Abstract: A method and apparatus for measuring and indicating limiting values for driving and braking vehicles in which a measuring wheel can be raised and lowered from a conventional wheeled vehicle to engage and disengage a substructure. The wheel is driven with a predetermined slip in relation to vehicle speed and the resulting loads detected by suitably mounted transducers. The signals produced by the transducers are combined in an electronic unit and displayed to indicate the braking force number, the coefficient of friction and resistance to rolling.