Questionable Data, Narrow Vision Still Mar Sheridan Study

“We realize that we can’t just look at the highway facility itself; we need to look at the impact of a highway through the community it runs through, it needs to focus on not just moving traffic.” – NYSDOT Region 11 (NYC) Director Phil Eng on the Bruckner-Sheridan Interchange project,  New York Times, July 12.

Few projects demand the type of broad vision described above as much as the Sheridan Expressway in the Bronx. For over a decade, community residents have asked state officials to ease the burden on the South Bronx by removing the 1.25-mile Sheridan and using the footprint for open space and development. But despite Director Eng’s words, last Tuesday’s NYSDOT stakeholder’s meeting on the Bruckner-Sheridan Expressway, the first in 2 years, was a live illustration of an organizational silo at work.

The meeting was convened for the presentation of the Department’s traffic “micro-simulation analysis” results, a process in which future traffic patterns and volumes are projected for each of the project’s alternatives.  Besides a required “no build” alternative, NYSDOT is weighing two “build” alternatives, one which would remove the Sheridan (1E) and one which would keep it (2E).  Aside from the fate of the Sheridan, the two are nearly identical, each creating a new interchange from the Bruckner to direct trucks to the Hunts Point food markets and industrial areas and a new alignment on the Bruckner Expressway to widen a bottleneck over the Bronx River.

Projected to year 2030, the Department sees skyrocketing traffic volumes under any scenario, generally projecting higher volumes on local roads if the Sheridan is removed. These latest results appear quite specific, but need to be taken with a whole shakerful of salt because they are based on the same traffic modeling process and underlying data which the Southern Bronx River Watershed Alliance concluded was “junk science” after hiring Smart Mobility, an impartial out-of-state consultant, to review the state’s data. That 2007 analysis found basic errors, faulty assumptions, and a fundamental mismatch between the project and the traffic model used to analyze it.

Both then and now, the project team used the NYMTC Best Practices Model, or BPM, for studying traffic patterns and projections.  The Department used local traffic counts to calibrate the model, but the BPM’s design and underlying assumptions skew the latest results in the same way as the earlier numbers.

The BPM is a regional model, one which Smart Mobility called useful for analyzing “big picture land use and pricing assumptions.”  However, “it is of more limited use in evaluating the different traffic impacts of the [Bruckner-Sheridan] Build alternatives, because the differences are small relative to the accuracy level of the model. Use of the BPM for screening the alternatives is appropriate, but… the modeling is too coarse to calculate significant differences in future traffic impacts between the alternatives.”  Yet this is precisely what NYSDOT did and presented to the public.

Even if the BPM were an appropriate model to apply to the study area, garbage in still equals garbage out.  Our report also found that “about half of the purported benefits [of keeping the Sheridan] result from model coding errors rather than any real transportation effects.”  These included one-way streets mapped in the wrong direction and ramps coded with incorrect capacity numbers. The BPM also assumes that traffic steadily increases with population, unbounded by physical capacity constraints, producing “an implausibly high level of future traffic in the study area.”  In fact, the magnitude of the projected traffic growth dwarfs the differences between the remaining alternatives.

Because of the model’s uncertain conclusions and the errors underlying the Department’s projections, the decision to remove or retain the Sheridan should be based more on the potential community benefits of each alternative — including, but not dominated by, traffic considerations.  Unfortunately, study of the environmental, recreation, and economic benefits of a Sheridan removal is not part of NYSDOT’s plans.

A Cost-Benefit Analysis, Without Benefits

Tri-State and the Alliance have proposed and advocated for the Community Plan to create over 1,200 new units of affordable housing and over 700 permanent jobs in the Sheridan’s footprint. Such a plan would provide the surrounding neighborhoods, those with among the highest asthma and obesity rates in the country, with parks, river access and community space.

But that’s not even close to what NYSDOT will study as it prepares a Draft Environmental Impact Statement (EIS). “You just lose the Sheridan,”  Project Manager Guy LaMonaca said in describing the project team’s anticipated approach to the removal. He added that the Department would study that alternative as if the Sheridan was simply fenced off to traffic.

When challenged to ascribe value to the land in the Sheridan’s footprint, project officials claimed that their hands were tied.  Unless another governmental agency presented a “commitment” to a “concrete plan” for developing the area, the Department could not consider future land use scenarios in its analysis of the alternatives.

