• A road pricing policy to improve equity is proposed. • The proposed road pricing system is based on differentiated charges for origin/destination pairs. • Charges are based on relative accessibility between zones. • Tests have been carried out on a sample network and on a full-scale network. This paper proposes a road-pricing policy to enhance equity, evaluating both transport and social aspects and using an optimisation model to solve the problem. This policy differentiates road charges based on the origin of the trip (the residence or domicile of the vehicle owner), considering the availability of public transport services. The aim is to provide higher charges for users who have good public transport services to travel to the priced zone, while charges are reduced or eliminated for those who have no alternative but to use a car. This policy aims to improve equity, as public transport is primarily funded by the community but is not available with acceptable levels of service for all origin–destination pairs, and therefore, for all citizens who need to travel. In this paper, a road pricing optimisation model is proposed based on minimising the variance of a multimodal accessibility measure. The problem is solved with a multistart generalised gradient algorithm. The proposed methodology was applied to a small-scale test network and a full-scale network. Numerical results have shown the validity and applicability of the methodology, even for large-scale networks.
Mariano Gallo (2026) studied this question.