“…For previous work focusing on the description of jam formation as a nucleation process, see [11,12,13,14]. It is related to phase separation and metastability in low-dimensional driven systems, a topic which has attracted much recent interest [15,16,17,18,19]. Metastability and hysteresis effects have been observed in real traffic, see, e. g., [20,21,22,23,24,25,26] for discussion of empirical data and the various different modelling approaches.…”