Western Star Trucks
2076 Enterprise Way
Kelowna, British Columbia
CANADA V1Y 6H8
Dear Mr. Moore:
This responds to your request for an interpretation whether a truck's "vernier hand throttle" (VHT) that is not used in driving the vehicle, must meet the "hand operated control" requirements of Standard No. 101 Controls and displays. As explained below, the answer is no.
In your letter, you stated that the VHT is used in trucks to power vocational applications, such as dump trucks or cement mixers that power a hydraulic pump, providing energy to a hydraulic motor or ram. The VHT is used only when the vehicle is stationary or moving at a very low speed. You further wrote that the people using the VHT are usually professionals, who perform these tasks daily.
You further wrote that the VHT is placed under the steering column. When in the normal seated position, the driver cannot see the VHT, but can operate it with difficulty. You explained that in its location, the VHT can be operated either from the ground where the operator can easily monitor the auxiliary equipment powered by the VHT, or from the driver's seat. The VHT is placed out of the way of the driver's knees, where it may interfere with driving controls.
Your letter concluded that if NHTSA determines the VHT to be a "hand throttle" as defined in Standard No. 101, your company would have difficulty meeting Standard No. 101 by placing a label in a meaningful location where the driver can both see the label, and have the label be adjacent to the VHT. You further stated your belief that identifying the VHT as a "throttle" may imply that the VHT is meant to regulate road speed while driving, which the VHT does not do.
Standard No. 101's purpose, stated at S2, makes clear the Standard is intended to apply to controls and displays used in the driving task:
The purpose of the standard is to ensure the accessibility and visibility of motor vehicle controls and displays and to facilitate their selection under daylight and nighttime conditions, in order to reduce the safety hazards caused by the diversion of the driver's attention from the driving task, and by mistakes in selecting controls.
You have explained how the VHT, although called a "throttle," is not the same as a throttle used to regulate road speed while driving. Since it is not a control used in the driving task, and is not a "hand throttle" specified in S5.1 Location, the VHT need not meet Standard No. 101.
I hope this information is helpful. If you have any other questions, please contact Dorothy Nakama of my staff at this address or by telephone at (202) 366-2992.
Acting Chief Counsel