Sustainability and Highways
The goal of INVEST is to make highways more sustainable than common practice dictates today.
At first glance, many practitioners consider the term "sustainable highway" an oxymoron because of the significant material requirements and the impacts to the human and natural environments due to highway development and vehicles use of the system. However, when considering the triple bottom line principles, one must also consider the social and economic benefits that our highways provide, including access, mobility, and the economic benefits of moving people and goods. In that context, highways can be seen as a more sustainable part of our infrastructure - and certainly a necessary infrastructure of our society.
The purpose of INVEST is not necessarily to make highways sustainable, but rather to make them more sustainable than common practice dictates today. Moving the bar toward sustainability will not only reduce the impacts on our human and natural environment, but will increase the benefits to the entire triple bottom line.
This section discusses definitions of sustainability, sustainable highways, and why and how to measure sustainability.