Traffic jamming on hexagonal lattice

A traffic model on hexagonal lattice is studied. The moving objects are modeled as biased random walkers on hexagonal lattice. The hexagonal lattice traffic model is an extension of the square lattice traffic model proposed by Muramatsu et al. (Physica A 267 (1999) 487). The hexagonal and square models are compared. It is found that hexagonal and square models have a phase transition from freely moving state to jammed state at a critical density. The critical density of hexagonal model is greater than that of square model when the drift of moving objects is high. The difference between the critical densities of hexagonal and square models decreases when the drift decreases.