Assess VMT Reduction due to the Maryland Historic Tax Credit Program

Focus Area

Historic Preservation/Cultural Resources


Community & Cultural Concerns




Under $99k


Under 1 year

Research Idea Scope

Northeast-Midwest Institute (NEMW) would partner with the National Trust for Historic Preservation and the Sierra Club to carry out this study. NEMW, in a recent study funded by the Abell Foundation in Baltimore, assessed the environmental and economic impacts of the Maryland Historic Tax Credit program (see:  Although not part of the original scope of work, NEMW made an “order of magnitude” estimate of reduced vehicle miles travelled (VMT) attributable to tax credit projects in comparison to suburban sprawl development patterns.  The conclusion was that Maryland tax credit projects are generally characterized by precisely the factors that, according to national research, are also correlated with VMT reduction (in rank order): density, mixing uses, proximity to jobs, access to transit, and connectivity of the streets and sidewalks.  National research also indicates that development meeting those characteristics, generally referred to as “compact development,” reduces VMTs by 20 to 40 percent relative to sprawl development.  The Maryland data gives strong evidence that the tax credit projects are in the 30 to 40 percent (or the high part) of the range for VMT reduction attributable to compact development. It is proposed that this study be expanded and brought up to the standard of a professional, peer-reviewed, and publishable piece of research.  There are two reasons for the follow-up: 1. This methodology – predicting VMT reduction by virtue of the correlative characteristics of redevelopment projects – is not well established in the literature.   However, there is certainly a demand for precisely this information as policy makers increasingly need to understand the impact of development incentives on climate change. 2. Because of funding limitations and time constraints the Abell project involved a number of assumptions that need to be validated and left some important data gaps which should be filled. The following is a proposal for improving the VMT reduction projections in the Abell study: 1. FORM A PEER REVIEW GROUP – review the methodology and assumptions with the peer review group.  Refine the methodology and data needs, as appropriate. 2. ADD MAIN STREETS.  The project has thus far addressed only the historic tax credit program.  Adding Main Streets (the preservation of historic downtown and neighborhood commercial centers) would give the findings broader application and would accurately reflect the smart growth/climate benefits of the two most significant preservation programs.  3. IMPROVE AND EXPAND DATA.  NEMW had access to data that enabled quantitative ranking of three of the five factors that are linked to VMT reduction.  The three that were counted were: population density, mixing uses, and proximity to jobs.  The two factors that we were unable to quantify were access to transit, and connectivity.  These should be added to the data.  Other data points should be improved.  For example, 2000 census data was used to indicate population and job density, and an update would improve accuracy.  Additionally, several new data sources should be tapped: a developer survey should be carried out to determine the density of the projects; and Baltimore Metropolitan Council survey data should be accessed in order to refine VMT per household data. 4. REVISE ANALYSIS AND CONCLUSIONS

Urgency and Payoff

Policy-makers need to understand the VMT and GHG implications of development incentives.  The Rehabilitation (historic) Tax Credit has been generally regarded as one of the strongest smart growth development incentives, and is therefore an excellent test case for an analysis that attempts to quantify VMT and GHG reduction relative to sprawling development patterns.  The proposed methodology is a streamlined approach in that it does not involve complex modeling or surveying.  Rather, it looks at the attributes of the redevelopment projects and their immediate environs; correlates those attributes with VMT characteristics by virtue of previous research; and projects VMT and GHG reduction according to those correlative relationships. It is important to “get this right,” both because the methodology is not well established and because of the important policy implications of the findings.

Suggested By

Evans Paull, Northeast-Midwest Institute