The Federal Motor Carrier Safety Administration (FMCSA), joined by several trucking industry groups, is urging truck drivers and motor carriers to consider expanding their use of advanced driver assistance systems (ADAS).

FMCSA’s new “Tech-Celerate Now” program encourages carriers to adopt technologies such as:

  • Automatic emergency braking, air disc brakes, and adaptive cruise control systems;
  • Lane keeping assist, lane centering, and adaptive steering control;
  • Lane departure warning, forward collision warning, and blind spot warning; and
  • Driver-facing and road-facing cameras, and camera-based mirror systems.

Many of these ADAS technologies rely on cameras, sensors, antennas and communication devices. Manufacturers recommend mounting these devices inside the truck windshield for the best unobstructed view and data transmission. FMCSA seems to recognize that its own regulations on which devices can be fixed to the windshield and where to mount them can get in the way of the very technologies it promotes in the “Tech-Celerate Now” program.

So, the trucking regulator has issued a Notice of Proposed Rulemaking to address the mounting of safety technology devices.

Current FMCSA regulations prohibit the obstruction of the driver’s field of view by devices mounted at the top of the windshield. Antennas and similar devices must not be mounted more than six inches below the upper edge of the windshield, and must be outside the driver’s sight lines to the road and highway signs and signals.

However, those same regulations offer an exception for “vehicle safety technologies.” Vehicle safety technologies, under current law, must be mounted (1) not more than four inches below the upper edge of the area swept by the windshield wipers, or (2) not more than seven inches above the lower edge of the area swept by the windshield wipers, as well as outside the driver’s sight lines to the road and highway signs and signals.

Under the FMCSA proposal, the area in which carriers can mount vehicle safety technologies inside a truck windshield would expand from four inches to eight and a half inches below the upper edge of the area swept by the windshield wipers. The other parameters would not change. FMCSA points out that this expanded area for mounting vehicle safety technologies coincides with temporary exemptions already granted for similar devices. This proposal would legalize the expanded area for all vehicle safety technologies without need for an exemption.

FMCSA also wants to expand the definition of those devices. The existing definition speaks to “a fleet-related incident management system, performance or behavior management system, speed management system, forward collision warning or mitigation system, active cruise control system, and transponder.” FMCSA also proposes adding technologies that promote driver, occupant, and roadway safety to this list. This includes braking warning systems, braking assist systems, automatic emergency braking, driver camera system, attention assist warning, and traffic sign recognition – all elements of the “Tech-Celerate Now” program.

Comments on the proposed expanded mounting area and the expanded definition are due Aug. 5, 2021. To comment, go to and enter docket number FMCSA-2021-0037.