Bypasses, which redirect through traffic around a community’s downtown area, could have substantial impacts. Identifying these impacts and attributing these impacts solely to the presence of a bypass has posed a challenge to decisionmakers and researchers. The economic impacts have the potential to be longterm and farreaching. Because impacts take place over a long period of time, and because these impacts cannot be easily isolated due to economic externalities (such as recessions), researchers have found it difficult to establish a standard estimation framework for determining bypass impacts. Recent studies (Mills and Fricker 2009, for example) have used econometric and other quantitative methods to determine the extent of these economic impacts. This study will use longitudinal mixedeffects models to study the economic impacts of eight bypasses located in north central Indiana.