United States Department of TransportationInterpretation ID: 12566-3.pja
Project Engineer
PIVCO AS
Stanseveien 4
N-0975 Oslo, Norway
Dear Mr. Breiland:
This responds to your letter of September 27, 1996, asking several questions about how the Federal Motor Vehicle Safety Standards, especially Standard No. 102, Transmission Shift Lever Sequence, Starter Interlock, and Transmission Braking Effect, would apply to the electric vehicle (EV) you produce. The vehicle has only one forward gear and a regenerative braking system, and weighs less than 4,536 kg. Our response follows your letter's organization in which you group questions into four categories: regeneration, symbols and displays, reverse, and transmission shift lever sequence.
You first ask whether regeneration would "violate[s] any regulations." Regeneration, or use of the engine as a generator to slow the vehicle and recharge the battery, does not violate any National Highway Traffic Safety Administration (NHTSA) regulation, and Standard No. 102 does not require the regeneration system you described. The vehicle you described has only one forward speed, so the requirement for transmission braking effect in S3.1.2 of Standard No. 102 does not apply. As we indicated in our May 3, 1996 interpretation letter to you, the applicability of this requirement is restricted by the prefatory phrase "[i]n vehicles having more than one forward transmission gear ratio . . . ."
NHTSA does not have any recommendations on how regeneration should be performed or on the need for a switch to disable regeneration. Whether to equip a vehicle with these characteristics is at the manufacturer's option. However, as you are aware, NHTSA has proposed to include the regenerative braking effect in the performance of the service brakes under Standard No. 135, Passenger Car Brake Systems, only if the regenerative braking effect is actuated by the service brakes
(60 FR 49544, copy enclosed). We would consider a vehicle equipped with a disabling switch as not having the regenerative system actuated by the service brakes, since regeneration could be disabled. Therefore, if the final rule is issued as proposed, you would not be able to use regeneration in your braking performance tests.
You also raised several questions about Standard No. 101, Controls and Displays. There is no standardization of controls, displays, and symbols unique to EVs, and no special telltales that are required for EVs. Provision of a power or current gauge is at your option. NHTSA does not regulate use of the additional EV-related telltales mentioned in your letter, and you may provide them at your option, so long as they do not result in confusion with the required telltales. A complete response to your question "how should we proceed to ensure that illumination of telltales fulfills Standard No. 101" would merely be a recitation of S5.3.4 (not S5.3.3, as cited in your letter) that specifies requirements for illumination of telltales.
NHTSA has no recommended maximum reverse speed. However, most vehicle reverse speeds are the lowest of any gear. This is appropriate, because visibility is limited by the necessity to turn around, and drivers are less accustomed to steering in reverse. Therefore, an unreasonable increase in reverse gear speed could result in a safety problem. There are no requirements for driver "warning" signals when the shift lever is in reverse, other than the requirement in S3.1.4 of Standard No. 102 to display the shift lever position.
You stated that you were unsure of which regulations exist concerning the relationship between the ignition key, shift lever sequence, and the "park lock device" on EVs. There are no special requirements in these areas that pertain only to EVs. The regulations concerning the relationship of the "park lock device" to the shift position in automatic transmission vehicles are in S4.2.1(a) of Standard No. 114, Theft Protection. Basically, they require that the key cannot be removed unless the vehicle is in the park position, and that the vehicle prevent mobility when the vehicle is in park. There is no regulatory problem with your ignition key positions (Off, Radio, On, Start). You proposed three transmission shift lever sequences and asked us to tell you if any of the proposals comply with our regulations. Note that the first sentence of S3.1.1 of Standard No. 102 requires "[a] neutral position shall be located between forward drive and reverse drive positions." Therefore your proposal A (P-R-N-D) complies with this requirement, while proposal B (P-R-D) and proposal C (R-D) do not comply. Note, however, that S4.3 prohibits the park-lock device from taking effect when the vehicle is in motion, as your description of proposal A seems to suggest.
Regarding your uncertainty on which office to send your inquiries to, it depends on the type of question you have. You should send all requests for interpretation of our standards to this office. Requests for standards or other technical information should be directed to the Office of Safety Performance Standards (that office's designation has been changed from NRM, as mentioned in your letter, to NPS). We advise against directing the letter to any particular person within the office, given reorganizations and personnel changes.
If you have any further questions, please feel free to contact Paul Atelsek of my staff at this address or by telephone at (202) 366-2992.
Sincerely,
John Womack
Acting Chief Counsel
Enclosure
ref:102#101#135#114
d.12/17/96