A co-financing model for the mitigation of highway runoff pollution

Lígia Costa Pinto

University of Minho, Portugal


Lígia Costa Pinto is Associate Professor with habilitation in Economics at the University of Minho and full member of NIPE. Has a PhD in Economics from the University of South Carolina, USA. Her research interests focus in applied microeconomics. In particular, the application of experimental and behavioural economics into the areas of the environment and health. She has published extensively in international journals such as: experimental economics, contemporary economic policy, games and economic behaviour, journal of environmental management, journal of cleaner production, and the international journal of life-cycle assessment, among others.
She was invited researcher at the University of Central Florida, Orlando, and the University of California Riverside, in the USA, and a visiting scholar at the University of Porto, Universidade Católica da Beira-Mozambique, and the Universidade Nacional de Timor Leste.
Her teaching experience is vast but mostly concentrated in the area or environmental economics, natural resource economics, and energy economics.


The water that precipitates and migrates through road platforms results in a polluted runoff that is forwarded to the surrounding waters bodies and ecosystems (EPA, 2015). The associated negative impacts go beyond the natural environment, since they affect the health and wellbeing of the populations (Liyanage and Yamada 2017). This problem is of the utmost importance given the increasing need for mobility created by population growth. This unbalance demonstrates the need for a sustainable management of runoff with the inclusion of economic, social, cultural and environmental dimensions. Engineered and Nature Base Solutions (NBS) have been proven to effectively contribute for the control of runoff pollution, while protecting natural resources and maintaining good public health (Hvitved-Jacobson and Youssef, 1991; Zhou, 2014). However, their implementation involves high investments, and important maintenance efforts, leading to a discussion about who should be financially responsible. The present research focused on analysing existent knowledge, from different disciplinary areas, on highway runoff pollution and associated control measures, and eliciting the perception of the population regarding runoff externalities, and their availability to participate, actively and financially, in the implementation of management systems that mitigate this type of pollution effects. To our knowledge the co-financing model here proposed constitutes a novel approach to internalize highway runoff externalities involving the State, the concessionaires and users. A case-study on a 279-km Portuguese Highway is presented as a basis for a co-financing model. Runoff pollution load was estimated for quality indicators (TSS, COD, Zn, Cu, Pb), and the total cost of infiltration trenches, sand filters, bioretention filters, wet basins, dry basins and constructed wetlands systems was computed for four catchment scenarios. The effect of the equivalent catchment size and system type on the total cost was evaluated. The users ’Willingness to Pay’ (defined as pay-per-user and availability to participate actively and financially) was assessed through a survey (1192 responses). A proposed co-financing model suggests that citizens will participate up to 36.8% of the constructed wetlands cost. This multidisciplinary approach results in potential outcomes that include a legal framework, proven technical solutions, and users’ environmental responsibility. Thus, this research contributes to fill the gap between the legal framework, proven technical solutions, and users’ environmental responsibility.