Grid locks and traffic jams are always annoying problems in urban area, one may ask as to which factors affect the creation of gridlock jams, and how do each of the factors relate and interact with each other? Understanding grid locks is a very important problem in cities with heavy traffic loads. But traffic in the urban environment with a grid is complicated situation, analytical methods are almost impossible to solve them. In recent times cellular automata based simulations of traffic flow have gained considerable importance. A one-dimensional Cellular Automaton (CA) model with periodic boundary conditions representing a single lane freeway was introduced into traffic theory by K. Nagal and M. Shreckenberg in 1992.
Our simulations are implemented with one-dimensional traffic CA rules along the streets and two-dimensional CA rules for the intersections to regulate the behavior of the grid traffic. We present the characteristics and phenomena of a two-dimensional grid traffic with java program(JDK1.2.2). Using a 3D software POVRay for Windows and the calculation result from the java program we produced movies of a virtual city in 3D.