U.S. DOT advances deployment of Connected Vehicle Technology to prevent hundreds of thousands of crashes

Proposed rule would mandate vehicle-to-vehicle (V2V) communication on light vehicles, allowing cars to ‘talk’ to each other to avoid crashes. Citing an enormous potential to reduce crashes on U.S. roadways, the U.S. Department of Transportation issued a proposed rule today that would advance the deployment of connected vehicle technologies throughout the U.S. light vehicle fleet. The Notice of Proposed Rulemaking would enable vehicle-to-vehicle (V2V) communication technology on all new light-duty vehicles, enabling a multitude of new crash-avoidance applications that, once fully deployed, could prevent hundreds of thousands of crashes every year by helping vehicles “talk” to each other.

vehicle to vehicle communication systems

“We are carrying the ball as far as we can to realize the potential of transportation technology to save lives,” said U.S. Transportation Secretary Anthony Foxx. “This long promised V2V rule is the next step in that progression.  Once deployed, V2V will provide 360-degree situational awareness on the road and will help us enhance vehicle safety.”

In February 2014, Secretary Foxx announced the Department would accelerate its work to enable V2V, directing the Department’s National Highway Traffic Safety Administration (NHTSA) to begin work on the rulemaking. NHTSA issued an Advance Notice of Proposed Rulemaking in August 2014. The advancement of the V2V rulemaking complements the Department’s work to accelerate the development and deployment of automated vehicles.

“Advanced vehicle technologies may well prove to be the silver bullet in saving lives on our roadways,” said NHTSA Administrator Mark Rosekind. “V2V and automated vehicle technologies each hold great potential to make our roads safer, and when combined, their potential is untold.”

The proposed rule announced today would require automakers to include V2V technologies in all new light-duty vehicles. The rule proposes requiring V2V devices to “speak the same language” through standardized messaging developed with industry.

Separately, the Department’s Federal Highway Administration plans to soon issue guidance for Vehicle-to-Infrastructure (V2I) communications, which will help transportation planners integrate the technologies to allow vehicles to “talk” to roadway infrastructure such as traffic lights, stop signs and work zones to improve mobility, reduce congestion and improve safety.

vehicle to vehicle communication systems

NHTSA estimates that safety applications enabled by V2V and V2I could eliminate or mitigate the severity of up to 80 percent of non-impaired crashes, including crashes at intersections or while changing lanes.

V2V devices would use the dedicated short range communications (DSRC) to transmit data, such as location, direction and speed, to nearby vehicles. That data would be updated and broadcast up to 10 times per second to nearby vehicles, and using that information, V2V-equipped vehicles can identify risks and provide warnings to drivers to avoid imminent crashes. Vehicles that contain automated driving functions—such as automatic emergency braking and adaptive cruise control—could also benefit from the use of V2V data to better avoid or reduce the consequences of crashes.

V2V communications can provide the vehicle and driver with enhanced abilities to address additional crash situations, including those, for example, in which a driver needs to decide if it is safe to pass on a two-lane road (potential head-on collision), make a left turn across the path of oncoming traffic, or determine if a vehicle approaching an intersection appears to be on a collision course. In those situations, V2V communications can detect developing threat situations hundreds of yards away, and often in situations in which the driver and on-board sensors alone cannot detect the threat.

Privacy is also protected in V2V safety transmissions. V2V technology does not involve the exchange of information linked to or, as a practical matter, linkable to an individual, and the rule would require extensive privacy and security controls in any V2V devices.

The notice of proposed rulemaking will be open for public comment for 90 days.

NHTSA 34-16
Tuesday, Dec. 13, 2016
Contact: Bryan Thomas, 202-366-9550, Public.Affairs@dot.gov

Additional resources:


vehicle to vehicle communication systems

WASHINGTON — U.S. auto safety regulators proposed requiring all new vehicles to be equipped with vehicle-to-vehicle communication systems, citing the technology’s significant potential to reduce crashes.

The proposed mandate, released by the Department of Transportation today, would require all new cars and light trucks to have dedicated short-range communication systems that transmit and receive basic messages about the vehicles’ speed, location, braking and other data. DSRC systems allow cars to “talk” to other vehicles on the road and to infrastructure equipped with the systems, allowing drivers to “see” around corners and be warned of potential crash.

