Environmental impacts of a highly congested section of the Pan-American highway in Peru using life cycle assessment

Purpose: Road construction and transportation generate significant environmental impacts. Hence, it is increasingly important to understand the environmental burdens produced throughout the different stages of road development: construction, maintenance, traffic, and end-of-life. In this study, life cycle assessment (LCA) was used as an environmental management methodology to determine the impacts associated with a 22.4 km stretch of the South Pan-American (PS) highway in the province of Lima, Peru, one of the main access routes for traffic and goods entering Lima, located in a hyper-arid area parallel to the Pacific Ocean. Methods: Life cycle modeling included the site-specific estimation of particulate matter emissions due to tire abrasion, brake lining, and road surface dust. In addition, different modeling options for combustion emissions for vehicles were considered. For this, sensitivity and uncertainty analysis were undertaken considering different emission standards and current vehicle fleet characteristics. The impact assessment stage included the calculation of climate change emissions, as well as air quality and abiotic depletion impact categories. Results and discussion: Results demonstrate that environmental impacts are mainly attributable to traffic, representing in all impact categories assessed over 97% of burdens. The sensitivity analysis suggests that the use of secondary data from commonly used life cycle databases is a good proxy for the estimation of global warming potential impacts in the transport sector. However, for air quality categories, important variability was detected based on modeling assumptions. Conclusions: This study intends to serve as a reference for the life cycle modeling of controlled access highways in developing countries, particularly in hyper-arid or desert areas.