Analysis of over 100 cities across the globe illustrates a strong relationship between VKT (vehicle kilometres of travel) and urbanised area. As VKT can be used as a surrogate for vehicular emissions, this provides a method of estimating urban vehicular pollution. These emission rates have been incorporated with simple meteorological forcing into a box model to provide a generalised urban air pollution model for any city. The development and validation of the model is presented and its application as a simple planning tool discussed.