Abstract
The asymmetric simple-exclusion model on two-crossing one-dimensional lattices is considered for studying shock formation and traffic jams induced by a crossing. The condition for shock formation is derived for car densities p1 and p2 of the first and second street. The phase diagram and the dependence of the traffic current on the car densities are shown. We compare the present result with that of a car accident. Also, we investigate the shock formation induced by both a crossing and a car accident. It is found that the dynamical transitions occur successively with increasing car density. The phase diagram is shown.