Search Interpretations

09-002149as df Maxon

Ms. Sherry Lafferty

Manager, Engineering

Maxon Lift Corp.

11921 Slauson Avenue

Sante Fe Springs, CA 90670-2221

Dear Ms. Lafferty:

This responds to your letter asking two questions regarding Federal Motor Vehicle Safety Standard No. 403, Platform lift systems for motor vehicles, and Standard No. 404, Platform lift installations in motor vehicles.

Your first question asks whether the area that is used for detecting occupancy while the lift is lower than the vehicle floor bed should include 18 inches of the floor area. As explained below, our answer is yes. Your second question asks about the responsibility of a lift manufacturer to provide instructions in the installation manual to ensure that a vehicle manufacturer installs the lift in such a way as to detect the entire 18-inch area.

By way of background, the National Highway Traffic Safety Administration (NHTSA) is authorized to issue Federal motor vehicle safety standards (FMVSSs) that set performance requirements for new motor vehicles and items of motor vehicle equipment (see 49 U.S.C. Chapter 301). NHTSA does not provide approvals of motor vehicles or motor vehicle equipment.  Instead, manufacturers are required to self-certify that their products conform to all applicable safety standards that are in effect on the date of manufacture. NHTSA selects a sampling of new vehicles and equipment each year to determine their compliance with applicable FMVSSs.  If our testing or examination reveals an apparent noncompliance, we may require the manufacturer to remedy the noncompliance, and may initiate an enforcement proceeding if necessary to ensure that the manufacturer takes appropriate action. NHTSA also investigates safety-related defects.

Extent of Platform Threshold Area

Your first question asks whether under the definition of the platform threshold area in FMVSS No. 403, the area that is used for detecting occupancy while the lift is lower than the vehicle floor bed should include 18 inches of the bus floor area.

Platform threshold area is defined in the standard (S4) as:

The rectangular area of the vehicle floor defined by moving a line that lies on the portion of the edge of the vehicle floor directly adjacent to the platform through a distance of 457 mm (18 inches) across the vehicle floor in a direction perpendicular to the edge. Any portion of a bridging device that lies on this area must be considered part of that area.

The platform threshold area is also illustrated graphically as the shaded area in Figure 2 of the standard.

As indicated by the above definition of platform threshold area and by Figure 2, the platform threshold area encompasses parts of the vehicles floor. Further, as you indicate in your letter, the platform threshold area is relevant for determining the area in which detection of an occupant must occur when the lift is lower than the vehicle floor bed. S6.1.2 and S6.1.3 require that an alarm activate when a passenger or mobility aid is on the platform threshold area, and the lift is more than 1 inch below it. Thus, the platform threshold area encompasses the 18 inches of bus floor area across the vehicle floor.

Installation Instructions

Your second question asks whether, if a lift sensing mechanism does not physically cover the platform threshold area, a lift manufacturer must provide instructions that ensure a vehicle manufacturer install the lift in such a way as to detect the entire 18-inch area. Our answer is yes.

The responsibilities of the lift manufacturer, with regard to installation instructions, are set forth in S6.13 of FMVSS No. 403. S6.13.2 requires lift manufacturers to provide installation instructions with each lift, including procedures for operational checks that the vehicle manufacturer must perform to verify that the lift is fully operational. Such checks include, but are not limited to, the threshold-warning signal. Id. It is the responsibility of the lift manufacturer to provide a lift that, when installed according to manufacturer instructions, complies with all the applicable requirements of FMVSS

No. 403.

Furthermore, under S4.1.3 of FMVSS No. 404, Platform Lift Installations in Motor Vehicles, it is the responsibility of the vehicle manufacturer to install an FMVSS

No. 403-compliant platform lift according to the instructions provided by the platform lift

manufacturer. Under S4.1.4 of FMVSS No. 404, the platform lift, as installed, must continue to comply with all applicable requirements of FMVSS No. 403. Therefore, the lift manufacturer would have to provide instructions on how to properly install a lift that meets FMVSS No. 403s threshold warning signal requirement of S6.1.

If you have any further questions, please contact my office at (202) 366-2992.


O. Kevin Vincent

Chief Counsel