Obviously there are number of differences between alternative fuel vehicles and cars with traditional internal combustion engines. However, there are also a number less obvious differences too. For example, hybrid and EV engines make a lot less noise than internal combustion engines. While those who live near busy streets might consider this a good thing, especially in the evening hours, the near silence of engines powered by alternative fuels definitely has some drawbacks. One of the biggest drawbacks for a lot of automotive enthusiasts is that when driving a hybrid or EV, they aren’t treated to the powerful engine noise that they expect when accelerating or revving the engine. Further, on a more serious note, the National Highway Traffic Safety Administration (NHTSA) fears that quieter engines pose a very real danger to pedestrians—especially those with impaired vision.
According to an Auto Blog report, in the interest of better protecting pedestrians, the NHTSA finally came out with guidelines for hybrids and EVs regarding when they must make noise and how much noise they must make. If you’re interested, you can take a look at the guidelines here in this large PDF. Alternatively, you can click on the previous link to see a copy of the press release announcing the NHTSA’s proposed guidelines as published by Auto Blog.
The NHTSA was initially asked to propose minimum sound guidelines for hybrids and EVs back in 2010 when the Pedestrian Safety Enhancement Act was passed by Congress, but they did not release the proposal—Federal Motor Vehicle Safety Standard No. 141—until just this week. If implemented, the standard is expected to prevent approximately 2,800 pedestrian injuries and 35 pedestrian deaths each year. The proposed standard will require hybrids and EVs to emit a noise “detectable under a wide range of street noises and other ambient background sounds when the vehicle is traveling under 18 miles an hour.” Though the NHTSA will allow automakers to choose the specific sounds their vehicles will make, under the proposed guidelines, all vehicles of the same make and model will be required to utilize the same sounds.
The NHTSA expects that because most EVs already have the sort of technology required to produce the proposed sounds, the cost required to comply with the guidelines will be felt most acutely by automakers who manufacture hybrid vehicles. For those automakers, Auto Blog reports that it will cost approximately $30 to incorporate the noise making technology in each vehicle. The public can express their opinions on the proposed guidelines for the next 60 days. In the press release, the NHTSA did not include the location where you can express your opinions, but our best guess is at Regulations.gov. If Federal Motor Vehicle Safety Standard No. 141 turns into law, expect it to be phased in over a period of three years beginning in September of 2015.