The achievement of the ambitious goals set by the European Union for the reduction of greenhouse gas emissions expected by 2050 and the improvement of air quality in urban centres can only be achieved with a drastic change in people's mobility habits and in freight transport. This requires also an adequate realignment of planning with environmental objectives, promoting innovative sustainable mobility projects. Transport planning is firmly inserted in a neoclassical economic framework, which presupposes perfect rationality in all decisions. However, this intellectual framework has been questioned by an alternative approach. What is your opinion on this?

These goals are ambitious according to the current transportation system, the current state of mind, the current practices. However, they may be realistic according to the challenges of global change (and the drastic changes in terms of mobility habits).

I agree with the fact that transport planning (including mobility plans) tend to focus on the individuals (neoclassic or not; engineer but also psychology), on attitudes, behaviours, choices. They suppose that individuals are rational (and that individuals use the transport infrastructures as we plan them) and that if they have the required information, they would change.

But that’s not so simple. The Social Practice Theory has for example shown the importance to go beyond attitudes, behaviours and choices of individuals and to focus on practices (seen as a set of materiality (e.g. infrastructures, vehicles), skills (how to make use of a transpiration mode) and meanings (images, perceptions of modes).

In other words it is important to convince people but even more to make some practices easy, desirable. In the case of cycling for example, infrastructures are crucial (safe, direct, etc.).

Urban sprawl versus re-urbanization: what is best? What is the role of medium sized towns?

Urban sprawl is associated with many negative impacts: land consumption, impacts on the landscape, high costs of infrastructures, automobile dependence, decline of core areas. Reurbanization has the advantage to address and mitigate these issues. It may need some specific policies (e.g. land purchase, new planning tools, participation) as in-fill development raises more issues that new developments (e.g. neighbours, historical heritage, etc.).

Medium sized towns are likely to play an important role as they combine the advantages of towns (proximity, services, shopping, etc.) with a scale that may address the residential aspirations of a wide part of the population (families, elderly, young de-cohabitating adults).

What proportion of mobility habits shift, recorded by studies hangs on - PA regulations -Spontaneous evolution in using new vehicles?​​​​​​​

It is difficult to answer this question as it depends on a lot on the contexts, regulations, etc. Regulations address the availability and the cost of parking, that have an important effect. The same can be said for mobility pricing (although with differences according to the case studies). Constraints are important but it is also crucial to provide efficient alternatives (public transport, cycling).

I am not sure to which extent using new vehicles is spontaneous. It requires investments either from the public or private sector or from individuals. Take for example the electric car: it requires infrastructures to recharge at home, at the work place, on the way, etc. Who is in charge to implement this infrastructure? The same goes for the e-bike: several cities in Switzerland subsidize the purchase of the e-bike to foster the demand but also the supply (shops, repair, etc.).

Check this link for an additional interview with Prof. Rerat on bike usage during COVID-19 crisis.