Assessment of Traffic Problem Solving by Means of Switching Traffic Directions Phaya Thai interchange, Si Rat Expressway Case Study

Abstract

The Expressway Authority of Thailand (EXAT) was keep collects traffic information on the expressways in order to managing and solving overall traffic problems on expressway. A case that we are focusing on is Phaya Thai interchange (Direction to Pracha chuen, outbound) Si Rat Expressway during evening peak hours (5.00 – 7.00 PM), there are a large number of vehicle traveling from downtown to uptown so that it a cause of the accumulated queue length about 5 kilometers back to Asoke Toll Plaza and accidents occur from car scrape into the lane. The problem of accidents are consistent with the physical characteristics which are merging of 2 directions, namely Asoke direction with Bang Khlo directions heading to ngarmwongwan. Due to the aforementioned problems, the EXAT has implemented traffic management by switching traffic directions to solve the accumulated queue length problem By Using traffic staff to managing traffic between Asoke direction with Bang Khlo directions in every 5 minutes. As a result of the implementation of measures, it was found that at evening peak hour (16.00 – 19.00 pm) flow rate from Asoke direction was increase about 8.56% and the average number of queue length also decreased about 38% and from Bang Khlo direction flow rate was increase about 7.77% and number of queue length was decrease about 21.1%. Therefore, from this research has improved queue length and better traffic flow rate.