In this paper, a two-dimensional grid based numerical carbon pollution model for the estimation of carbon pollutant concentrations in roads is developed. The simulations of carbon pollutants in roads with ventilated embankments have been presented. Based on a two-dimensional advection-diffusion transport equation, the modeling system incorporates the combined influence of both model input and environmental parameters. Absence and presence of forced convection are considered, with the provision of ventilations on the walls of embankment. Boundary conditions and environmental factors are varied to achieve the desired results. Carbon concentrations is approximated by using Godunov finite volume technique. The solutions of calculated carbon pollutant concentrations at different distances, both in the horizontal and vertical directions from the source are compared. The results suggest that the advection - diffusion model is satisfactory for simulating the effect of free and forced convection on carbon concentrations in roads with ventilated embankments.