The National Highway Transportation Safety Administration has announced a new requirement for electric and hybrid cars: an audible alert. Beginning in September 2019, all new production hybrid and electric cars will have to comply with a minimum noise level in an effort to both prevent collisions with pedestrians and bicyclists as well as assist blind/low vision pedestrians in identifying approaching vehicles. The NHTSA Rule docket assumes that by 2020, hybrid and electric cars will comprise four percent of the total vehicles registered, and that adding this sound requirement will avoid 2,464 accidents involving bicyclists and pedestrians.
The NHTSA press release states, “Under the new rule, all hybrid and electric light vehicles with four wheels and a gross vehicle weight rating of 10,000 pounds or less will be required to make audible noise when traveling in reverse or forward at speeds up to 30 kilometers per hour (about 19 miles per hour). At higher speeds, the sound alert is not required because other factors, such as tire and wind noise, provide adequate audible warning to pedestrians.” To be clear, the vehicles are not required to emit a noise when they are stationary, either stopped at an intersection or in “park.”
These safety regulations are not unique to the United States; similar laws exist around the world. Japan was a trailblazer in this space, with guidelines concerning electric/hybrid vehicle noise requirements released in early 2010. The UK Department for Transportation (DfT) commissioned its Transportation Research Laboratory to investigate the role that vehicle noise plays in averting vehicle-pedestrian accidents. The study’s findings, published in 2011, revealed that there is almost no correlation between vehicle noise level and an increase in vehicle-pedestrian accidents, and noted that some internal combustion engine vehicles are quieter than some hybrids. Nevertheless, the UK elected to implement a requirement for sound generating devices to be installed on electric and hybrid vehicles. In the EU, an April 2014 law mandated the installation of an “Acoustic Vehicle Alert System” or AVAS on all hybrids and electric vehicles. The AVAS operates at speeds 12 mph and below, and is required to be installed on all 2019 model year electric and hybrid vehicles.
Several car manufacturers have already implemented some sort of noise generator on their plug-in cars. The Nissan LEAF features the “Vehicle Sound for Pedestrians” or VSP system that functions when the vehicle is traveling at less than 16 mph or in reverse. Ford, Toyota, and Hyundai have all developed compliant pedestrian warning sound systems and are ready to mount them on their respective hybrid and electric cars.
These new laws have no been without their fair share of criticism, however. Some contend that these alert systems constitute noise pollution, and counteract one of the greatest features of electric cars: their serene silence. Others point to the UK DfT study, which states that some hybrids are actually louder than their internal combustion engine-only counterparts. Check out a blog by our Chief Science Officer, Tom Saxton, regarding quiet vehicles and pedestrians here.
What do you think? Do electric and hybrid cars need more cowbell? Let us know in the comments below.