Are shocks in conserved driven single-file motions with bottlenecks universal?

Driven single-file motion sets the paradigm for wide variety of one-dimensional directed movements, ranging from intracellular transport and urban traffic to ant trails and controlled robot swarms. Motivated by the phenomenologies of these systems in closed geometries, regulated by number conservation and bottlenecks, we explore the domain walls (DWs) or shocks in a conceptual one-dimensional cellular automaton with a fixed particle number and a bottleneck. For high entry and exit rates of the cellular automaton, and with {sufficiently large} particle numbers, the DWs formed are independent of the associated rate parameters, revealing a {\em hitherto unknown universality} in their {\em shapes}. In contrast, the DWs do depend upon these parameters, if they are small, and hence have nonuniversal shapes. Our predictions on the DWs are testable in experiments.