Simulation models show that roadside information used to gap-meter mainline traffic near freeway on-ramps can reduce delays related to merging traffic by 17 to 27 percent.

Simulation of gap metering active traffic management tool.

Date Posted
03/20/2018
Identifier
2018-B01247
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Gap metering for active traffic control at freeway merging sections

Summary Information

This research proposes "gap metering" as a tool to manage freeway merging sections, which are common sources of peak-hour traffic congestion. Gap metering is a non-stopping, mainline version of ramp metering that uses dynamic message signs and flashing beacons to advise mainline traffic to yield sufficient gaps for merging vehicles.



Methodology



Detailed system design and control methods were created using the VISSIM modeling tool. Different combinations of driver behavior and headway distances were considered, accounting for gap metered traffic and non-gap metered traffic. Use cases included the I-894 corridor in Milwaukee, Wisconsin and the Riverside Drive segment of I-35 in Austin, Texas.

Findings

The results suggest the potential of using gap metering as an effective strategy addressing traffic congestion caused by merging traffic. Gap metering yields delay reductions of 17 to 27 percent, outperforming ramp metering alone. Gap metering and ramp metering combined may yield even greater delay reductions.

Goal Areas
Results Type
Deployment Locations