Development of a Queue Warning System Utilizing ATM Infrastructure System Development and Field Testing Status: CompleteReport Date: 06/16/2017 Summary: Two prototypes for an active traffic management (ATM) queue warning system were developed and deployed on two Twin Cities freeways. At one location, the system produced a 22 percent decrease in crashes per vehicle miles traveled and a 54 percent decrease in near-crashes. While the queue warning system represents a cost-effective option for improving highway safety, a longer trial period of two to three years is needed to make sure that the system provides sustainable benefits. Final Deliverables: Report #2017-20 Research Summary Related Materials: Related Research: