NHTSA Issues an NPRM to allow more Flexibility in the Pedestrian Alert Sounds of Hybrid and Electric Vehicles (HEVs)
The National Highway Traffic Safety Administration (NHTSA) published a Notice of Proposed Rulemaking (NPRM) in the September 17, 2019 Federal Register (FR Vol. 84 No.180; Docket No. NHTSA-2019-0085). This NPRM suggests that the HEVs (Quiet Vehicles) have the limitation of having only one sound per vehicle model from the FMVSS requirements, allowing manufacturers to install many variations of the alert in a vehicle type.
NHTSA originally promulgated FMVSS No. 141 pursuant to the Pedestrian Safety Enhancement Act (PSEA) of 2010. PSEA mandated that NHTSA must establish a new motor vehicle safety standard applying to HEVs and PSEA stated the new standard must establish performance requirements for an alert sound that allows blind and other pedestrians to reasonably detect a nearby electric or hybrid vehicle operating below the cross-over speed.
Currently, the HEV pedestrian alert sounds are allowed to vary with vehicle operating condition (stationary, reverse, 10km/h, 20km/h, and 30km/h), but only one sound per operating condition is allowed for all vehicles of the same model, model year, body type and trim level. NHTSA is requesting comments on whether there should be a limit to the number of compliant sounds, and if so, what should the limit be.
This NPRM responds to a Petition for Reconsideration of the FMVSS No. 141 Final Rule (FR) published December 14, 2016. In a joint petition, the Alliance of Automobile Manufacturers (Alliance) and Global Automakers (Global), the two main automotive industry groups in the U.S. representing most light vehicle manufacturers, requested several amendments.
One of the requested amendments was that NHTSA modify FMVSS No. 141 so that each HEV can be equipped with a suite of several pedestrian alert sounds for the driver to choose from rather than one sound. According to the petitioners, providing this choice is important for consumer acceptance of future HEVs that will have pedestrian alert sounds in compliance with FMVSS No. 141.
Alliance/Global submitted a follow-up letter dated March 1, 2017, to supplement their petition. They indicated that although the variety of alert sounds that manufacturers can create which comply with FMVSS 114 are virtually unlimited due to the acoustic flexibility provided by the requirements, if NHTSA amended FMVSS No. 141 to allow selectable sounds, they recommend a limit of five sounds per vehicle.
They provided the following rationale: Because every additional driver-selectable choice of sound requires a separate certification test and a separate compliance test, the number of driver-selectable choices provided by manufacturers would naturally be limited for practical reasons. However, to address potential concerns that manufacturers might provide too many optional sounds, NHTSA recommends that the number of permitted driver-selectable sounds be limited to no more than five driver-selectable alert sounds for any make, model, trim level, model year vehicle.
After considering the Alliance/Global petition, and recognizing that the language of PSEA regarding sameness of sounds among vehicles of the same make and model is subject to more than one interpretation, and also that consumer preferences for vehicle alert sounds will depend on subjective factors, NHTSA has decided to propose amending FMVSS No. 141 to allow an unlimited number of pedestrian alert sounds per vehicle for any operating condition.
This proposal would also improve international harmonization by aligning FMVSS No. 141 more closely with international regulations, particularly United Nations ECE Regulation No. 138 for Audible Vehicle Alerting Systems, which states "a vehicle manufacturer may define alternative sounds which can be selected by the driver."
The ECE regulation does not specify a particular limit on the number of alternative sounds that may be provided. This NPRM also makes a technical change to Section S6.7 of FMVSS No. 141 relating to ambient noise correction procedures, as well as correcting two dates in the FMVSS No. 141 phase-in reporting requirements in 49 CFR 585, Subpart N.
NHTSA indicates that the proposed rule is deregulatory in nature and is expected to generate benefits and cost savings in excess of costs. The proposed rule provides manufacturers with more flexibility and options in developing and installing sounds for their hybrid and electric vehicles.
Comments on the NPRM must be submitted by November 1, 2019.