How much safer, smoother, and more efficient could driving be if cars could communicate with traffic lights while approaching an intersection, get alerted to jaywalking pedestrians, or talk to each other while roaring down the highway at 65 miles per hour? A peer-to-peer wireless technology called C-V2X can warn vehicles about obstacles that cameras and radars might not catch, connecting them to their surroundings in a way that could eventually help them drive themselves.

A slew of tech companies, including Ericsson, Huawei, Nokia, and Qualcomm, started developing C-V2X (an abbreviation for the phrase “cellular-vehicle-to-everything”) in 2016 and are now showing it off in small demonstrations. Most of the demos involve people driving cars and trucks outfitted with special C-V2X chipsets and modems. The vehicles send and receive wireless signals 10 times per second and display certain types of information—such as warnings about oncoming pedestrians, storms, and accidents—as pop-up alerts on drivers’ windshields or dashboards.

The most recent C-V2X demonstration, which took place in Colorado on August 14, also connected participating vehicles to traffic lights, so drivers knew exactly when the lights would change colors. Eventually, the technology could route information between vehicles and bridges, toll booths, construction signs, and other roadside infrastructure.

Proponents of C-V2X say the data it delivers would help drivers avoid mishaps and would also ease traffic congestion, cutting down on greenhouse-gas emissions. While the most vocal supporters are tech firms that would profit from the adoption of C-V2X and subsequent sales of chips and related equipment and software, a number of automakers are also enthusiastic and seem to prefer it over more established vehicle technology.

Take Ford. Though the automaker has yet to commit to integrating C-V2X into upcoming cars, it supplied vehicles for three C-V2X demos so far this year and believes the technology will improve road safety and help cities manage traffic, according to Jovan Zagajac, who oversees Ford’s connected-vehicle initiatives. Ford also signaled support by joining the 5G Automotive Association (5GAA), a consortium of companies that helps develop C-V2X and advocates for its use.

Audi, BMW, Daimler, Honda, Hyundai, Nissan, and Volvo are fellow 5GAA members. However, the world’s second-largest automaker remains a holdout. Toyota, along with GM, favors a competing (and technologically incompatible) Wi-Fi-based technology called DSRC (for “dedicated short-range communications”). Companies began developing DSRC in the early 2000s, and Toyota has defended it as a “proven technology” that “has been out of the ‘testing and conceptual’ phases for quite some time.” Both Toyota and GM already offer DSRC in some of their cars and plan to roll it out more broadly over the next few years.

Toyota’s heft matters because the Trump administration has indicated it will let the auto industry select which connectivity technology to use instead of picking a winner itself. “Automakers are taking sides, and that will decide the technology [that connects cars], rather than a government mandate,” says Chris Armstrong, head of smart-mobility projects for Panasonic, which makes software that analyzes connected-car data.

Should consumers care which standard prevails? C-V2X boosters say the technology can do all the things DSRC does plus more, in part because it can piggyback on the constant improvements that operators make to their cellular networks. (Under C-V2X, short-range communications between vehicles in close proximity happen automatically, without relying on any cellular connection, but cars can also tap into surrounding mobile networks to talk to vehicles located farther away.)

The distinctions between DSRC and C-V2X may sharpen later this year, when telecom operators start deploying next-generation wireless networks known as 5G. Because 5G will use different frequency bands that have much more bandwidth than current cellular networks, it should—in theory—let cars exchange huge amounts of data far more quickly than they could today. That, in turn, would support autonomous driving because C-V2X-equipped vehicles could signal their intended actions to other C-V2X vehicles swiftly enough for them to react, says Nakul Duggal, Qualcomm’s vice president of product management.

“When we get to 5G, you’ll be able to know when a vehicle far ahead of you intends to change lanes or starts to brake even if it’s beyond your line of sight,” says Duggal. “There could even be special lanes where autonomous vehicles are allowed to travel really fast because they’re able to share information about incoming and outgoing traffic at great speed.”

Some organizations are so excited about the general idea of connected cars that they’re installing equipment that supports both standards now. That’s the case in Colorado, which has started equipping roads with wireless routers compatible with DSRC and plans to add C-V2X capabilities later this year in a bid to prevent accidents. The Colorado Department of Transportation also aims to outfit 2,500 of its vehicles with C-V2X and DSRC connectivity by the end of 2018. “We care about saving lives and strongly, strongly believe that connected-vehicle infrastructure will help us do that,” says Amy Ford, who heads the agency’s advanced-mobility efforts. “Since we’re not sure how this technology will evolve, we’re just making sure we’re creating an environment flexible enough to deploy both.”