How to design publicly acceptable road pricing? Experimental insights from Switzerland

Road based motorised transport has many important societal benefits but also results in various negative environmental externalities such as CO2 emissions or noise and local air pollution. Road pricing is widely regarded as an efficient and effective policy instrument for mitigating these externalities. In reality, however, it is politically controversial because it is associated with high opportunity costs and concerns over distributional effects. We examine whether and how designing road pricing in particular ways could help in achieving public support by implementing a conjoint experimental design using original data from a large, population-representative survey in Switzerland. Additionally, we test whether providing information about environmental benefits of road pricing increase support. We find that support for road pricing tapers off quite strongly when policy designs approach cost levels required for substantive mitigation of externalities and that preferences are robust against experimental manipulation. On the other hand, redistributing revenues towards public transport and green infrastructure increases support substantively at lower cost levels. The findings suggest that there are limits to how policy design and environmental communication can help overcome political feasibility barriers for road pricing. One should therefore focus on additional aspects to increase support such as policy sequencing.