Saturday, May 28, 2016

Expected Loss of Residential Property Values due to the Lafayette Connector

Source: Lafayette Consolidated Government,
Metropolitan Planning Organization
The old joke asks "What are the three most important factors in determining the value of a house?" The realtor answers "Location, location, and location." There is clearly some truth in this joke, and location close enough to an interstate highway to see it or hear it or smell it is clearly a negative.

The area of impact of the I-49 Connector project has been wordsmithed by proponents into the project's "area of influence." The attached figure outlines this area of influence as defined by the Metropolitan Planning Organization (MPO). The question I'm asking here is "How much will home values within the impacted zone be depressed if the I-49 Connector project is built?" This is a vitally important question because for many residents their home is their greatest financial asset.

Residential property values of homes located near interstates are reduced because of noise, pollution, and appearance of the roadway. Taken together, these impacts on appraised value from being located close to an interstate are called interstate proximity stigma.

How much would the proximity stigma of the I-49 Connector reduce property values? Research looking at home sales from 2002-2005 within one mile of Interstate 90 in Seattle (Kilpatrick and others, 2007) confirmed the anticipated result - home prices closer to I-90 were lower, and prices more distant are higher. Under the researchers' model, a home 0.4 miles from the interstate lost 4% of its value relative to a comparable home one mile from the roadway; a home 0.1 miles from the roadway lost 13% of its value. Consistent with these findings, Clark and Herrin (1997) found a 10% reduction in value when homes were located within 0.25 miles of an interstate.

Thus, it is concluded from these studies, as well as common sense, that home values within the zone of influence would be reduced after construction of the I-49 Connector. A 10% reduction in value is a reasonable guess based on the cited research. Moreover, it is reasonable to further assume that houses in the impacted area will typically be harder to sell and will stay on the market longer than houses not suffering the interstate proximity stigma.

D.E. Clark, and W.E. Herrin (1997) "Historical preservation districts and home sale prices: Evidence from the Sacramento housing market" The Review of Regional Studies27.1 (1997): 29-48.

Kilpatrick, J.A., R.L. Throupe, J.I. Carruthers, and A. Krause (2007) "The Impact of Transit Corridors on Residential Property Values" Journal of Real Estate Research 29(3):303-320.


  1. This article and research was done for ABOVE GROUND interstates. Lafayette, and many cities around the country, have moved beyond this old truth to NEW ideas and great design to develop new truths that fix old problems. Being FOR a cut & cover option OR the Teche Ridge Route is OK. Building the cut & cover design will also accelerate our ability to remediate the pollution along the rail road tracks, minimize rain water run off, create land to be developed and redevelop our neighborhoods along the urban corridor, REconnect the areas on both sides of the railroad tracks and much more. Please consider supporting the cut & cover option as LAFAYETTE'S best way by far to fix decades of problems while stimulating our economy...

  2. Robert,
    I give you a sincere thank you for reading my post and taking time to comment.
    I have found no studies looking at depressed or covered interstates' impact on property values, but I did see a study looking at the impact of a tunnel, and it had similar findings of home property values falling next to the tunnel. Anecdotally, I have heard negative comments from someone who lived near a depressed interstate in Texas. Another problem with this depressed and covered interstate concept is that it blocks pedestrians at the rail tracks with a retaining wall. This again gives us a divider rather than a connector.

    I am skeptical that the depressed plan can move forward because of the contamination at the site. I fear this is a bait and switch being pulled on our citizenry. Determining the feasibility of this and other designs in the face of the challenge of toxic contamination is not rocket science and would not be that expensive. I'm guessing 40 to 100 soil samples would give a good preliminary characterization. Because we know from this and other rail yards around the US what to look for, the samples would be analyzed for a comparatively short list of contaminants. I'd guess it might cost $500 to $1500 per sample analyzed. So, lets just say 60 samples at $1000 each. Then add in $40,000 for writing a report and study management. To really have a basis for discussion we are looking at very roughly $100,000. DOTD now has let over $50 million in contracts, and spent untold amount in-house, but refuses to spend a penny to actually get the information needed.

