Federal Motor Vehicle Safety Standards V2V Communications; Withdrawal

Federal Motor Vehicle Safety Standards; V2V Communications

Dates

NHTSA is withdrawing the proposed rule published January 12, 2017 (82 FR 3854) as of November 20, 2023.

Supplementary Information

Background on V2V Technology

Vehicle-to-vehicle (V2V) technology consists of systems that enable vehicles to broadcast Basic Safety Messages (BSMs) about their speed, heading, brake status, and other vehicle information using the radiofrequency spectrum, and to receive the same information from surrounding vehicles also equipped with the technology. When received in a timely manner, this information could help vehicle systems identify potential crash situations with other vehicles and provide warning messages to their drivers. V2V technology is distinct from "vehicle-resident" technologies ( e.g., camera and sensor-based systems) and would operate separately from, or complementarily to, advanced driver assistance systems. V2V employs signals which can be received around corners or other physical obstructions and in suboptimal weather and light conditions, without line-of-sight limitations that vehicle-resident technologies can face.

Summary of the Notice of Proposed Rulemaking

On January 12, 2017, the agency published a notice of proposed rulemaking (NPRM) to create a new Federal Motor Vehicle Safety Standard (FMVSS) for V2V communications, which NHTSA proposed to designate as FMVSS No. 150. ⁽¹⁾ The NPRM proposed to mandate V2V communication technology in all new light vehicles based on DSRC radiofrequency transmissions, ⁽²⁾ and also proposed a pathway for vehicles to comply using non-DSRC technology if certain performance and interoperability standards were met. The NPRM further proposed technical requirements for the content, security, and handling of V2V messages as well as system requirements more broadly. While the NPRM proposed to allow compliance using non-DSRC technologies, all of the technical requirements (and expectations about the effectiveness of V2V communications at helping vehicles to prevent crashes) were based on DSRC, and the proposal would have required non-DSRC technologies to be interoperable with DSRC.

The NPRM also discussed the possibility that the 5.9 gigahertz (GHz) band of radiofrequency spectrum in which DSRC has operated might be modified and/or opened to unlicensed devices, such as cordless telephones and outdoor broadband transceivers. ⁽³⁾ NHTSA sought comment on what that might mean for the effectiveness or viability of V2V systems using DSRC technology.

Summary of Comments

NHTSA received 492 comments regarding the 2017 NPRM. ⁽⁴⁾ More than 100 comments were submitted by organizations including, but not limited to: automotive manufacturers, suppliers and associations, and wireless companies and associations. There were also comments from consumer and trade associations, nonprofits, think tanks, and Federal, State, and local governments, and more than 350 comments were received from individual citizens. Most organizations expressed broad support for mandating V2V technology on all new light vehicles and had various comments about the technical implementation thereof. Most individual citizens who commented expressed concerns about cybersecurity, privacy, and electromagnetic hypersensitivity, though some supported a V2V mandate for its potential safety benefits.

Commenters also addressed the FCC proposals to allow sharing of the 5.9 GHz radio frequency band. Approximately 20 automotive organizations addressed these proposals. The general consensus among commenters was that the specific V2V mandate proposed in the NPRM would need to be revisited should there be changes to the regulations governing the use of the 5.9 GHz band.

New Technologies

Since the release of the NPRM, one potential alternative for DSRC, LTE  ⁽⁵⁾ Cellular-V2X, or LTE C-V2X, has emerged and is supported by some industry stakeholders as an alternative to DSRC. While based on cellular technology, LTE C-V2X offers device-to-device communications without the need for a cell tower to schedule and relay messages. Standards organizations that helped develop 5G cellular technology are also working on a 5G-based version of C-V2X (5G C-V2X) that will focus on device-to-device communications with the potential for enhanced performance over either DSRC or LTE C-V2X, and potentially allow for further advancements in vehicle platooning, advanced driving, extended sensors, and remote driving.

Revisions to the 5.9 GHz Regulations

On November 18, 2020, the FCC issued a final rule which approved a reallocation of the 5.9 GHz spectrum  ⁽⁶⁾ that reassigns the lower 45 MHz of the previously reserved spectrum for unlicensed use. It further requires that 20 MHz of the 30 MHz remaining for transportation use transition from DSRC to cellular vehicle-to-everything (C-V2X) technology. Of note, on April 24, 2023, the FCC granted a joint waiver allowing deployment of C-V2X technology. ⁽⁷⁾ The U.S. Department of Transportation, in cooperation with the NTIA, DoD, NASA and NSF, conducted a data-driven technical analysis to inform the FCC with the relevant information to make a determination on the technical parameters requested in the waiver. The FCC's April 24 action allows proponents of C-V2X use of the upper 30 MHz of the 5.9 GHz band for deployment. DOT has ongoing, active research in the area of whether and how C-V2X could support safety-critical technologies. ⁽⁸⁾

Rationale for Withdrawal

NHTSA and the DOT believe that V2V and other vehicle-to-everything (V2X) technologies hold tremendous promise to improve safety and to offer innovative services to consumers. The record in response to the NPRM supports this conclusion.

However, given the advent of new V2V communications protocol, and the revised regulations governing the 5.9 GHz band, the agency believes a regulatory action to revise the proposed rulemaking cannot be reasonably accomplished at this time. For this reason, the agency has decided to withdraw the V2V rule at this time.

Conclusion

NHTSA does not believe it is reasonable to move forward with the proposal. Based on its evaluation of the available information, NHTSA has concluded that significant analysis must be conducted before determining whether a V2V standard is appropriate, and, if so, what that standard would encompass. Accordingly, NHTSA withdraws the NPRM. NHTSA will continue to monitor the development of V2V technology for possible future vehicle safety applications. The NPRM published in the Federal Register January 12, 2017, at 82 FR 3854, is withdrawn.

⁽¹⁾  82 FR 3854.

⁽²⁾  DSRC is a short-range wireless technology that would provide local, nearly instantaneous message transmission with good reliability, critical characteristics for detecting potential and imminent crash scenarios.

⁽³⁾  Detailed in a Public Notice from the FCC: https://apps.fcc.gov/edocs_public/attachmatch/FCC-16-68A1_Rcd.pdf.

⁽⁴⁾  Comments are available in Docket No. NHTSA-2016-0126 at http://www.regulations.gov.

⁽⁵⁾  LTE, Long-Term Evolution, is a predecessor to 3G cellular technology and a precursor to 4G cellular technology.

⁽⁶⁾  Detailed in a First Report and Order, Further Notice of Proposed Rulemaking, and Order of Proposed Modification, document FCC-CIRC2011-01, which can be found at https://docs.fcc.gov/public/attachments/DOC-367827A1.pdf.

⁽⁷⁾ https://docs.fcc.gov/public/attachments/DA-23-343A1.pdf.

⁽⁸⁾ See, e.g., https://www.transportation.gov/content/safety-band (last accessed Aug. 22, 2023).