Phase transitions and critical phenomena are investigated in the two-dimens
ional traffic flow on the triangular lattice numerically and analytically,
The two-dimensional traffic model on the square lattice is extended to the
traffic flow on the triangular lattice where the three roads cross on a sit
e. It is shown that the jamming transition between the freely moving and ja
mmed phases depends on the configuration of car moving directions, It is fo
und that the three distinct jamming transitions occur: the conventional jam
ming transition to the kink jams, the jamming transition to the chaotic jam
s, and the jamming transition to the oscillating jams, The conventional jam
ming transition to the kink jams is analyzed by the use of the linear stabi
lity theory and the nonlinear method. The coexisting curve between the free
ly moving and jammed phases is calculated from the solution of the modified
Korteweg-de Vries (KdV) equation. (C) 1999 Elsevier Science B.V. All right
s reserved.