Road sign system with course restoration function

In this paper we proposed a mathematical model and its algorithm to build the optimum road sign system, which kept the drivers in the original course. We assumed that the guide sign elements were classified into place name, route number and their combination types, and that these signs were posted only at the entrance of intersections. Furthermore we defined the Straying Index as an expression of drivers straying, and proposed a method for minimizing the total Straying Index of all OD (Origin and Destination) travel. In this method, the total Straying Index of drivers was taken as the objective function, and the number of links, where signs were to be posted, and the number of displays for one direction on the signboard were treated as the restrictions. Finally, we solved this problem using dynamic programming, and extracted some properties of the sign type, regarding such as place name, route number and their combination through the analysis of a small network example.