Evaluation of Reversible Lane on Inbound of Chalong Rat Expressway

Abstract

Due to traffic congestion on the Chalong Rat inbound expressway during rush hour in the morning, EXAT has daily average traffic volume of 1.9 million trips per day resulting in vehicles accumulation along Rama 9 Road to Ramindra Road. While the traffic was light in the opposite direction. EXAT started using reversible lane to decrease congestion on the inbound expressway from the Sta.12+100 to Sta.7+700. The problem must be resolved with reversible lane. From reviewed and researched the traffic volume to improved traffic operations. The research, inbound expressway has a capacity of approximately 7,849 vehicles per hour and 2,540 vehicles per hour for outbound, 76:24 as ratio, which is suitable for “Reversible Lane”, Its use is most applicable on multi-lane roadways with a directional imbalance. EXAT moved the exit from Sta.7+700 to Sta. 6+400 in order to pass beyond the Rama 9 Road which has high congestion. In accordance with the principles of Reversible Lane to mitigate peak period congestion, the barrier exiting has been improving from 20 meters to 35 meters which is the highest width that can be performed for Sta.12+100 and Sta. 6+400. The structure of exiting was constructed and redesigned to be slippery and easy to use including road signs at kilometer markers 500 and kilometer markers 1000. For the traffic safety, 6 road signs with variable message sign and matrix sign was designed to be LED light banner to warn the user in the outbound expressway then announced in the Government Gazette for Reversible Lane on the expressway. EXAT has lined the traffic cones along the road for over 6 kilometers and vehicles with flashing lights at the entry point for clear observation. This starts between 6.30 am to 9.00 am from the evaluation this method reduces the congestion and increases the level of service by flow up 10.8%, Travel time decreases from 15.7 min to 13.3 min. in mainline and 8.3 min. in reversible lanes. Economic benefit 11.4 million baht per kilometers per years or 36 million baht per year.