In fact, EIS’s do routinely study the potential and projected impact of projects on land value. Though it would be preferable to analyze the removal alternative with a fully conceptualized plan like the Community Plan, the value of developable land can be derived from the land values and uses in the  surrounding neighborhood, a Federal Highway Administration official at the meeting admitted.  Public parkland likewise has quantifiable value.

By law, NYSDOT is required to evaluate the project in a diverse number of areas that includes “Land Use and Social Conditions,” “Economic Conditions,” “Cultural Resources,” “Visual Resources,” and “Environmental Justice.”  As the Department would have it, the EIS would simply be a cataloging exercise of current conditions in each of these areas.  However, state and federal environmental law require the Department analyze the “impacts” of each alternative in these categories – an exercise that requires a projection of future impacts.  By dismissing the idea that the removal could provide any benefits to the surrounding communities, NYSDOT would make it impossible to conduct a balanced weighing of alternatives.  Such an inadequate analysis would be a waste of time and resources, and could open the project’s EIS to legal challenge.

16 Comments on "Questionable Data, Narrow Vision Still Mar Sheridan Study"

  1. NYSDOT will not see a situation where reduction of built capacity will provide any benefit. Namely, the traffic modeling process is based on rates of flow and congestion reduction, not community benefits.

    So, let’s take a step back. Instead of pushing full bore into a demapping and eventual removal of the Sheridan, perhaps the community could advocate and organize a Sunday closure – ala the Summer Streets idea – and sponsor a community walk/bike festival that would provide a day of respite for the neighborhood and hopefully demonstrate to NYSDOT that closing the Sheridan will not result in carmageddon.

  2. There were a few minor errors identified with NYSDOT’s previous work, but this misrepresents the facts.

    1) Some of the so-called “errors” were mistakes by the advocates, not NYSDOT. The single largest issue in question – the capacity of the ramp connecting the northbound Deegan to the Alexander Hamilton Bridge was coded correctly by NYSDOT as a single lane. Even though the advocates provided a conveniently-cropped picture that showed (part of) the ramp with two lanes, it merges to a single-lane, resulting in a single lane of throughput capacity. (The other errors were largely inconsequential…)

    2) Even after the advocates “corrected” the assumptions in their favor (doubling the capacity of their proposed diversion all the way around the South Bronx via the Bruckner-Deegan), it still did not change the basic outcome. Traffic performed worse without the Sheridan. Even with unduly favorable assumptions for their proposal, it performed worse. Not as much worse, but still worse.

    There are also problems with the idea that NYSDOT would evaluate “benefits” for other “projects” that have never been defined at even an acceptable sketch level. There are legal and good planning reasons not to base decisions for a project on separate projects that are not committed. Not only is the housing scheme not committed, the advocates have spent a decade drawing ever-more-elaborate renderings and going 3D flyovers, but have not done basic back-of-the-envelope figures or identified any source of funding to have any confidence that environmental remediation would be performed, that the affordable housing could be financed at the low rent levels they are promising people in the community, or that the substantial infrastructure needed to support the large-scale development they propose could be installed.

    With no plan to evaluate, it would be highly unprofessional for the planners at DOT to assume any benefits for a whole set of projects under the control of others that may never happen, and may not even be feasible.

    Additionally, these advocates insist on taking credit for “benefits,” while refusing to recognize the socioeconomic and environmental justice costs associated with shutting down the existing light industry in the area and shifting those activities to other locations (invariably located closer to vulnerable populations!).

    Unfortunately, it seems the community advocacy planners indulged in too much fun campaigning, calling professional planners names and making promises about results they couldn’t actually support with their analysis. They simply didn’t attend to the actual planning work. Now they want the DOT planners to take the blame?

    Don’t get me wrong; I fully endorse community advocacy as a form of planning. I fight to try getting it more resources, and entirely understand how difficult it can be without funding. Nevertheless, none of that excuses poor planning. Demanding that NYSDOT included benefits for uncommitted, potentially unfeasible, independent projects, and that it simultaneously ignore the costs and community impacts of those very same projects, is certainly poor planning.

  3. Additionally, the consistent lack of coherent discussion is highly troubling.

    It is shocking to see someone cite “the highest asthma… rates in the country,” as a core problem, and then turn around and say that making traffic worse is an acceptable outcome.

