FMCSA weighs lighting exemptions | Huge Ford Super Duty recall

The Federal Motor Carrier Safety Administration reopened the comment period for an exemption request from Grote Industries to allow motor carriers to operate CMVs equipped with auxiliary warning lamps controlled by Grote's Rear-End Collision Warning (RCW) system.

FMCSA previously accepted comments on the request in February, but Grote provided additional information on the design and operation of the RCW system, including the color and activation sequence of the auxiliary warning lamps, the interaction between the RCW and brake-activated functionality, system operation on combination vehicles, and the operation of the radar detection system.

As originally reported, Grote’s RCW system uses rear-facing, long-range radar to calculate time-to-collision (TTC) for vehicles approaching from behind and activates auxiliary warning lamps when a collision risk threshold is reached. The system activates a signal circuit when the TTC is less than or equal to a specific safety threshold -- typically between 2.1 and 4.0 seconds -- representing the average time required for a driver and vehicle to react to a hazard.

In documents provided to FMCSA upon request, Grote clarified that when operating as part of the RCW system, the auxiliary warning lamps pulse in amber for up to four seconds with each activation of the RCW signal circuit and do not transition to a steady-burning red indication. Grote explained that the transition from amber pulsation to steady-burning red is associated with the brake-activated auxiliary pulsating lamp function, not the RCW warning function.

This story was originally published by Overdrive. Read the full story at Overdrive →