A vehicle-to-vehicle wireless network could improve safety by communicating warnings, but the benefits depend on broad deployment and acceptance by the public.

That’s the message from the Government Accountability Office, in its analysis of ongoing research into V2V communications.

As a field test of V2V communications in Michigan nears conclusion, the National Highway Traffic Safety Administration is considering what to do next. Among its options: a proposal to require V2V communications equipment on new vehicles.

The leaders of the House Committee on Science, Space and Technology, as well as transportation legislators, asked GAO for an analysis of V2V technology and testing.

In its Nov. 1 report, the agency said researchers and the auto industry anticipate significant safety benefits from V2V. But the benefits will depend on the technology being broadly deployed, and on drivers responding properly to the warnings they receive.

V2V communications can transmit information on speed and location to warn drivers of an impending collision or the need to slow down.

Experts say these wireless warnings can provide a quantum leap in highway safety.

The Department of Transportation estimates that V2V and vehicle-to-infrastructure communications can reduce non-impaired heavy truck crashes by more than 70%.

The technology is being tested in a variety of settings, including a large field study conducted by the Department of Transportation and the University of Michigan Transportation Institute.

That study is due to be wrapped up by February, but GAO said deployment depends on what NHTSA decides to do. That decision is expected before the end of the year.

GAO reports that deployment must overcome a number of challenges.

More work needs to be done to ensure that V2V technical and management framework provides security, the agency said. Also, questions about the radio-frequency spectrum that the system uses must be resolved: if the spectrum is to be shared with other users, that cannot impair the performance of V2V technology.

Other questions: will drivers respond properly to the warning messages they receive, what are the liability issues and what about privacy.

“DOT is collaborating with automobile manufacturers and others to find potential technical and policy solutions to these challenges,” the agency said.

GAO also said that automobile companies say it is hard to estimate V2V component costs at this stage because there are too many unknowns, such as the size of the market.

The agency warned that while the component costs may not be much in relation to the cost of the vehicle, the operational costs of providing security could be significant. And it is not clear who would pay for the security – consumers, manufacturers or the government.