It is a crucial technological choice: Cars are increasingly connected, and the autonomous vehicles that will arrive in the future must have a way to communicate with each other and surrounding infrastructure. But even before self-driving cars hit the streets en masse, there are enormous benefits to be had. Federal transportation officials estimate that, once widely deployed, such communication systems will prevent or mitigate up to 80 percent of all non-impaired collisions and address thousands of fatal crashes per year in the United States.

The auto industry is divided over the standards.

General Motors has embraced DSRC, and it’s already a standard safety feature on Cadillac CTS sedans. Toyota and Volkswagen have also committed to make DSRC systems standard equipment on new cars beginning next year. On the other side are brands, including Ford, BMW and Mercedes-Benz, that have joined the chip maker Qualcomm, cellular providers and others to form the 5G Automotive Association, which is pushing the C-V2X standard.

Regardless of the standard that’s settled on, vehicles will be able to directly communicate with one another, allowing them to warn of collisions even when drivers cannot see each other. And such systems will allow valuable safety information to be shared from other sources: Instead of a sign warning that “bridge ices before road,” the bridge can warn drivers when ice has actually formed, and traffic lights will be able to manage traffic to minimize delays and clear the way for emergency vehicles.

But there are important differences.

DSRC has been around much longer, and most car companies have developed and tested systems based on the standard. The Federal Communications Commission ruled that a chunk of the wireless radio spectrum would be restricted to the DSRC standard beginning in 2003, and in 2016 the Obama administration proposed a rule that would mandate phase-in of DSRC in new cars and light trucks starting in 2021. The National Highway Traffic Safety Administration said systems to prevent collisions at intersections alone could save some 1,300 lives a year.