According to the Federal Highway Administration, 54 percent of all US traffic fatalities occur on rural roads. Many of those accidents are in turn caused by drivers not seeing stop signs. New technology could help, by illuminating flashing lights on those signs in response to approaching vehicles.

Developed by a team led by professors Sara Ahmed and Samer Dessouky, from The University of Texas at San Antonio, the system is powered by an integrated solar panel. This allows it to run completely off-grid.

As a vehicle approaches a stop sign that's been equipped with the technology, a multi-pixel passive infrared sensor detects the trajectory and velocity of that vehicle's thermal signature. The sensor can also ascertain what sort of vehicle it is.

Based on that data, a red light above the sign starts flashing to alert the driver – it does so soon enough to give them time to safely stop, based on their current velocity.

In tests conducted so far, the system has demonstrated a vehicle-detection accuracy rate of 90 percent, which is actually better than that of existing car-detection technologies such as magnetic loop inductors, video image processors and microwave radar. Additionally, the U Texas setup requires less power, and should be cheaper to manufacture – whereas conventional safety systems reportedly cost up to US$5,000 a pop, the new one could sell for as little as $60 to $100 per unit.