Where are we heading, and where do we want to go?

QC 20250514

Abstract

This thesis is written at a time when a considerable gap exists between the current trajectory of the transport system and developments in line with societal goals, such as those set to reduce greenhouse gas emissions. Responding to the challenge, the thesis explores what futures aligned with societal goals can entail. Transport system scenarios fulfilling climate goals are developed and analysed, examining the potential of electrification, biofuels,and vehicle efficiency. The thesis also pays special attention to New MobilityServices (NMS), which enables mobility through vehicle sharing andridesharing. In addition to developing scenarios where NMS are included, are view explores other studies in which target-fulfilling scenarios have been developed, to understand possible future roles of the services. The thesis also investigates potential contributions from mobility and accessibility services to reduce transport volumes, facilitating a modal shift from car use to alternative transport modes, and enhancing the environmental performance of cars when in use. Potential tensions associated with NMS are also explored, which can be barriers to successful implementation at scale.

The thesis contributes to the understanding of what future transport systems achieving climate goals could entail. The results show that a combination of technological advancements and behavioural changes will be necessary. Significant contributions to emissions reductions are expected from, for example, electrification, biofuels, and improvements in vehicle energy efficiency. Despite this, there is still a need to reduce transport volumes from cars, air travel, and freight via road networks to an extent that represents a major break in trends. This is partly due to the insufficient maturity of technological alternatives and the long turnover time of the passenger car fleet, which limits the progress of electrification. It is also due to the fact that biobased raw materials for fuel production are limited resources from both territorial and global perspectives. Moreover, even vehicles with low direct emissions result in significant emissions from lifecycle stages such as the production of vehicles and fuels. It is demonstrated that large vehicle fleets may be challenging to reconcile with climate ambitions concretised through the European emissions trading system.

Another contribution of this thesis is an improved understanding of potential futures for NMS. A potential role of NMS in achieving societal targets such as greenhouse gas emissions reductions is concluded. In the developed scenarios, car-sharing plays an important role in ensuring car access when the number of cars decreases. Mechanisms are also identified through which several services can contribute to avoiding transport, shifting from car travel, and improving environmental performance when cars are used. However, negatively contributing mechanisms are also identified, and a challenge arises from the fact that the mechanisms are intertwined in complex relationships and embedded in contexts that have implications for the final impact. In addition, 168 identified tensions presented within a set of ten themes demonstrate challenges to the feasibility of future sustainable transport systems where NMS plays a significant role, which needs to be navigated. The tensions involve public entities, private organisations as well as citizens/users. It is concluded that there is a need to connect individual mechanisms and tensions to cumulative system level impacts and to maintain a systems perspective when investigating the effects of the services.

urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-363333