Abstract
All productive activities have associated a set of external effects with the same diverse nature. Considering transport as an economic production process makes it possible to account for its overall balance both in terms of the products and the resources it consumes. Road transport involves a series of costs that can be separated internally when they are borne by the user, the infrastructure operator, or the transport service and externally, which are not those paid for by the user and may affect society. In this paper, an economic engineering method (EEM) to internalize external congestion and CO2 emission transport costs in the Tunisian case to quantify the environmental impact of atmospheric pollution emissions associated with fuel-based energy carriers (negative transport externalities) is used. The method is applied in Tunisia to compare the potential impact of other policy options and the need to rebalance existing policies, develop a central transport network, develop research and development programs, and take steps to complement existing legal measures. The results allow for the quantification of congestion and CO2 emission in road transport to discuss some marginal and policy implications in sustainable road transport. Advances in the internalization of transport externalities have made it possible to establish a more suitable framework for dealing with many transport problems.