The knowledge on vehicle stability, ride comfort and performance is critically significant on off-road vehicle traversing over irregular terrains. The subject of off-road vehicle analysis from the terrain–tire interaction perspective has always been from complex domains of engineering owing to the elasto-plastic behavior of deformable terrain and nonlinear vehicle dynamics. This paper is dedicated to synthesize the induced shock and impact force as affected by the obstacle geometric factors during tire-obstacle collision dynamics. To this end, various obstacle shapes were included at different depths to determine at which geometric configuration, the greatest and lowest impact forces are induced. Aiming this, the soil bin facility equipped with a single-wheel tester of Urmia University was adopted to carry out the needed experimental tests while the operational condition of the wheel traversing was absolutely controllable (i.e. slip, forward speed, wheel load, etc.). The developed model also was verified by the experimental data and the obtained results showed that the greatest impact force both at the longitudinally and vertically oriented directions were obtained by the triangular shaped obstacle at the greatest height while in contradictory to the expectations, the lowest values were obtained for the trapezoidal obstacle when compared with the Gaussian shaped obstacle. The findings will serve future studies as a functional source to develop improved vehicle designs to interact with differently shaped obstacles and various operational conditions for run-off-road vehicles traversing over irregularities.