It’s dark on the back road as a motorist speeds toward the intersection. Up ahead, the stop sign blends with the night and in seconds a deadly crash occurs. According to the U.S. Department of Transportation, more than half of all roadway fatalities occur on rural roads. Now, engineers at UTSA are building and testing a system that will detect vehicles, improve the visibility of stop signs, and prevent deaths.

“Stop signs on rural roads are difficult to notice, and this leads to dangerous accidents,” says Ayetullah Biten, a doctoral candidate in the Department of Electrical and Computer Engineering.

Rural roads account for 70% of the nation’s byways and the location for 54% of all fatalities, according to the Federal Highway Administration. Without access to a power supply, they are more likely than other roads to lack signals and active traffic signs.

To improve driver safety, Sara Ahmed and Samer Dessouky, professors in UTSA’s College of Engineering, created a low-cost, self-powered intersection detection and warning system to alert rural motorists about potential dangers. The next-generation stop sign uses a multipixel passive infrared sensor that detects a vehicle as it approaches an intersection. Once the vehicle is within the sensing range, a signal beacon triggers the stop sign’s flashing system.

“The sensor observes thermal signatures and processes them to detect passing vehicles,” says Zachary Balcar, an electrical and computer engineering master’s student. “It distinguishes the vehicle’s direction of travel, estimates the velocity of its thermal signature, and determines the classification of the vehicle.”

Overall, the smart system has a 90% vehicle detection rate and a vehicle classification accuracy of 72%. Compared to current traffic sensing technologies in urban areas—such as magnetic loop inductors, video image processors, and microwave radar—the new system consumes less power and offers better accuracy. The new technology is also much less expensive to produce. Current safety systems can cost as much as $5,000. UTSA’s detection technology promises to be a fraction of the price—at $60 to $100 per unit.

“Our off-roadway system can be installed on urban or rural roads completely independent of the utility power grid, because it is powered by small solar panels and functions in all weather conditions,” Ahmed says.

The low-power rural intersection detection and warning system was developed with support from the Connect program, a collaborative research program that is cofunded by UTSA and the Southwest Research Institute.

The project team has filed an invention disclosure for the system, which was recently recognized nationally by the American Road and Transportation Builders Association.