Welcome to brain Stuff, a production of iHeartRadio. Hey brain Stuff. Lauren vogelbam here and I am recording this episode live from the iHeart Podcasts Studio powered by Bows at the House of Music at the iHeartRadio Music Festival, which is wild. I'm in a little glass box at a music festival recording podcasts. But yes, okay, So you know how every single school bus in the United States is painted the exact same color. This hue is officially known as National
school Bus Glossy Yellow. But it wasn't always that way. A century ago, kids were transported to school by all kinds of random vehicles. Because there were no federal standards. It was up to states or individual school districts to hire buses or trucks or horse drawn wagons to fairy kids to and from school. I couldn't figure out if anyone actually used fairies. I did look, But in the nineteenth thirties, a man by the name of Frank Sear didn't like the system. He was a professor at Columbia
University's Teachers College and an advocate for rural education. Sear traveled the country conducting a study of school transportation, and upon finding that safety standards were often hit or miss, he decided that something needed to be done to keep America's school kids safe. So in nineteen thirty nine, Seer organized a conference in New York City dedicated to improving
and standardizing the American school bus. He invited educators, state transportation officials, and bus manufacturers to help design a newer, safer school bus. At that historic meeting, conference attendees proposed forty four national standards for the modern school bus, from its dimensions to its doors to the width of its aisle. But the standard that made Seer famous was school bus yellow.
According to William Seer, Frank's son, his father set out to find a school bus color that would not only be easily the from a distance, but also distinctive. William told The New York Times back in twenty thirteen quote, they wanted a color that would stand out, that other drivers could see from a distance, and that would be identified with a school bus, so whenever we saw it would think there's a group of kids going someplace. Before
that they sent kids to school and anything. Before the conference, Frank Seer laid out color samples on his office desk and instinctively gravitated toward orange. Adjacent shades a spectrum of colors ranging from deep orange red to bright lemony yellow. At that nineteen thirty nine meeting, Sear hung up fifty paint swatches on the walls of the conference room and
selected a special committee to pick a winner. They chose the iconic orange yellow hue that was originally known as National school Bus Chrome, so called because it was this lead based paint made with chromium. However, because lead based paint is toxic and chromium can damage DNA in the lungs if it's inhaled, the formulation for school bus yellow it was changed in the intervening decades, and yeate for that.
At the close of the conference, Sear published a forty two page booklet proposing the nation's first school bus standards, and the cover of the booklet was, of course, school bus yellow. Seer wasn't a scientist or a safety expert, but he instinctively made the connection between bright colors, visibility and vehicle safety. For the articles episodes based on How Stuff Works, spoke with doctor Stephen Solomon, a retired optometrist and founder of Visibility in Motion, which does consulting for
emergency services providers. He said, based upon the standards of nineteen thirty nine, yellow was a very intelligent choice. The colors that are most easily seen by the human eye are the yellows, the yellow green to yellow to greenish yellow. That's at the peak of the visibility spectrum. There's no color that attracts more attention or is more conspicuous than
the yellows. The human eye is literally less sensitive to colors on the ends of the visible light spectrum, that is, blues and violets on one end, and oranges and reds on the other. Our color vision is determined by photoreceptor cells in the retina called cones. There are three types of cones, each tuned to detect different wavelengths of light, red, green, or blue. Yellow light stimulates both the red and green cone simultaneously, which is why the eye is most sensitive
to colors in the yellow range. Adding to this, about eight percent of men and zero point five percent of women are red green color deficient, meaning they have difficulty differentiating between reds and greens, often observing both as sort of bland looking. The seer probably didn't even consider this, in which case it's a stroke of luck that research has shown that under all testing conditions, golden yellow is the most easily visible color for both people with color
deficiency and for people without it. Frank Seer died in nineteen ninety five, but he lived to see his yellow school buses become the national standard and an American icon. According to the National Highway Traffic Safety Administration, or NHTSA, any new school bus sold or leased in America must
meet all federal safety standards, including that bumblebee paint job. A. While yellow paint certainly makes school buses more visible and recognizable, there's a lot more that goes into making them safe. The NHTSA rightly calls school buses the most regulated vehicles on the road because modern school buses are equipped with safety features like high crush standards, rollover protections, flashing red lights, and those stop sign arms. That's because school buses carry
precious cargo. More than twenty six million American kids ride to school each day in some four hundred and eighty thousand school buses, and thankfully, less than one percent of all traffic fatalities involve children on a school bus. If they're so safe, though, why don't all school buses have
seat belts. We have a whole other episode on that, but basically, school buses are big and heavy, so they don't stop as suddenly in an actident, and thanks for design concept cold compartmentalization, children are protected from injury during a crash by closely spaced seats with energy absorbing seatbacks. Buses that weigh less than ten thousand pounds or about forty five hundred kilos are required to have seat belts,
by the way, But okay, another side question. If yellow is the most visible color, why are fire trucks still red. Fire trucks have been painted red for more than a century, though no one is sure how the custom began. From a safety and visibility perspective, red is not a great choice. Red shades are far less visible than yellows during the day and virtually disappear at night. Starting in the nineteen seventies, some fire departments switched to bright lime yellow for increased visibility,
and their safety record is impressive. In the nineteen nineties, Solomon and a colleague conducted research comparing the accident rates of traditional red fire trucks versus the new yellow engines. When one fired apartment in Dallas, Texas, used both red and lime yellow fleets. The red trucks were involved in accidents at three times the rate of yellow vehicles. Still, lots of fire departments are hesitant to make the change.
In two thousand and nine, the US Fire Administration, a division of FEMA, released a report confirming that bright yellow and fluorescent colors were more visible than red, but the agency didn't recommend a wholesale switch to yellow trucks. Their report basically said that people identify fire apparatus with the color red, and it's important to have people able to
quickly identify emergency vehicles in emergency situations. Of course, fire trucks also have allowed sirens to warn drivers and pedestrians about their approach, unlike school buses, although in some circumstances and levels of rowdiness the last day's school maybe a warning siren could be appropriate on school buses as well. Today's episode was recorded live at the iHeart Podcasts Studio powered by Bose at the House of Music at iHeartRadio
Music Festival. It's based on the article why are school Buses yellow? On how Stuffworks dot Com, written by Dave Ruse. Brain Stuff is production of iHeartRadio in partnership with HowStuffWorks dot Com and is produced by Tyler Klang. Four more podcasts my heart Radio, visit the iHeartRadio app, Apple Podcasts, or wherever you listen to your favorite shows.