Sustainability is a complex and systemic challenge: in dealing with sustainability, as with all other new concepts, it is preferable to be explicit in order to align on common interpretations and levels of ambition . This blog is about sustainable mobility: but what is that? Without opening the background boxes of complexity and sustainability (which we can talk about later), we will draw a few lines here jumping directly to the more specific instance of sustainable mobility.
Probably one of the most referenced attempt at defining sustainable mobility comes from Professor David Banister, who offers this simple comparative table between the ‘conventional’ approach (to transport planning) versus the new paradigm of ‘sustainable mobility’ .
Various other institutions have tried to define sustainable transport deconstructing from the usual three dimensions of sustainability, with mixed and confusing success as they typically fail to account for the interconnections and synergies between the dimensions, while at the same time underestimating potential limits or thresholds within the dimensions that could prove irreversible. We will ignore those. Finally, away from the conceptual and more into the operational side, Holger Dalkman proposed the Avoid-Shift-Improve strategic framework to address the sustainable transport challenge, which we will reuse here ‘as is’ (as have done many authors, including Banister and the United Nations).
Thus, based on the above, drawing from complexity theory  as well as a (yet undefined here) strong definition of sustainability based on the Brundtland report, the Natural Step precautionary principles of sustainability and the Stockholm Resilience Centre Planetary Boundaries [5–7], we propose the following normative principles of sustainable mobility. For a country, region, institution or agency to plan successfully for sustainable mobility, it shall:
- Address sustainable development as a systemic and complex challenge, which requires not only consideration for each dimension of sustainability, but also how they are interconnected , noting that complex problems are best addressed with a mix of multiple (soft and hard) methodologies ;
- Take into account long term impacts and feedback cycles, such as environmental and social consequences associated with transport systems, and thus internalize and prioritize long term goals with the more conventional short term ;
- Expand the environmental dimension of sustainability beyond CO2 emissions and prioritize other relevant planetary boundaries and thresholds, such as biodiversity loss and chemicals dispersion , operating within which is a necessary condition for sustaining human life (and thus its societies and economics) given our current state of technology ;
- Refine the social dimension of sustainability by including considerations for fundamental human needs and separating those from wants and the means to meet those needs, which enables the reframing of entrenched opinions (such as “I need a car”) and allow for more creative and acceptable solutions by stakeholders ;
- Create and integrate into decision-making a virtual ‘future generations’ stakeholder (our children’s children) to set the benchmark from a sustainability perspective to compare to;
- Define a desired state, a vision of sustainable mobility, based on precautionary principles of sustainability (like the Natural Step) in order to strategically backcast and keep momentum in defining and implementing the steps required for sustainable development, with the assumption that ‘optimal solutions’ will become self-evident and less contentious when a clear desired state is set;
- Generally internalise the full environmental and societal externalities in appraisal and charge the true costs of transport modes (for example for using a car during peak hours)
- Plan for and implement broad schemes and measures that go beyond traditional infrastructure projects, following ‘Avoid-Shift-Improve’ strategies, where,
- Avoid: integrating transport with land-use planning and managing transport demand in order to reduce the need for transportation;
- Shift: accommodating growing transport demand by making less resource- and energy- intensive modes – such as walking, cycling, rail and other forms of public transport – more attractive and by promoting multimodal transport;
- Improve: promoting systems and technologies that are alternative to fossil fuel based transportation and making current modes more efficient;
- Consider and plan for possible unintended or rebound effects from measures, for example the Downs-Thomson paradox and the Lewis–Mogridge position whereas increasing road capacity may in practice induce more congestion;
- Build legitimacy: renew focus on positive discourses, structural stories and perceived benefits such as increased accessibility, livability, attractiveness, health, future-proofing, designing cities and spaces for people, and generally encouraging quality of life through more sustainable behaviours ;
- Allow for prototyping: renew focus on the bottom line of transportation motivations (cost-safety-speed-comfort-identity); people have a legitimate need for accessibility, and thus in most cases mobility, and choice of mode will depend on how well basic expectations of speed and comfort are met and balanced with sanity criteria of cost and safety, as well as addressing underlying needs of identity;
- Create broad and engaging coalitions: involve broader but also more focused groups of stakeholders in the transport governance processes from the start, including planners, businesses and civil society, as well as getting early buy-in from politicians 
 S. L. Jeppesen, “Sustainable Transport Planning – A Multi-Methodology Approach to Decision Making,” DTU Transport, 2009.
 D. Banister, “The sustainable mobility paradigm,” Transport Policy, vol. 15, no. 2, pp. 73–80, Mar. 2008.
 H. Dalkmann and C. Brannigan, “Transport and Climate Change. Module 5e. Sustainable Transport: A Sourcebook for Policy-makers in Developing Cities,” Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ), 2007.
 S. Leleur, Complex strategic choices. 2012.
 G. H. Brundtland, “Our common future,” United Nations, 1987.
 J. Holmberg and K.-H. Robèrt, “Backcasting from non-overlapping sustainability principles–a framework for strategic planning,” International Journal of Sustainable Development and World Ecology, pp. 291–308, 2000.
 J. Rockström and W. Steffen, “Planetary boundaries: exploring the safe operating space for humanity,” Ecology and Society, vol. 14, no. 2, pp. 1–23, 2009.
 R. B. Gibson, “Beyond The Pillars: Sustainability Assessment as a Framework for Effective Integration of Social, Economic and Ecological Considerations in Significant Decision-Making,” Journal of Environmental Assessment Policy and Management, vol. 8, no. 3, pp. 259–280, 2006.
 A. Bergek, S. Jacobsson, and B. a. Sandén, “‘Legitimation’ and ‘development of positive externalities’: two key processes in the formation phase of technological innovation systems,” Technology Analysis & Strategic Management, vol. 20, no. 5, pp. 575–592, Sep. 2008.