Today, the use of rails and trains in the traortation of goods and passengers has a special place and importance. Therefore, it is important to study the vibrations and the interaction between the rails and the wheels for the greater comfort of the passengers, to carry the load safely, to prevent deviation from the route, and also to reduce the breakdowns of the rails and the wheels. For this reason, the distances between the two rails in the straight path and the rail curve have been investigated as places where there is a possibility of vibration and impact. First, the motion on the rail seam was simulated in a straight line and was obtained using the conversion function of the rail motion equation and the wheel motion equation. Then the forces on the wheels and rails were calculated using the Hertz equation. The maximum amount of force at the joint spacing of different rails and different speeds was obtained by a computer program. . In the following, the same steps have been performed to calculate the force when moving on the winding rail track. In each step, vertical and lateral forces were obtained and the ratio of lateral to vertical force at different speeds was calculated to find critical speeds and speed of 90km / h was known as the critical speed at the turn. The result of these calculations can be used to optimize the construction of rails and wheels, the distance between joints and movement at safe speeds in turns.