FMCSA Proposes to Amend Vehicle Safety Device Rule

FMCSA Proposes to Amend Vehicle Safety Device Rule

August 02, 2021
Share |

Key Points

  • The proposal would not impose new or more stringent requirements on drivers or motor carriers.
  • The proposal would not mandate the use of specific devices or technologies. Instead, the amendment would permit their voluntary use while mounted in a location that maximizes their effectiveness without impairing operational safety.

On July 6, 2021, the Federal Motor Carrier Safety Administration (FMCSA) proposed to increase the area that certain vehicle safety technology devices may be mounted on in commercial motor vehicle (CMV) windshields.

The FMCSA is requesting public comments on the proposed amendments. Comments are due on Aug. 5, 2021.

Vehicle Safety Technology Device Requirements

The original FMCSA regulations prohibit obstruction of the driver’s field of view by devices mounted at the top of the windshield. As a result, devices with vehicle safety technologies are required to be mounted:

  • Either not more than:
    • 100 millimeters (4 inches) below the upper edge of the area swept by the windshield wipers; or
    • 175 millimeters (7 inches) above the lower edge of the area swept by the windshield wipers; and
  • Outside the driver’s sightlines to the road and highway signs and signals.

Alternative Device Requirements

Under the proposal, FMCSA regulations would be modified to increase the mounting distance from 100 millimeters (4 inches) to 216 millimeters (8.5 inches) below the upper edge of the area swept by the windshield wipers.

The other parameters of the regulations will remain unchanged. The proposed amendments do not impose new or more stringent requirements on drivers or motor carriers; it simply codifies the temporary exemptions that have already been granted.


If the proposal is adopted, drivers can mount the vehicle safety technology in a location that is still effective and not an impairment to operational safety.

This Legal Update is not intended to be exhaustive nor should any discussion or opinions be construed as legal advice. Readers should contact legal counsel for legal advice. ©2021 Zywave, Inc. All rights reserved.

Attachments