“This technology has enormous safety potential to prevent hundreds of thousands of crashes and save lives,” Transportation Secretary Anthony Foxx said on a conference call with reporters.

Under the proposal, automakers would be required to equip half of all new cars with the technology two years after the National Highway Traffic Safety Administration issues a final rule. Full penetration would be required within four years after the rule is final.

U.S. officials have said the technology could potentially reduce non-impaired traffic crashes by 80 percent once fully deployed.

Regulators signaled their intent to mandate V2V systems in August of 2014. Under today’s proposal, the DSRC systems would be required to use a common set of communications protocols to ensure all vehicles “speak the same language,” the DOT said.

The proposal also contemplates the technology working alongside crash avoidance technologies like automatic emergency braking to help prevent collisions, Foxx said. The proposed rule also has privacy and security requirements, including 128-bit encryption on vehicle data transmissions, the department said.

In addition, the department said it plans to soon issue guidance on vehicle-to-infrastructure communications.


Saving lives

Last year, there were 6.3 million U.S. vehicle crashes. In October, NHTSA said U.S. traffic deaths jumped 10.4 percent in the first six months of 2016. The jump follows a spike in 2015, when road deaths rose 7.2 percent to 35,092, the highest full-year increase since 1966.

The rule would not require vehicles currently on U.S. roads to be retrofitted with the technology. Foxx said owners couldn’t turn off the technology but could turn off warnings.

The Alliance of Automobile Manufacturers, a trade group representing General Motors, Toyota Motor Corp., Volkswagen AG and other major automakers, noted the system is already being tested. The group said it would study the proposal.

Automakers are pushing to ensure that a portion of the spectrum reserved for connected vehicles is not used by other companies for other wireless device use. The U.S. Federal Communication Commission has begun testing potential sharing options.

Separately, the Federal Highway Administration plans to issue guidance for vehicle-to-infrastructure communications, which will help planners allow vehicles to “talk” to roadway infrastructure such as traffic lights.

Reuters contributed to this report.

vehicle to vehicle communication systems

The proposal is 400 pages long and is the culmination of a more than two-year development process, so there’s quite a lot of fleshing out there. Of course, rather than speculating, you could go read it — they accept public comment.


Let’s just concentrate on this for a moment. Aside from the fact it betrays a striking lack of knowledge about the backbone on which it would be built — what frequencies, where is the bandwidth, which particular services would you use or take this spectrum from, what is the technology (there’s much more to this than just announcing this has to be done and expecting it to be done, there are such things as technical standards), which is the spectrum controlling agency, FCC, NIAT ???) — It also betrays a tremendous expectation that things will work in specified ways. But radio-based systems, which this, of necessity would be, work in a manner you might not expect due to any number of factors, including antenna aperture, signal bounce, multipath distortion, phasing angles, adjacent band distortion and more. Then there are the smaller incidentals like performance in weather, how close is this to the spectrum of water itself (38 GHz) and so on.

Though I would expect there is much more to this proposal than meets the eye, at first blush, it is an ill-conceived, ill-thought out plan that needs far more fleshing out before it can honestly be considered anything other than a great trial balloon drop.


I looked at the RF or radio-frequency aspect of this particular public safety service. It is part of 75 MHz of spectrum authorized at 5.9 GHz.

The physical length of a radio wave at this particular region of spectrum is about 2.001 inches long. You can calculate this quite easily.

This spectrum is easily influenced by factors such as leaves blowing in the wind. Yes, a leaf can easily block this RF energy as can a piece of wood. Metal can easily block this wavelength.

Look at the structure of a vehicle. It isn’t made of many materials that don’t attenuate RF energy. The body of a vehicle is, by and large, metal, as is the drivetrain and suspension. Indeed, most of today’s vehicles are made of materials that block or attenuate radiofrequency energy.

Using this spectrum will necessitate the construction of special waveguides that allow vehicles to see one another. Given that this service will need general purpose or vertically polarization, for the most part, it is more than likely that each vehicle will need one or more waveguides.

If one waveguide is in the vicinity of another it is possible that there could be interaction and cancellation of a signal or signals. It is also possible, too, that there could be signal amplification

vehicle to vehicle communication systems