Interpretation ID: aiam4893
P. Eng. Senior Compliance Engineer Compliance Engineering and Vehicle Testing Road Safety and Motor Vehicle Regulation Directorate Transport Canada (ASFAAA) Ottawa
Ontario CANADA K1A ON5;
Dear Mr. Farr: This responds to your letter of June 19, 1991 requesting information regarding the method used to calculate the angle specified in section S4.3.1.1 of Standard No. 210. Your first question asks whether the agency uses a three dimensional protocol or a two dimensional protocol when calculating the angle formed by the line from the seating reference point to the nearest contact point of the belt with the hardware attaching it to the anchorage. NHTSA uses a two dimensional protocol for these purposes. The agency recognizes that, as stated in your letter, this does not take into account the transverse coordinate of these two points. However, the agency does not believe that use of a two dimensional protocol diminishes the safety benefits offered by the safety belt system. Your second question asks whether the agency has made any interpretations of the phrase 'the nearest contact point of the belt with the hardware connecting it to the anchorage.' The agency has never made a generally applicable interpretation of this phrase. When manufacturers have requested an interpretation for a specific design, the agency has indicated which point we would consider 'the nearest contact point.' If you have a specific design that concerns you, we can make a similar interpretation if you send us a diagram. It is always a pleasure to hear from representatives of Transport Canada. We believe our cooperation has been mutually beneficial for many years. If you have further questions or need some additional information in this area, please contact Mary Versailles of my staff at this address or by telephone at (202) 366-2992. Sincerely, Paul Jackson Rice Chief Counsel;