• T = Weight of the towing vehicle including the vertical load on the fifth wheel;
• R = Weight of the semitrailer;
• U = That part of the semitrailer weight which is directly transmitted to the fifth wheel.
• g = Gravitational acceleration; 9.81 m/s2;
• D-Value = Theoretical load for the determination of the theoretical horizontal dynamic force between towing vehicle and steering axle trailer;