Abstract: A hydrostatic force/displacement measuring device measures the force and displacement exerted by a rotating tire in soil/aggregate. The measuring device has a hydrostatic actuation assembly having a pressure plate at near surface depths of soil/aggregate to provide hydrostatic pressures in a liquid representative of force and displacement created by the downward forces exerted by a rotating tire in the soil/aggregate at the near surface depths. A hydrostatic hose transmits the hydrostatic pressure forces in the liquid to a surface manifold assembly. The surface manifold assembly receives the hydrostatic pressure forces and has a gauge providing visual readouts of the hydrostatic pressure forces representative of the downward forces. The surface manifold assembly also has an axially displaceable piston defining an interface chamber. The piston is connected to an electronic sensor to provide visual readouts representative of displacements caused by the downward force.