In 1998,[REF] Kerner found out that in real field traffic data the emergence of a wide moving jam in free flow is observed as a cascade of F → S → J phase transitions (Figure 9): first, a region of synchronized flow emerges in a region of free flow.
To further illustrate S → J phase transitions: in Kerner's three-phase traffic theory the Line J divides the homogeneous states of synchronized flow in two (Figure 8).