Friday, April 2, 2010

Our Fractured Roads and Pollution -- When is a Network Robust?

As one drives over the roads in Amherst and surrounding towns in western Massachusetts, one can't fail to painfully feel the bumps and potholes, and hope that one reaches one's destination without getting whiplash and one's car is still functional. It is embarrassing that in the "richest" country in the world that we do not maintain our infrastructure appropriately. Not only does this lack of maintenance result in costly repairs on the backs of citizens, but it also results in increased pollution emissions.

In a study, just published and entitled, Environmental Impact Assessment of Transportation Networks with Degradable Links in an Era of Climate Change that I wrote with Drs. Qiang Qiang and Ladimer Nagurney, in the International Journal of Sustainable Transportation 4 (2010) pp 154-171, we were able to capture the effects of transportation network infrastructure degradation on the pollution emitted in the form of carbon emissions. In addition, we constructed link importance indicators that enable the ranking of links (under either user-optimizing (U-O) selfish behavior or system-optimizing (S-O) unselfish behavior) in terms of the impacts of their degradation and even their ultimate destruction. As is evident from recent disasters such as earthquakes and floods, such quantitative measures are more than timely and relevant.

With this paper, we hope to promote a new research agenda into the determination of quantitative measures associated with transportation networks, environmental vulnerability and robustness analysis, and climate change. Moreover, planners and policy makers need to be able to rigorously assess which links (and nodes) in transportation networks from congested urban ones to freight ones should be carefully maintained and invested in. Otherwise, we will be living and trying to be mobile in a Fractured Fairy Tale.