Sustainable transport planning: Estimating the ecological footprint of vehicle travel in future years

An important indicator of sustainable land use, the ecological footprint measure has proved unsuitable for many planning applications because of the limited availability of impact data at the local level of cities and counties and because of an inability to estimate the ecological footprint of future development scenarios. In light of these limitations, this paper presents a methodology for measuring the ecological footprint of a county-level transportation network in current and future time periods. With the aid of vehicle travel behavior and fleet characteristics obtained from a number of state and federal agencies, we estimate the quantity of land required for constructing county highways and remediating annual greenhouse gas emissions through forest carbon sequestration in the years 2001, 2011, and 2021. The results of our study, which focuses on Houghton County, Michigan, indicate that, despite a projected increase in average vehicle fuel efficiency, the ecological footprint of transportation will increase in future years because of projected increases in total annual vehicle kilometers of travel along the network. On the basis of these results, we argue that the ecological footprint is a viable technique for transportation and land-use planning applications.