The aim of the project was to establish the whole-of-life environmental performance of passenger and freight movement that uses roads and rail. The performance indicators selected were life cycle energy consumption, life cycle stormwater contamination, and life cycle GHG emissions. This study was based on process assessment and considered material use, transport requirements, on-site machinery use, and fuel use. The impacts of traffic delays and rolling resistance were not considered. The study was undertaken in New Zealand between October 2009 and March 2011 using data for the year beginning July 2007 and ending June 2008.
The results suggest that the environmental impact of pavements can be altered by earthworks (especially in hilly terrains), choice of construction system, and wearing-course construction. Rail emissions can be influenced by the source of the steel rails used. For passenger transport, fuel use is the dominant factor; for freight transport, infrastructure, vehicles and fuel are equally important. However, the use of rail for passenger and freight transport leads to far greater reductions in energy and carbon emissions when compared against all modes of road transport.
The results derived using New Zealand data are significantly different from those using European data. It is therefore essential to use local data in evaluations of transport policies and actions.