شناسايي دسته بندي و ارزيابي پارامترهاي موثر در مكان يابي VMS در بزرگ راههاي شهري

Identification, Classification and Evaluation of parameters affecting Variable Message Signs(VMS) Locations in urban highways.

Variable Message Signs have been used widely to maintain positive influence on driverʹs behavior and to improve traffic flow. Therefore deploying a Variable Message Sign should be based upon real needs of the network and traffic. One of most important characteristics of VMSs, which has considerable impacts on VMSʹs ability to inform drivers properly and in a timely manner, is VMS locations. In this article, first of all the information and messages that will be shown on the VMS board have been analyzed, then the most important parameters that affects VMS location and design, identified and then classified, and at last each of those parameters and itʹs required locating characteristics are analyzed. These parameters are in two major groups: local and message-driven characteristics.To prioritize the parameters a question and answers survey have been planned, required forms designed and it has been distributed between transportation professionals. After analyzing the returned survey forms, seven most important parameters identified; 1 Suggesting alternative route to drivers(before congestion areas), 2)alternative route suggestion (before known accident zones), 3) informing drivers to regular congestion zones 4) informing drivers to high accident rate spots 5) alternative route suggestion for various high demand traffic areas, 6) informining drivers to high demand traffic areas and 7) after major entrances into highways for Variable Speed Limit(VSL) schemes. Above parameters got the following scores respectively: 9.1, 8.1, 7.9, 7.9, 6.2, 6.1, and 4.8. It also recognized that the optimum distance to inform drivers before any of above parameters for parameters 1 to 6 is between 1 to 3 kilometers, and the optimum distance after entrance, in parameter no#7 is less than 1 Km.