    The people who make such statements either do not understand the issues on a very basic level, or they’re not being entirely forthcoming about the real tradeoffs that are involved. Either way, it makes it very difficult to support a project based on their arguments.

  4. Jay, you’re talking about the projected ~2.5% difference in area traffic 20 years in the future, right? (This is Table 1 in the Smart Mobility report – the “uncorrected” table using NYSDOT data only.)

  5. Jay,

    The model ignores obvious, common-sense points, like the fact that motorists have a certain tolerance for congestion. If the model projects a worsening of traffic, chances are some of those purported new motorists will find new routes or avoid driving altogether, rather than sitting the extra minutes in traffic. To assume that every driver’s patience is infinite is one of many problems with the NYS DOT’s model. Furthermore, new open space (even if simply left to revert back to nature) will mitigate the miniscule effects of any new air pollution.

    Even more importantly, removing the Sheridan would send a signal that people who live in the South Bronx are not less important than people who simply drive through it, and that they also deserve a certain quality of life that has been denied to them for decades. It is this admission that the DOT is so afraid to make – that city living is normal, acceptable, and even in some cases desirable. Because once it admits it, DOT will have less and less to do and begin to lose its influence.

  6. Boris,

    I’m not an expert on the BPM, but I don’t believe that is correct.

    The BPM goes through a whole microsimulation process that changes assignments of not only routes and mode choices, but also considers different potential destinations. Congestion is considered in particular with a “vehicle delay function,” which is explained in much more detail here:

    What the model shows is that after everyone has found a better route, changes mode, or shifted their destination to a more tolerable trip, there is still an increase in the level of congestion.

    As for the air quality argument, there is no way I can see to make it remotely relevant. But I give you credit; at least the greenspace angle has some sort of logical credibility.

    I just don’t believe the affordable housing buildings are really going to absorbe that much in emissions. Most of the actual Sheridan alignment would become buildings, in the community scheme, rather than parkland. Most of the true parkland (and the greenway) will be there with or without the Sheridan.

    Even with green roofs (which add to the expense of a project we don’t know to be viable without that added cost…), I doubt the net reduction in pollutants would match the increase from worsening traffic, especially when you consider that whatever small amount of additional greenspace would be far removed from the areas along the Bruckner and local intersections where the emissions would actually be increasing.

    I agree that the people in the South Bronx deserve a better quality of life. Perhaps we should begin by making sure we don’t inadvertantly make it worse with poor planning that shifts traffic from an area separated from their neighorhoods to the intersections where they’re riding their bikes, trying to cross the street, and don’t need idling cars honking below their living room windows.

  7. As I remember, Andrew Cuomo supported Sheridan removal many years ago. I doubt if he will bring it up as a campaign issue, but if he is elected governor, he may be able to tame the bureaucracy.

    There are obvious mitigations to the impacts that the study identifies. If some traffic is diverted to local streets, you can add speed humps to slow that traffic – which can actually make the streets safer than they were previously. Has the study identified these impacts?

    Jay prefers having the traffic separated on a freeway. I and most people would much rather have a park within easy walking distance of my neighborhood and have a bit more traffic on the local streets – if there were mitigations to make sure that traffic was slow and safe.

    In addition, it is doubtful that this spillover traffic will materialize at all. The projections of constantly increasing traffic are obviously mistaken: world demand for petroleum is growing faster than supply, and gas prices will clearly go up and reduce or reverse growth in VMT.

  8. I am knowledgeable about BPM, but not the specifics of the model runs done for this study. I’ll just say that (1) Smart Mobility is right that its use to study local area effects is often “junk science” in that the model is not intended for this purpose; and (2) Jay is also right in that the model accounts for how individuals’ mode and destination choices respond to changes in congestion/accessibility. But just because the model accounts for this at a regional scale (e.g. the introduction of a new transit line) doesn’t mean that it does it well in this particular case. It’s only as sensitive as the underlying travel surveys allow it to be.

    More recent research shows that these models typically overstate the congestion that results from reductions in network capacity:
    Hopefully our transportation models can evolve to incorporate this research more effectively. In the meantime, it sounds to me like NYSDOT is being unnecessarily alarmist.

  9. Charles Siegel would have a better point if he were correct that there couldn’t be a park without removing the Sheridan. But that simply isn’t true.

    Starlight Park is already right there, with completely safe, grade-separated access. It is already being expanded (at great public expense to remediate the soil). There are plans to develop a complete bicycle greenway along the river – all without the need to remove the Sheridan.

