The spatiotemporal dynamics of a damped sine-Gordon chain with sinusoidal nearest-neighbor couplings driven by a constant uniform force are discussed. The velocity characteristics of the chain versus the external force are shown. Dynamics in the high- and low-velocity regimes are investigated. It is found that in the high-velocity regime, the dynamics is dominated by rotating modes, the velocity shows a branching bifurcation feature, while in the low-velocity regime, the velocity exhibits steplike dynamical transitions, broken by the destruction of strong resonances.