This paper presents a method to integrate the Dynamic Late Merge with a merge metering via wireless communication at the downstream taper area of a work zone, termed as Dynamic Merge Metering Traffic Control System (DMM-Tracs) for highway work-zone bottlenecks. The architecture and communication system for the DMM-Tracs, including system components, communication technologies and operation mechanism, are introduced. With this system, the merge metering control will be activated depending on the volume detected at an upstream location of the work-zone bottleneck. If the thresholds of control parameters are met, a merge metering signal installed at the taper area will be activated and approaching vehicles will be informed of the metering situation through flashing signage or changeable message sign installed in the advance areas of the work zone. To reduce enforced merges and potentials of merge conflicts, the control scheme will be adjusted on the real-time basis depending on the detected traffic conditions. This potentially increases the efficiency with which the traffic is discharged into the open lane inside the work zone. A portable controller is the brain" of the DMM-Tracs System to receive data from detectors, process the data, and control the merge metering signal via wireless communications. The efficacy of the DMM-Tracs is evaluated via a micro-simulation test bed with the state-of-the-art microscopic simulation software VISSIM. Meanwhile, the volume threshold values are also determined via the simulation. The simulation results indicate that higher closure percentage of the bottleneck, more applicable the DMM-Tracs.
Abstract