The “price” of saved time, the illusion of saved fuel: Life-Cycle Assessment of a major highway expansion

The road transport sector is a major responsible for pollutant greenhouse emissions. Airborne and other types of environmental impacts involve much more than just the most addressed driving activity and its combustion residues. Building upon a previous work rooted in systems thinking and emergy accounting, Life-Cycle Assessment is applied to transport studies in order to evaluate the environmental performances of a civil infrastructure in Italy before and after major expansion and deviation works: altogether, these methods are used as comprehensive tools to measure sustainability, while including resource consumption and requirements, direct and indirect environmental impacts, and their effects on human health, all depicted by a wide selection of 30 standard indicators. The expansion project, completed in recent years, is compared with the no-build option as well as with the results from the previous cost-benefit and emergy-based systemic assessments, thus shedding novel light on road construction and appraisal compared to purely economic and purely ecological tools only. Life-Cycle Impact Assessment results are expressed in terms of impact indicators per full highway section, but results per road length unit (km), and per transport service unit (p-km and t-km) can be derived. Unlike the claims by managing authority and policy-makers, an overall worsening is found in all of the adopted environmental indicators, although differences exist among them (from +47% up to +244%, with most indicators doubling or even tripling after the renovation works). Expected on-road fuel savings, where applicable, just mitigate an overall negative situation: such savings are overcome by the effects of the fuels indirectly required to obtain them, and by the overall impacts following the expansion, albeit normalised through relevant amortisation. The only stable saving, i.e. travel time, stays structurally out of a Life-Cycle Assessment, whose clear results can serve as a basis for possibly long-sighted design, planning, and decision-making in an era of urgently needed environmental actions.