    Perhaps we can get this discussion to the point where we can honestly discuss how much (or marginally) removing the Sheridan would actually improve access to the riverfront park. The railroad will still be there. The portal and long stretch where the 6 train transitions from subway to elevated will still be there. And (unless a lot of jobs are disrupted) a lot of light industry will still be there. Removing the Sheridan doesn’t do near as much as the overheated rhetoric would have you believe.

    Suggesting the only way to provide park access in this area is by removing the Sheridan simply is not true. It is rather discouraging that people who should know better keep making that suggestion.

  10. Perhaps we can also get the discussion to the point where we can honestly discuss how much removing the Sheridan would improve the park itself.

    The current park does not look very good to me – and it does not look very good to the people who live in the neighborhood, which is why they want to expand it.

    So, I will revise my previous statement to say:
    “I and most people would much rather have a SIZABLE AND ATTRACTIVE park within easy walking distance of my neighborhood and have a bit more traffic on the local streets – if there were mitigations to make sure that traffic was slow and safe.

  11. Also: The railroad tracks will indeed still be there, and they will always make access difficult to the riverfront.

    By contrast, the new parkland would be on the same side of the tracks as the neighborhood, so there can be direct access to the new parkland at every intersection. The new parkland would also be large enough to have room for playing fields, lawns, and other recreational facilities that the neighborhood can use.

    The example of Riverside Park shows that this sort of park overlooking a river can be attractive even where there is no direct access to the riverfront.

    There is obviously a great benefit to direct access to a park with space for different forms of recreation, rather than roundabout access to a narrow riverfront.

    The issue is not “how much (or marginally) removing the Sheridan would actually improve access to the riverfront park.” The issue is creating a new parkland on the neighborhood side of the railroad tracks, which would be very easily accessible.

  12. Yes, let’s talk about what Starlight Park needs, and what you can actually get with the removal of the Sheridan.

    But first, let’s make sure we have a clear picture of the context. Charles Siegel is again playing a little fast and loose with the facts. There are residential communities not-too-far from both sides of Starlight Park, but the more proximate neighborhood is the one separated by the railroad tracks, which sees no improvement whatsoever from removing the Sheridan, but would have to deal with traffic impacts. (To the west, the community is further separated from the park by existing light industrial uses.)

    Both communities currently have grade-separated access from the 174th Street Bridge. This allows residents from the west, in particular, to get to the park without crossing West Farms Road, and it obviates the need to walk through the industrial area.

    There is access from the south from Westchester Avenue, but this requires navigating some difficult intersections, and then walking through a stretch of industrial uses. There is no access from either side in the vicinity of 172nd Street, nor from the north.

    It is true that Starlight Park is rather unattractive, but let’s be clear about why. The size is not the real issue. Starlight Park is very similar in configuration to Concrete Plant Park, which is popular and was opened to great acclaim.

    Much of what Starlight lacks is any amenities, maintenance, or even basic design. Even though it runs along the river, visual access is very limited. Of course, it is undergoing environmental clean up and being enlarged right now, and we should expect, and demand, a better park when the new section opens. It also currently lacks the north-south access that would allow people to travel through the park and enjoy it.

    Of course, each of these problems can be solved without touching the Sheridan. Design and maintenance of the park do not rely on removing the roadway. Plans for the greenway will improve access over the railroad tracks from the east, allow people to cross the river and connect to the north for full connectivity through the site and far better visual access to the water.

    Anyone familiar with The Bronx, or New York City in general, understands that there is never enough Parks budget to maintain the parks we have – so adding more parkland can only be expected to add more space that won’t be adequately maintained, and further drain the resources for all the existing parks. If we can accept that the quantity of parkland is less critical than the quality and accessibility of the parkland, then we could start looking for solutions to the real problems.

    If you want to look for a capital-intensive project that would meet these goals for better park access, as well as improving transportation in the neighborhoods (rather than making it worse!), you might consider building a bridge at 172nd.

    A new bridge would allow people to have another point of access to the park. For people who want to travel between the neighborhoods, they could simply walk or bike straight across without having to go down the hill and back up on the other side. It would keep residents separated from the industrial uses, preserving jobs while improving the connection to the park.

