The economic impacts of highway widening projects

Abstract

Highway widening is one alternative for increasing capacity on a particular section of roadway. Capacity is the maximum hourly rate at which vehicles can reasonably be expected to traverse a uniform section of a roadway during a given time under prevailing roadway, traffic, and control conditions. Added capacity has economic, environmental, and social impact tradeoffs that must be considered. Economic tradeoffs of land value impacts were considered for this research study. Land scarcity, as related to value, was analyzed with respect to highway widening improvements on abutting land use. Previous literature included several modelling techniques used for measuring economic impacts of highway improvements. The before-and-after study approach was selected for analyzing land values, rather than parallel-area or control-area study approaches. This study involved a before-and-after economic analysis, where the before period d represented economic make-up of land parcels without Improvements, while the after period represented market value on land parcels once construction was completed. A design matrix was developed from data available for two highway types, multilane highway and freeway, on pre-selected sites. Location selection was based on prior knowledge and availability of land value data. Study variables included four design characteristics and four property types. These variables were used to determine whether increases in land value occurred on adjacent properties as a result of widening. A paired data statistical analysis was performed for both facility types. Results of the statistical analysis indicated that property values generally decreased for both facilities. Impacts on abutting property for each location reflected minimal changes in value. Therefore, the results do not suggest an increase in property values because of highway widening. The most important recommendation from this research study includes a combination of two factors.- 1) further research needed to look at areas outside of the construction zone and 2) consideration for lengthening the after study period. The parallel-area or control-area study approach is recommended for further study of economic impacts on land values. In addition, more data for the after construction period, preferably five to ten years, could be applied to better estimate effects.