With early warning about traffic delays ahead of them, highway drivers can adjust their speeds to keep traffic flowing smoothly and avoid dangerous sudden stops that often result in rear-end crashes. Nationally, the U.S. Department of Transportation has made the development of smart speed harmonization and queue warning systems that can provide these warnings a high priority.
As part of this national effort, researchers at the U of M’s Minnesota Traffic Observatory (MTO) are working to establish a testbed for developing and testing connected vehicle technologies and applications, including speed harmonization and queue warning, as part of a project funded by the Roadway Safety Institute.
“A lot of people in the federal government [and] academia are creating new connected vehicle technologies,” says MTO director John Hourdos. “They will need a place where they can test them in a real environment—in a very interesting environment.”
The testbed is building on the MTO’s permanent I-94 field lab, which consists of three rooftop locations equipped with surveillance cameras and machine-vision sensors focusing on a high-crash area of I-94 in Minneapolis.
The area experiences more than 100 crashes annually—many are rear-end crashes resulting from a failure to stop or too little headway. Since 2003, the field lab has been capturing detailed data on hundreds of crashes, including sensor data, video records, and MnDOT control actions.
This project is adding two basic elements to the current I-94 lab: high-resolution radar sensors, which will allow the researchers to collect vehicle trajectories, and a communication element in the form of roadside units that transmit radio signals compatible with the dedicated short-range communications (DSRC) standard.
So far, researchers have been deploying and testing the sensors in different locations, allowing them to better gauge radar accuracy and improve speed detection. They can also compare the new sensor data with that from existing camera locations for real-time observation. In addition, they’ve upgraded their wireless communication and used the improved sensor data to create and test a new version of the queue warning application.
Next steps include deploying additional sensors, conducting live field tests of the infrastructure-based queue warning application, and developing a vehicle-to-infrastructure (V2I) version of the application.
Ultimately, Hourdos says, the result of this project will be a fully functional connected vehicle testbed uniquely situated to attract freeway safety-oriented V2I and vehicle-to-vehicle safety application development, implementation, and evaluation projects.