Ways to reduce vibrations at the tractor operator’s workplace in the unit with a trailer by improving the design of the suspension cushioning system are considered. Analysis of existing types of suspension systems shows that the most effective, in terms of reducing vibration loading, are active and semi-active systems. To reduce the vibration level at the tractor operator’s workplace in an aggregate with a trailer, an active seat suspension design has been developed. It includes a system of sensors and actuators that allow the current stiffness and damping of structural elements to be highly efficient in controlling the tractor operator’s workplace. To assess the effective use of the developed design, and compare it with the efficiency of the serial seat suspension, road tests were carried out. The tractor-transport unit in the tractor Belarus-1221 and the trailer 2PTS-4.5 with the serial and experienced suspension design were chosen as the object of research. During the field tests, the acceleration values were determined for the operator’s seat, the cab floor, the front and rear axles of the tractor. The test results showed that the developed technical solution allows reducing the vibration acceleration levels by 12-18% in comparison with the serial design.