The Vehicle Sound for Pedestrians Subcommittee of the SAE Safety and Human Factors Committee is developing a test procedure to determine the sound output of electric and hybrid-electric powertrain vehicles at certain low-speed conditions. Establishing a consistent method of measuring the sound output of these vehicles will facilitate further study into the need for additional measures to alert pedestrians to the presence of these vehicles in traffic. This test procedure could also become industry practice should it later be deemed necessary to record the sound output of certain vehicles in low speed traffic conditions where vehicles, pedestrians and other road users are co-mingled.
The Vehicle Sound for Pedestrians subcommittee to the SAE Safety & Human Factors Committee is in the process of developing a method of repeatedly and consistently measuring the sound level output of electric and hybrid-electric powertrain vehicles at low speeds. The interest in developing a method of measuring the sound output of these types of vehicles at low speed relates to a concern brought forth by members of the blind community related to the relative difficulty blind pedestrians have recognizing vehicles with less sound output in traffic. The difficulty in identifying these vehicles has lead to concerns among the blind community that they are at greater risk of involvement in a pedestrian crash if they are unaware of the presence of a vehicle that may be moving and cross paths with that vehicle. It is the intention of the Vehicle Sound for Pedestrians subcommittee to draft a document, perhaps in the form of an information report that describes this issue in detail. This base document would also explain the history and chronology of this issue, along with efforts to study and understand any available cause-and-effect information, statistical analysis of this issue from crash databases and other relevant efforts. In the process of studying this issue it was determined by this subcommittee that it would become necessary to establish a consistent method of determining the sound output level of the vehicles in question. The rationale or base document description of this issue will outline the reasons to limit this issue to electric and hybrid electric powertrain vehicles as well as other relevant information. Our specific request is to establish a "J" number for the base (rationale) document to be drafted at a later date report. That same J number would be used as the basis for the name of this recommended practice, ie: J XXXX-1. This structure would facilitate the addition of future measurement and assessment methods for other technical measures to address this concern, including non-sound based approaches.