The National Highway Traffic Safety Administration published a proposed rule for a new Federal Motor Vehicle Safety Standard to require pedestrian alarms on all new hybrid and electric vehicles. The NPRM comes after a notice of intent was published in July 2011 and was called for in the Pedestrian Safety Enhancement Act of 2010.
School buses would be among the vehicles equipped with pedestrian safety sound systems, or PEDSAFE, that emit sound in certain operating conditions to alert pedestrians of the vehicles' presence. The alarms would especially benefit blind and other visually impaired pedestrians as well as senior citzens and smaller children, said U.S. Transportation Secretary Ray LaHood.
A message left with NHTSA for additional comment was not returned at this writing.
The new FMVSS 141 would prescribe minimum alarm sound standards that would be detectable under a wide range of street noises and other "ambient background" when a hybrid or electrical vehicle would be traveling at speeds of less than 18 miles per hour. Above this speed, NHTSA said these vehicles make sufficient noise for pedestrians and bicyclists to hear them without an alarm.
NHTSA estimates that 2,800 fewer pedestrian and bicycle injuries would occur over the life of each model year of hybrids and electrics versus those without sound.
"Our proposal would allow manufacturers the flexibility to design different sounds for different makes and models while still providing an opportunity for pedestrians, bicyclists and the visually impaired to detect and recognize a vehicle and make a decision about whether it is safe to cross the street," said NHTSA Administrator David Stickland.
NHTSA first held a public meeting in June 2008 to discuss technical and safety policy issues associated with electric and hybrid vehicles and quiet internal combustion engines and the risks those vehicles can have for the visually impaired. Two studies resulted from that meeting, one in October 2009 that examined the rates of collisions of these vehicles with pedestrians, and another in April 2010 that found that quieter vehicles, especially electric and hybrid vehicles operating at low speeds, may present safety issues.
Sound levels for hybrid-electric vehicles that were tested were lower at low speeds than those of internal combustion engines. Additionally, NHTSA said that human response times differed depending on the vehicle tested. Along came the Pedestrian Enhancement Act to do something about it, namely to require electric and hybrid vehicles to emit an alert that allows pedestrians to "reasonably" detect the presence, direction, location and operation of the approaching vehicle.
The law covers all types of light-duty passenger vehicles as well as low-speed vehicles, motorcycles and medium- and heavy-duty buses and trucks. School buses fall in the latter category.