Future transportation: Lifetime considerations and framework for sustainability assessment

Modern society cannot exist without mobility. It is now essential to maintain access to everyday necessities, as well as being a vital part of most economies. However, our current transportation system is placing unsustainable demands on finite resources of fossil fuels, minerals and materials; change is therefore essential. Identifying rational choices is difficult because a future transport option must not only abate these demands over the entire lifetime, but do so at an affordable cost whilst maintaining acceptable levels of utility. This paper offers a framework to evaluate powertrains for whole life criteria, in order to help validate current and future developments. It supports integrated comparisons of both fuel and vehicle technology combinations for cost, energy and greenhouse gas emissions throughout a vehicles lifetime. Case studies illustrate the use of this framework. All powertrains were found to require considerable amounts of energy and emit some emissions over their whole lifetime. Significant benefits over incumbent vehicles were found to be potentially attainable through the use of alternative powertrains. However, the majority of these benefits were currently found to increase user costs, worsen the vehicle production impacts and be heavily reliant on the source of the vehicles in-use energy.