    It is my best guess (and I am a retired environmental professional engineer) that we will finally discover that all this plan to excavate the waste is infeasible. That, by the way, was DEQ's conclusion based on very limited data. They found removal to be "economically and environmentally infeasible." Removal would endanger the neighboring and downtown public, the workers, and both our surface water and ground water. No doubt it could be removed, but at a very high cost and risk. The reasonable approach is called in-situ remediation, but that is probably incompatible with putting an interstate highway, bridges, or underpasses at the site.

    So,Robert,I am very frustrated that we are left discussing these option without the needed data. I can only guess that DOTD does not want the answer. They are burning through "free" federal dollars on the project and don't want anything to risk stopping their cash flow.

    1. You might like to read my post at

  3. DOTD will not spend the money to investigate the soil samples. That's not their job until a design is approved... And A design will be approved. That is for sure as it's built into the process. I'm skeptical too, however I refuse to allow my concerns dictate my decision. I see no reason why we can not support a cut & cover option ONLY stipulating that soil sampling and environmental safeguards be built into the process at every step. And in lieu of this a Teche Ridge option is preferred as we should not have to choose between the safety of our aquifer and the redevelopment of the entire area that will occur as a added benefit of the project.

    I just don't agree that we must prove anything before we know what design(s) will be studied. Once we have a design they will have to conduct these studies and before construction would ever start all environmental remediation would need to occur along with insuring the design poses no threat to our aquifer. I do NOT support a raised solution at all though at some points along the length of the project this may be best for the design... Just not near downtown or areas of the aquifer where pollution and construction creates an imminent threat.

    SO... Why not be for a cut & cover and against any other solution? You honestly think leaving what we have now is best?

    It will take years before construction would begin and during this time the on site bioremediation can start to minimize removal of contaminated soil. But this process has to occur after a design is chosen, not before. Getting the federal government involved is necessary to not only finance removal & intensive bioremediation of polluted areas but ALSO to sue the companies responsible for this environmental devestation... Which could otherwise take citizens or our city 10-20 years and cost millions of dollars. Meanwhile the risk remains, the neighborhoods torn by the thruway remain, the lack of tax base and jobs languishes along with no stimulus that will create jobs and increase property values.

    I challenge you to research cut & cover designs and similar park deck solutions around the country. The Sierra Club supports a cut & cover in Austin, TX. When done well they work great.

    Let's unite around a responsible & comprehensive cut & cover development along with neighborhood revitalization that prioritizes the safety of our aquifer OR the Teche Ridge option. Let the process move forward. After the design is completed the environmental studies come next. Then we will be much better able to assess the project's viability given the environmental concerns.

  4. There are many examples out there. Expensive? Yes. But they also generate revenue and solve many other problems, especially with our unique set of circumstances. Here is some good info.

  5. I'm a supporter of the Depressed/Covered Mainline option exactly because it could encourage more economic development and renewal of the downtown and surrounding neighborhoods within Lafayette. However, unlike Robert (or Michael), I'm not so convinced that the elevated option couldn't be made more adaptable to such development. The modifications of eliminating the two standalone interchanges downtown in favor of a collection system using the existing Evangeline Thruway, retaining a fully elevated structure through downtown, and restoring more connectivity underneath the elevated structure, could do a lot to complement the neighborhood redevelopment plan put forth by the ECI. Also, the recent flooding may be the pivot for LADOTD and FHWA to discourage the Partially Depressed/Covered option and go fully elevated for reasons of maintaining the Connector as a hurricane evacuation route above ground level.

    It should be also noted that the proposed PD/C option of the ECI that has been endorsed by almost all LCG officials would center the freeway roughly on Chestnut Street midway between the railroad and the southbound Evangeline Thruway roadway; allowing the overcrossing berms and streets to slope back to ground level before reaching the railroad. That would not only eliminate the visual impact of a wall at the rail line; but would also remove the need for overpasses of the railroad, since all crossing would be at-grade. The Elevated option would probably be more imposing visually, but, with the elimination of the interchanges, it becomes a much less divisive and more development-friendly option. I'd still prefer that as a second option to the PD/C, rather than a bypass.

  6. And, once again, I should note that explicit soil sampling will take place along the SP railyard property in advance of a full remediation and cleanup once final design begins before construction is implemented. That is FEDERAL and STATE LAW.