Accurate analysis of electromagnetic wave propagation in tunnels has important applications in the areas of mobile and wireless communications. In this paper a fully vectorial finite element base propagation model is developed for blocked straight and curved tunnels. Effect of different vehicles, location of vehicles and number of vehicles inside tunnels is analysed. It is shown that the basic propagation loss inside tunnels is mainly determined by the number of vehicles and their size. Location of vehicles have influence on radio wave propagation only in curved tunnels.