    It would also allow 174th to be converted to a one-way street, which would do several positive things. It would spread and calm the traffic more. Of enormous benefit, it would simplify the horrendous intersection at Boston Road, which is a nightmare for pedestrians using the subway. A lot of roadway space on 174th could be reprogrammed to create a fully-separated bike lane, and the sidewalks could probably be widened with better greenery as well. Similar treatments could be provided on 172nd.

    Such a bridge would add a meaningful connection between the two neighborhoods. Removing the Sheridan would not. Such a bridge would provide more access to Starlight Park to the neighborhood to the east. Removing the Sheridan would not. Adding a modestly sized bridge of this type, even with the architectural statement this community deserves, would be less expensive than removing the Sheridan.

    Of course, you end up different places depending on where you start. If you’re trying to improve access and reduce the impacts of traffic on a neighborhood, you can find solutions that improve the quality of life by building a new landmark. If you start with a crusade against highways, you end up with a list of marginal benefits that have to be exaggerated, and a plan that would ultimately make transportation worse for everyone.

    I continue to see Tri-State Transportation Campaign acting out of character on this issue, especially as a group intended to promote improvements in transportation.

  13. I agree with Jay’s proposal to build a 172nd Street bridge. Not only would it improve access to the park, but it would relieve congestion on 174th Street. In addition, 172nd Street would provide a direct road to Boston Road without turning at Hoe Avenue, then using 173rd Street to reach Boston Rd and Crotona Park.

  14. “Anyone familiar with The Bronx, or New York City in general, understands that there is never enough Parks budget to maintain the parks we have – so adding more parkland can only be expected to add more space that won’t be adequately maintained, and further drain the resources for all the existing parks.”

    But, of course, there is so much spare money available for maintaining roads that we can add roads and bridges without worrying about budget.

    This statement by Jay implies that we should never add more parks in New York.

    If you start with a crusade against parks, then you are bound to come to irrational conclusions.

  15. Commentator | July 26, 2010 at 5:47 pm |

    People need to take these simulations with a gigantic grain of salt. If we could predict traffic 25 years down the road this well, we wouldn’t have congestion in some places and wide open roads in others in the first place!

    The best way to find out what the effect of road closure is is to try in out in real life: close the road for a month and see what the effects are.

    In any event, what’s the confidence interval on these estimates? I’m certain that it’s larger than the differences given by the simulation; in other words, even if the assumptions are all 100% correct, and the projection technique holds water, the error in the estimates in likely greater than the actual differences between them.

  16. Charles,

    Even on your terms, your statement doesn’t hold up. The NPV cost of constructing and maintaining one modest bridge at 172nd would surely pale in comparison to the extraordinary costs of removing the Sheridan (demolition, maintenance and preservation of traffic, environmental remediation, changes in highway signage, etc.) combined with the ongoing O&M for whatever ultimately replaced the Sheridan. Moreover, a case could clearly be made for a Transportation Enhancement grant for a bridge at 172nd, whereas there’s no chance you could qualify for transportation funding to remove a roadway when the modeling demonstrates that it would make transportation worse.

    But let me reiterate the real point I was trying to make (somewhat sloppily I’ll admit):
    Adding additional parkland, without solving the accessibility problems, would only strain the budget for very little public benefit.

    What I discussed was a focus on solving the accessibility needs, in ways the “plan” to remove the Sheridan does not. There were specific examples you chose to ignore, opting instead to take a selective quote out of context. Perhaps you think the smoke and mirrors will distract from the fact you don’t even have the basic geography of the site correct?

    When you defend this scheme to remove the Sheridan to make a “park,” why can’t you talk about the lack of accessibility from the neighborhood to the east? Why won’t you recognize that residents from the west would have to walk through an industrial area to get to the park (unless they use the 174th Street Bridge, which is already there)? Why don’t you recognize that there still won’t be any connectivity between the neighborhoods to the east and west of the Sheridan?

    The bottom line is that the parkland you propose would not be particularly useful parkland, but would come at a huge expense, both in dollars and cents and in quality of life every time a minor accident on the Cross Bronx flooded whole neighborhoods with traffic that would have been confined mostly on the Sheridan. There are other opportunities in this area that would reduce traffic impacts, expand the network for non-motorized modes, and extend better transit service to the most underserved areas that generate so many of the auto trips.

    Unfortunately, some people just insist on removing a highway rather than considering other alternatives, no matter what it would cost the community.

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