Interpretation ID: nht88-3.60

TYPE: INTERPRETATION-NHTSA

DATE: 10/03/88 EST

FROM: ERIKA Z. JONES -- NHTSA CHIEF COUNSEL

TO: KUNIO SHIMAZU -- GENERAL MANAGER, U.S. OFFICE - TOYOTA

TITLE: NONE

ATTACHMT: FEBRUARY 26, 1988 LETTER FROM SHIMAZU TO JONES

TEXT: This responds to your letter seeking an interpretation of Standard No. 208, Occupant Crash Protection (49 CFR @ 571.208). I apologize for the delay in this response. Specifically, you were concerned with the requirements for positioning automatic safet y belts on the test dummy prior to dynamic testing. You noted that, before conducting compliance testing of vehicles with automatic belt systems, section S10.5.2 of Standard No. 208 necessitates the following step: "Ensure that the upper torso belt lies flat on the test dummy's shoulder after the automatic belt has been placed on the test dummy." You asserted that this section does not clearly specify the belt path or how the belt is to be positioned on the dummy's shoulder. You further expressed your concern that, during the agency compliance testing, test personnel might believe that they are prohibited from adjusting the belt path on the dummy after the door has been shut for any reason other than the belt's failure to lie flat on the test dummy's shoulder. You asserted that, if NHTSA does not adjust the belt path as you have suggested for its compliance testing of vehicles with automatic belts, the compliance testing will be insufficiently representative of "real-world" performance of the automa tic belts.

Standard No. 208 does provide for adjustment of automatic belts only if the belt fails to lie flat on the test dummy's shoulder. Belt systems that require some additional deliberate actions by the vehicle occupant to provide effective crash protection f or the occupant are not automatic belt systems within the meaning of Standard No. 208, as explained below.

Standard No. 208 has always permitted manufacturers to comply with its requirement for automatic crash protection by any means that "requires no action by vehicle occupants." See 35 FR 14941; September 25, 1970. Automatic safety belts that require no ac tion by vehicle occupants are one means of satisfying the requirement for automatic crash protection. On April 25, 1974 (39 FR 14593), the agency issued an interpretation of this concept, in which the agency said that it would not consider a belt

system that had to be manually moved out of the way by the occupant to be an "automatic" system within the meaning of Standard No. 208. The following discussion also appeared, at 39 FR 14594:

The question of what constitutes "no action by vehicle occupants" in a vehicle equipped with (presumptively) passive belts is best considered in two stages: (1) Entry and exit from the vehicle, and (2) positioning of the belt for safety and comfort.

* * *

The second question relates to the usefulness of the system once the occupant has been seated. The essence of a passive system is that it provides at least the minimum level of protection without relying on occupant action to deploy the restraint. A t this stage, then, the question is whether an occupant who has seated himself without taking any "additional action" is in fact protected in a 30 mph impact. This can be measured by conducting the impact tests with the belt positioned on the test dummy in the orientation that results when a human occupant enters the vehicle according to the first test described above. It would not be required that the belt position itself for maximum comfort of the human occupant, if it met the safety requirements. For example, if the belt were to fall across the upper arm instead of the clavicle, but still passed the test, the system would be considered conforming.

After further consideration, the agency tentatively concluded that its interpretation might have been too stringent in suggesting that a belt system that had to be manually moved out of the way by an occupant to enter or exit the vehicle would not be con sidered an automatic belt system for purposes of Standard No. 208. The agency sought public comment on this tentative conclusion in an April 12, 1985 notice (50 FR 14580). The four commenters that responded to this request all concurred with the agency 's judgment that the 1974 interpretation was too stringent, and the agency revised its interpretation in a November 6, 1985 rule (50 FR 46056). The following discussion appears at 50 FR 46064:

. . . The concept of an occupant protection system which requires "no action by vehicle occupants," as that term is used in Standard No. 208, is intended to designate a system which will perform its protective restraining function after a normal proce ss of ingress or egress without separate deliberate actions by the vehicle occupants to deploy the restraint system. Thus, the agency considers an occupant protection system to be automatic if an occupant has to take no action to deploy the system but w ould normally slightly push the safety belt webbing aside when entering or exiting the vehicle or would normally make a slight adjustment in the webbing for comfort. . . . (Emphasis in original)

This interpretation was added to the end of Standard No. 208 to make clear that a belt system requires "no action by vehicle occupants" if the occupant must slightly push the webbing when entering or exiting the vehicle or if the occupant must make a sli ght adjustment to improve comfort. This interpretation neither said nor implied that a belt system

that must be adjusted to provide effective occupant protection would be considered an automatic belt system for the purposes of Standard No. 208. Indeed, since the vehicle occupant would have to take separate deliberate actions to deploy such a belt syst em, the interpretation makes clear that such a system would not be considered an automatic belt system.

The positioning procedures for automatic belts reflect this understanding of what constitutes an "automatic" belt system. Such procedures were added to Standard No. 208 in a September 5, 1986 final rule (51 FR 31765). The following discussion appeared in the preamble to that rule: In the agency's NCAP testing, the only adjustment NHTSA has made to an automatic belt once it has been deployed on the test dummy is to ensure that the belt is lying flat on the test dummy's shoulder when the belt is in its final position. The agency is adopting the same procedure for the Standard No. 208 compliance test. 51 FR 31766.

An adjustment to ensure that the belt webbing is not twisted on the test dummy's shoulder is the sort of adjustment that would normally be made by a vehicle occupant for comfort. Hence, this type of adjustment in compliance testing is consistent with th e November 6, 1985 interpretation of automatic belt systems for the purposes of Standard No. 208.

NHTSA intentionally did not provide for any further adjustments of automatic belts prior to Standard No. 208 compliance testing, because automatic belts require no action by vehicle occupants. Any belt systems that need some further adjustments to offer effective occupant protection require some action by vehicle occupants, and therefore are not automatic belt systems for the purposes of Standard No. 208.