Interpretation ID: nht90-4.96

TYPE: Interpretation-NHTSA

DATE: December 26, 1990

FROM: Paul Jackson Rice -- Chief Counsel, NHTSA

TO: Captain J.P. Henries -- Safety Officer, Virginia State Police

TITLE: None

ATTACHMT: Attached to letter dated 11-6-90 from J.P. Henries to P.J. Rice (OCC 5411)

TEXT:

This responds to your recent letter seeking further information about the Federal motor vehicle safety standards, and the extent to which those standards require safety belts to include a lap belt portion. More specifically, you stated that Virginia's S tate Inspection Program currently requires any 1963 and subsequent model years vehicles designed and licensed primarily for passenger use to be equipped with lap belts or lap/shoulder belts for at least two front seating positions. However, my September 10, 1990 letter to Mr. Rembert Ryals explained that front seating positions equipped with automatic safety belts that are certified as complying with our 30 mph frontal crash protection requirements are not required to include a lap belt either as a par t of the automatic belt system or as a separate manual lap belt. To aid in the efficient administration of Virginia's State Inspection Program, you asked how Virginia safety inspectors could readily identify those vehicles that were not originally requi red to be equipped with lap belts. I am pleased to have this opportunity to provide you with the following information.

Standard No. 208, Occupant Crash Protection (49 CFR S571.208), requires every vehicle other than a bus to have, as original equipment, a safety belt installed at every "designated seating position." Two different types of safety belts have been installe d pursuant to this requirement. The first type of safety belt is generally called a "manual" safety belt. With manual safety belts, the occupant of the seat must take some action to fasten the belt to be protected in a crash. Manual belts are required t o have a lap belt portion, that is, manual safety belts must be either lap-only or lap/shoulder safety belts.

The second and newer type of safety belt is called an "automatic" safety belt. An automatic safety belt positions itself to protect an occupant of the seat without any separate deliberate actions by the occupant. The occupant protection afforded by aut omatic safety belts is evaluated in a 30 mph crash test of the vehicle using test dummies as surrogates for human occupants. Because automatic safety belts must demonstrate their effectiveness in a crash test, they are not subject to all of the requirem ents that apply to manual safety belts. One of the manual belt requirements that does not apply to automatic belts is the requirement that the safety belt include a lap belt portion. Hence, as noted in my letter to Mr. Ryals, automatic belts are not re quired to include a lap belt.

It is easy to distinguish automatic safety belts from manual safety belts, by looking at where the upper end of the shoulder belt is anchored to the vehicle. Manual belts have the upper end of the shoulder belt anchored to the vehicle structure, such as the B-pillars. Again, since most current

safety belts are manual belts, this is the safety belt anchorage location with which you and the members of your department are most familiar. Because automatic belts must position themselves around occupants automatically, they must be anchored in a dif ferent way. Nonmotorized automatic belts are anchored to the door itself, while motorized automatic belts run along a track over the top of the doorframe. These anchorage locations enable either design of the automatic belt to properly position itself around a seat's occupant when the person gets into the vehicle and closes the door, and enable the automatic belt to move out of the way to allow the person to get out of the vehicle when the door is opened.

Although automatic belts are not required to include a lap belt, nearly all manufacturers have voluntarily chosen to provide lap belts for seating positions equipped with automatic belts, either as part of the automatic belt or as a separate manual belt. This is not always the case, however, as Volkswagen, for instance, has not voluntarily chosen to provide a lap belt with some of its automatic belts. Further, since there is no requirement to provide those lap belts, manufacturers may not choose to co ntinue providing lap belts in the future for seating positions equipped with automatic belts.

I hope this information is helpful. Please let me know if you have any further questions or need some additional information on this subject.