This article studies the truck-induced airflow. The results of numerical investigations are used to assess the effectiveness of the installed hash symbol (#) shaped fence on the truck. The Reynolds-averaged Navier-Stokes equations are solved using the finite volume method. The computed distributions of the pressure and the air velocity as well as the computed aerodynamic drag coefficients reveal the effects of a fence on the aerodynamic performance of the truck. It is shown that the hash symbol shaped fence plays its role due to its aerodynamic characteristics, better than those of the original model. For various gaps, the optimal position and height of fences are discussed in the article.The experiments in a low speed wind tunnel provide the edidence for validation. The results of numerical investigations are used to assess the effectiveness of the installed hash hash (#) shaped fence on the truck. The Reynolds-averaged Navier-Stokes equations are solved using the finite volume method. The computed distributions of the pressure and the air velocity as well as the computed aerodynamic drag coefficients reveal the effects of a fence on the aerodynamic performance of the truck. It is shown that the hash symbol shaped fence plays its role due to its aerodynamic characteristics, better than those of the original model. For various gaps, the optimal position and height of fences are discussed in the article. experiments in a low speed wind tunnel provide the edidence for validation.