Evaluation and Refinement of Minnesota Queue Warning Systems Status: CompleteReport Date: 06/01/2023 Summary: Vehicles coming to a standstill, or queueing, on a highway can cause hard braking. Similarly, shockwaves that are created when traffic speeds change quickly can cause a cascade of braking. These conditions create risks for rear-end and other crashes. Warning systems use real-time traffic data, vehicle sensors and algorithms that trigger traffic warnings on overhead message boards to alert drivers to conditions ahead. A queue warning system was previously installed on a crash-prone segment of I-94. Capitalizing on two years of data, researchers evaluated system performance and found crashes decreased 56% and near-crashes decreased 69%. The system, which is integrated with MnDOT’s existing traffic management technology, was then installed in a second location upstream from the original site. Devising a data-driven methodology to evaluate the newly placed system, researchers determined that the system is transferable to other locations, though additional calibration and fine-tuning may be needed. Final Deliverables: Evaluation and Refinement of Minnesota Queue Warning Systems (Report #2023-05) Improving and Expanding the Queue Warning System (Research Summary) Related Materials: Improving and Expanding the Queue Warning System (Blog Post) Related Research: Towards Implementation of Max-Pressure Signal Timing on Minnesota Roads Speed Notification System Warns Drivers Approaching Urban Work Zones Development of a Queue Warning System Utilizing ATM Infrastructure System Development and Field Testing