Athena Pavement LCA is a free LCA-based software package that measures environmental impact of Canadian and US roadway designs.

This software tool provides environmental LCA results for Canadian and select US regional materials manufacturing, roadway construction and maintenance life cycle stages. It allows custom roadway design, or users can draw from a library of over 150 existing roadway designs. The software includes a large equipment and materials database and the flexibility to specify unique pavement systems – sub-base and base granular materials as well as hot and warm mix asphalt and a host of user-specified concrete mix designs. Users can also input use-phase operating energy and apply built-in pavement vehicle interaction algorithms, if desired, to be included in the final LCA results. The software allows for quick and easy comparison of multiple design options over a range of expected roadway lifespans.

This software was made possible by support from the Cement Association of Canada and Athena Institute members. The earlier software prototype and beta version was developed in association with transportation engineers at Morrison Hershfield, and was funded by Environment Canada.

The Athena Institute is interested in hearing from potential partners in the further development of this tool for other N. American locations and customized needs.

How it works

The Athena Pavement LCA tool is an LCA-based software package that makes life cycle assessment data easily accessible to roadway decision-makers. Built using the same methodology as the well-established Impact Estimator for Buildings, it provides a life cycle inventory profile for a given three-dimensional roadway design. The inventory results comprise the flows from and to nature: energy and raw material flows, plus emissions to air, water and land. The software reports life cycle impact assessment results by activity stage and enables easy comparison of different design options. The purpose of the software is to enable decision-makers to bring environmental effects to bear.

Inputs

Users quickly describe roadway construction and rehabilitation parameters through a few easy input screens (base, sub-base and surface pavement), and can then view results a variety of ways. In the background lie several large databases on materials, energy, equipment and transportation, sourced from the Athena Institute, the US LCI Database, and others. Material data represent national or industry averages for the extraction, processing and manufacturing of each material. Regional energy grids and transportation distances are applied to the average data to arrive at regional data profiles. Roadway lifespan is variable and dictates rehabilitation events such as scheduled resurfacing. Results are reported on a gross roadway surface area basis.

Results

The Pavement LCA tool reports footprint data for the following environmental impact measures consistent with the US EPA TRACI methodology: global warming potential, acidification potential, human health respiratory effects potential, ozone depletion potential, smog potential, and eutrophication potential.

The software also reports fossil fuel consumption and presents a Bill of Materials report that sums up the totals of each material in the user’s roadway design. Operating energy can be included in the LCA if the user inputs an estimate for annual operating energy consumption by fuel type. Similarly, PVI effects can be estimated by entering roadway roughness and deflection modulus values between major roadway rehabilitations. The software will calculate total energy, including pre-combustion energy (the energy used to extract, refine and deliver energy) and the related emissions to air, water and land over the life cycle of the roadway, and can subsequently compare the life cycle operating and embodied energy and other environmental effects of various design options, allowing the user to better understand trade-offs. The software takes into account the environmental impacts of the following life cycle stages, including related transportation: material manufacturing, including resource extraction and recycled content; on-site construction; use phase (with or without PVI effects) and maintenance and replacement effects. Demolition and disposal are excluded, as highways typically have very long service lives.

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