Illinois promotes sustainable highway projects with I-LAST

I-LAST is also a great way for the road construction  - and asphalt industry in particular - to toot its own horn, since asphalt is the number one recycled material and asphalt contractors are overachievers when it comes to sustainability.

"I-LAST is a new, one of a kind document that allows the transportation industry to highlight it’s dedication to sustainability," says Tatro. This document will hopefully help change the perception that the transportation industry is old machines, when in fact, they are ahead of the curve and utilizing recycled asphalt."

Additionally, the IRTBA Green Council released its Construction Practices Addendum to the I-LAST manual. Both parts establish criteria for identifying and implementing practical and measurable green design and construction techniques and products for transportation projects.

The Construction Practices Addendum encourages companies and agencies to promote innovations, and experiment or use ideas and concepts that might not be included in the current specifications but should not be entirely ruled out, says Tatro.

"This is simply a tool for considering unique opportunities," says Tatro. "The Innovations section is meant to foster creativity and continued growth within the green transportation industry. This is a place to highlight experimental options and earn points for creativity."

Project evaluation

I-LAST includes a point system for evaluating the sustainable measures included in a highway project.

In the materials category, for example, if a contractor recycles on-site during a project, instead of hauling material off and back on again, the project is awarded points. In the design category, if a project minimizes earthwork by aligning grades as closely as possible, the project is awarded points. Several aspects of the design and construction processes and materials are considered.

The purpose of the scoring system is to give different points depending on the significance of the item, explains Fortmann. "Standard practice items were 1 point with more significant items 2 and 3 points," he says.

Due to the varying nature of highway projects and the range of items in I-LAST, there will often be a large number of points that are not applicable on an individual project. Therefore comparing the absolute score of different projects would not accurately indicate the level of sustainability for those projects.

Projects can be evaluated based on the inclusion of the practices that were applicable to the project. The evaluation can consist of two steps:

1.  At the beginning of the project, the project team can determine which elements apply to the project. Those items that are applicable can be noted and considered in the development of the project.

For instance, on a highly urban project there may be no wetlands in the project corridor, and the wetland items would not apply to that project.

2. At the end of the project, the team can determine which of the applicable items were included in the project plans. This evaluation can then be included in the project’s file.

The final score is based on a percentage of the points available. Of the available 153 items, there is a maximum score of 233 points.

The scoring is intended to be relatively simple and require minimal time and effort. "We wanted to focus on sustainable results, not paperwork," says Knuth. "This system is designed so that a project manager can score a project in about an hour."

Projects & their scores

Several major Illinois road building projects have already been scored. Following is a brief description of three projects and the components that helped with their sustainability ratings.

I-55 at Arsenal Road, Will County

The I-55 at Arsenal Road Interchange Project, a $60 million project, is currently underway. The project includes interchange reconstruction and relocation traffic maintenance during construction, frontage road construction and interchange embankment placement, traffic maintenance during construction, roadway connections and existing interchange demolition, and widening of the northern portion of the Arsenal frontage road.

Design Score: The project scored 87 of 165 possible points.

Some components of the overall score: