Introduction

The Athena Pavement LCA is a life cycle based environmental assessment tool that lets highway designers, product specifiers and policy analysts compare the relative environmental effects or trade-offs across alternative highway design solutions at the conceptual design stage. Some of the Pavement LCA’s specific features include:

• the ability to model the highway's roadbed design over the service life of a highway;
• the ability to model construction, maintenance and rehabilitation life cycle effects based on user defined schedules and service life for the highway;
• a context sensitive help facility in place of a users’ manual; and,
• the capability to model Canadian regional locations.

Pavement LCA results are presented in various ways and levels of detail to meet the needs of different types of users. A researcher wanting detail can see the results by specific energy forms or waste substances, by life cycle stage and by assembly type. An engineer may only be interested in tabular or graphical displays of summary measures or characterisations by roadway assembly and for the total design. The Pavement LCA also allows the user to make direct comparisons among alternative designs on an absolute basis, on a per kilometer basis or on a relative basis where one design is selected as the baseline project.

Using Pavement LCA, engineers and others can easily assess and compare the environmental implications of radway designs–both for newroads and major rehabilitations.

Pavement LCA puts the environment on equal footing with other more traditional design criteria at the conceptual stage of a project. It incorporates ATHENA’s own widely–acclaimed building (expanded on for roadway materials) material life cycle inventory databases as well as those contained in the US LCI database (www.nrel.gov/lci).

Pavement LCA takes into account the environmental impacts of:

• Material manufacturing, including resource extraction and recycled content
• Related transportation
• On-site construction
• Regional variation in energy use, transportation and other factors
• Maintenance, repair and rehabilitation effects

 

Web App

Click here if you want to use the Pavement LCA web app instead of the desktop application.

 

A Special Note about the "End of Life" (Demolition) Module

The "End of Life" is inactive at the moment, because in reality, the highway is never demolished and disposed of.  For now, the module remains as a placeholder for future development of a protocol to display, for example, the effects of disposing materials that are replaced during the maintenance and rehabilitation phases (this is currently included in those phases), or the operation phase (traffic use, lighting, etc.).

 

Complex Results in a User-friendly Format

Although LCA is a complex process, Pavement LCA has been designed for ease of use.

The first step is to enter required information such as geographic location (the system allows users to select from specific Canadian regions), expected service life.

Pre–set dialog boxes prompt users to describe the different roadways by requesting the geometry of all lanes, shoulders, and material layers, that together form a conceptual highway design. Pavement LCA then instantly provides cradle–to–grave implications in terms of:

 

Simplified Tracking

As design data is entered for each assembly, the software builds a “tree” so that each individual assembly can be identified and viewed easily. The tree can also display, in value or percentage terms, the impact of each assembly in terms of a selected measure such as global warming potential. This allows users to track affects of each assembly as it’s added, or to quickly pinpoint which one is causing a particular environmental effect.

 

Detailed LCA Results

Results from an individual design can be seen in summary tables and graphs by life cycle stage. Detailed tables and graphs show individual energy use by type or form of energy and emissions by individual substance for the life cycle stage breakouts.  Possible future development could include summarizing results by design groups when infrastructure or access roads for example are added. Presently, there is only one desugn type, the roadway, so this table is unnecessary.

 

Make Flexible Comparison of Alternate Roadway Designs

Accommodating up to five comparisons at once, Pavement LCA allows users to change the design, substitute materials, and make side–by–side comparisons for any one or all of the environmental impact indicators. Or compare the new roadway design to one you did last year. You can also compare similar projects with different roadway surface areas on a unit roadway surface area basis. Pavement LCA can perform as many as five project comparisons at a time.