In this paper we propose a grid simplifying method for road networks which preserves the structural patterns.The proposed approach firstly identifies the grid structure

and then merges grids contained by other grids and aggregates these grids into clusters according to their connectivity.The proposed method simplifies grids according to the principle of information minimum loss that is characterized by the grid index

the principal direction

and the elongation index.Two road datasets of Zurich and Wuhan were selected to evaluate the validity of the proposed method.Experimental results show that this method well preserves grid-like pattern.The simplified results provide a good data source for visualizations on small screen devices

multiple representation

and progressive transmission.