This research builds an integrated chain of models to compute the economic costs of population exposure to air pollution from roads. The framework uses data with a high geographical resolution (1 km x 1 km), a mobility module to simulate population movements, and a Gaussian dispersion model-based exposure model to evaluate population air pollution exposure and the related costs. This paper investigates the impact of two policies on La Réunion, a French island.: replacing old vehicles with electric ones and allowing flexible departure times for commuting trips.