Abstract: First, a traction/brake subsystem nonlinear equation of longitudinal dynamics is deduced for the heavy-duty vehicular cruise control systems on the low-speed condition. Based on the equation, a feedback linearization method is utilized to convert the nonlinear system into a linear controllable normal form. Second, in order to eliminate the influence of control time delay in the nonlinear brake subsystem, a new feedback linearization transformation based on the nonlinear SMITH predictive theory is proposed. By adopting the new transformation, not only the control time delay can be compensated for effectively, but also the conversion of linear controllable normal form is realized. At last, based on the linear controllable form of traction/break system respectively, two controllers are designed to obtain precise acc/deceleration tracking on the low-speed condition.