Five years ago, any discussion of 5G included a vision that we’d end up with smart cars that were all connected with a ubiquitous 5G network that was going to be built everywhere. We’re still waiting to see a real 5G network anywhere instead of the 4G LTE networks that are still being touted by every cellular company as 5G. The idea of a ubiquitous network capable of supporting smart cars died, but there is still an effort underway to use wireless technology to make car travel safer.

ITS America is an organization of 200 firms looking at the future of transportation, which includes technology firms, government transportation agencies, auto manufacturers, academic organizations, and others. ITS America is one of the leading proponents of connected vehicle technology, which is referred to as V2X (vehicle to everything).

A V2X system requires two components. First is an onboard unit (OBU) consisting of wireless radios and vehicle computer systems. The OBU is connected to sensors throughout the car but is also intended to make outward links. A roadside unit (RSU) is a radio unit along a roadway that communicates with vehicles. The RDU can be connected to a larger network, but that’s not mandatory.

The National Transportation Safety Board concluded recently that installing V2X technology in cars is on its “Most Wanted List” for transportation safety improvements. One of the promises of the technology is that an RDU installed at a dangerous intersection could communicate directly with cars and could reduce the number of collisions. RDX could also communicate the location of pedestrians to nearby cars.

An RDU can tackle the role of traffic cop at intersections and could change the timing of red lights based on current demand. An older study from the U.S. Department of Transportation (USDOT) estimated that 75% of all intersections in the country need improvements in traffic light timing.

Like any new technology, there is a chicken and egg issue. It’s unlikely that local governments will be interested in installing RDUs until enough cars have V2X technology. Car manufacturers don’t want to spend extra money on the technology unless the benefits can be explained to customers. ITS America estimates that the national cost to put RDUs at every intersection is around $6.5 billion—a big number, but not out of reach if it could significantly reduce death and damages from collisions.

The FCC has a role in this technology since it set aside a 5.9 GHz spectrum to use for the technology. A few years ago, the FCC took back half of the allocated spectrum because it wasn’t being used. The industry needs to find more uses for the spectrum, or cellular carriers will eventually be clamoring for the attractive bandwidth.

The USDOT is exploring the idea. The agency recently made a grant of $60 million for projects in Texas and Arizona to explore the RDU technology. One of the projects looks to “enhance safety, efficiency, and overall mobility for vulnerable road users at signalized intersections, emergency responders navigating through varying traffic scenarios, transit operators seeking efficient routes, workers operating within construction zones, and everyday motorists.”

It’s an idea that should have wide appeal. Everybody knows of a few intersections that are unsafe and that have an undue number of accidents. And every driver would love to stop waiting for a green light when there is no cross traffic. The idea probably requires a national solution since that would probably trigger car manufacturers to include the technology in new vehicles.