The technology that gives cars superpowers to see around corners and through walls won’t be on the first self-driving rides hitting the road in the next few years.

Vehicle-to-vehicle communication systems, known as V2V, are regarded as essential for fully automated travel, which could dramatically reduce traffic fatalities from around 40,000 in the U.S. last year. The tech enables cars to send signals back and forth to one another, improving their ability to foresee potential collisions and avert them.

Despite its promise, the tech is going nowhere fast. A push by regulators during the Obama administration to speed V2V to market has stalled under the Trump administration. Without rules requiring it, automakers including Ford Motor Co. are holding off on deploying $350-per-vehicle systems that aren’t effective unless most cars have it.

“Unless it gets mandated, nobody is going to put it on their cars,” said Glen De Vos, chief technology