activity and the accessibility to cabs.  There is blood on the hands of the city builders of the sun belt.