The government hopes its plan to make cars “talk” to each other in five years will prevent thousands of traffic accidents and save lives. But this technology also raises questions about consumers’ privacy and security.

Under the new rules proposed Tuesday by transportation officials, the auto industry will have to equip cars with technology that would allow the vehicles to share information with other cars on speed, location, direction and other key data.

Cars also will communicate with traffic signals and other parts of the transportation infrastructure.

The combination of vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) connectivity has the potential to reduce 80 percent of non-impaired crashes, says Mark Rosekind, administrator of the National Highway Traffic Safety Administration, which is part of the Transportation Department.

"Given that traffic fatalities increased by 7.7 percent in 2015 and continued trending upward over the first half of 2016, the importance of applying innovative technologies to improve safety cannot be overstated," said Marshall Doney, President and CEO of the American Automobile Association (AAA). "We need tested technologies, like DSRC V2V communications, to help reverse this troubling trend."

The auto industry is looking at the proposals, as are consumer groups and others. There is concern that car-to-car communications over a wireless network could be hacked or otherwise interfered with, and result in crashes, even as the technology prevents other incidents. And there is the issue of privacy, since a car’s location and other key data are being shared.

“We’re hopeful that this technology will help prevent crashes and save lives, alongside proven built-in safety features like automatic emergency braking,” said William Wallace, policy analyst for Consumers Union, the policy and mobilization arm of Consumer Reports.

“But vehicle-to-vehicle communications must be secure as Fort Knox," he added. "Automakers must be required to meet baseline, enforceable standards to protect both privacy and security as they roll out this technology. Communications should be protected through strong encryption, and security measures should be seamlessly updated so that consumers don’t have to worry about getting into a crash because their car has been hacked."

Transportation officials say the proposals are structured in a way to foster cooperation among automakers, while protecting consumers and inviting innovation.

To protect against outside interference or snooping, the DOT proposes that all communication between cars and with traffic infrastructure be encrypted. The system also will not share info that can be linked to individuals or their vehicles.

“This is a safety tool, not a data gathering tool,” explained Rosekind.

Wallace of Consumers Union said the agency is considering the right questions, but the proposed rule doesn't fully address the privacy and security risks that accompany connected vehicles.

Other groups, including Alliance of Automobile Manufacturers, are also studying the proposals.

"We will review NHTSA’s proposed rule on V2V communications to see how it complements other advanced systems that are starting to be included in a growing number of new automobiles,” said Gloria Bergquist, a spokeswoman for the group. “The Vehicle-to-Vehicle (V2V) and Vehicle-to-Infrastructure (V2I) communications…can complement crash-avoidance features like forward-collision warning and automatic emergency braking on sale today.”

She added that “V2V systems can provide another form of information about other vehicles or road hazards at greater distances and around corners.”

The DOT expects it to take a year to get to a final V2V rule. Once finalized, automakers would be expected to begin implementing the technology on new cars two years out, with a 100-percent compliance expected two years later.

In other words, there is about a five year horizon before all new cars would be equipped with this ability. The DOT anticipates that there would be a strong aftermarket interest in retrofitting the technology to older cars, and it says that work is already underway to develop a similar policy for heavy-duty trucks.