Anticipating transitions beyond the current mobility regimes: How acceptability matters

• Identification of shared and automated as core components of more sustainable transportation systems.
• Four consistent scenarios of future transportation systems that represent different degrees of innovation.
• Scenario evaluation by ten criteria of user-acceptability.
• Outline of an innovative implementation setting within the current transportation system.

Today's car-based transportation systems require a transition toward sustainability. This is particularly the case in suburban areas, where the costs for introducing a new transportation system are high due to the low population density. At the same time the negative externalities of the current mobility regime – such as health costs and congestions – are increasing rapidly. Based on expert interviews with car manufacturers, transportation authorities, environmental groups, and scientists we identify two visionary characteristics of future, more sustainable transportation systems: automated driving and sharing. Using these two characteristics, we apply the scenario-axes technique to develop four mobility scenarios for a suburban context that range from business-as-usual to a radical and more sustainable one. In an evaluation with ten criteria that measure a scenario's performance from a user perspective, the radical scenario performs worst since it does not meet current individualistic user requirements. Our findings suggest that lock-ins of users’ expectations act as barriers for the diffusion of novel transportation systems. These barriers cannot be overcome by technological innovations and regulation alone. Hence, we call for innovative arenas, wherein technology and user acceptability could co-evolve.