Comparative Evaluation of Mobile Probeand Fixed Sensor for Traffic Report System : A Case Study on Kanchanapisek Expressway (Bang Phli - Suksawat)

Abstract

The evaluation of Mobile Probe utilization for reporting traffic conditions system on expressways was conducted by focusing on the accuracy results of using probe to report traffic conditions of expressway comparing with the fixed sensors which were installed onsite and more costly than probe. The Kanchanapisek Expressway (Bang Phli-Suksawat) with the total length of 22.5 Km was selected to be a study area since all essential traffic data for constructing and calibrating the simulation model are available in this route due to prior implementation of the fixed sensors network for EXAT ITS corridor project. The Microscopic Simulation Model developed by AIMSUN 7.0 program was employed to analyze and evaluate the performance of Mobile Probe for reporting traffic conditions. The Traffic Simulation Model was calibrated and validated with 85 percent of accuracy by using traffic flow rate, average speed, and traffic density measured onsite by the ITS sensor network system. The traffic volumes at relevant toll plaza were gathered from Revenue Audit Database and used as input traffic parameter.  The results show that only 3-5 percent of mobile probe data can be represented the average vehicle speed of road users with 85 percent of accuracy. Beside, others issues regarding the utilization of mobile probe comparing with fixed sensors have been discussed on matter of the transportation engineering basis.