There has been a substantial growth of road traffic over the years and consequently,of air pollution caused by the vehicular exhausts,which is now considered as one of the primary source of urban air pollution.So the research of vehicular exhaust dispersions can serve the road construction,vehicle control,monitor assessment and decrease of air pollution over road.A comprehensive overview of the road vehicular pollution dispersion models is presented in this paper.The emphasis is on the progress together with the existing limitations of various models including Gaussian models,numerical models and statistical models.Then the accuracy along with the suitability in various conditions are compared.Subsequently,the review specializes at the dispersion models of urban street canyons.It points the primary difficulty of current model research existing at the simulation of the flow in urban street canyon,at the same time,introduces the progress in the simulation.At last,several crucial barriers in developing vehicular pollution dispersion models are presented,and the possible solution ways are also given.