ABSTRACT
At present, pavement design and rehabilitation decisions are based solely off economic factors and in-place policies at the majority of state and national transportation agencies. Essentially, these design methods aim to meet a certain performance standard at the lowest possible owner costs, whereas the environmental and user perspectives are usually ignored. To overcome these limitations of traditional design approaches, Life Cycle Assessment (LCA) is increasingly being employed to guide infrastructure design and planning in the recent years. LCA allows quantification of the cradle-to-grave/cradle economic and environmental impacts of construction, maintenance, operation and end-of-life phases of an infrastructure system. While the use of LCA has been extended to activities such as pavement design and construction, it has rarely been applied in evaluating pavement rehabilitation strategies. This study coupled traditional LCA with dynamic pavement roughness predictions (in form of International Roughness Index) obtained from the AASHTO’s PavementME system and the vehicle fuel consumption and emission factors calculated through the calibrated Highway Design Manual-4 (HDM4) to provide dynamic life cycle environmental and economic impact assessments of various pavement designs. Recommendations on the optimum pavement roughness levels at which asphalt overlay treatment is applied have been developed to minimize environmental and economic impacts. The framework was applied to a 27 km-long stretch of interstate highway (I-95) in New Hampshire, results of which are discussed in the paper.
