Longitudinal traction and braking response of a tire is an important performance feature for vehicle applications.  This presentation examines basic tire mechanics issues governing tire longitudinal response to drive and brake torque changes in dry surface conditions.  The role of footprint contact response to longitudinal force change in traction and braking is examined.  The interaction of local contact phenomena and global tire response is evaluated.  The influence of tread pattern features on contact behavior is illustrated.  Both experimental and computational evaluations of footprint response are presented.  The evolution of mu-slip force development is examined and related to local contact behavior.  Aspects of tire longitudinal response for steady state as well as transient conditions are examined.  The significance of synergistic application of both experimental and computational tools in tandem is illustrated in clarifying the basic mechanics of tire longitudinal response.