The collision process of a pair of asperities on two opposing surfaces is modeled in frictionless sliding motion with an analytically traceable approach. Equations of a sufficiently general representation are derived for the contact force, the load-carrying capacity, and the motion resistance of the asperity collision. A system model of the contact of two nominally flat metallic surfaces is subsequently developed incorporating the effects of asperity microcontact collisions. Results of a general nature are presented of the load capacity and motion resistance of the contact system in sliding motion. The model and the results may provide a first-order approximation of the effects of the asperity collisions in a sliding contact system.