Henry Ford famously said a customer can have a car in "any color that he wants, as long as it is black."
Butblack on self-driving carscould be deadly.
That can help explainwhy the May Mobility self-driving shuttles in downtown Detroit have a white base and whypaint companies and carmakers have beenworking diligently overthe past four to five yearsto get the color spectrum just right for future vehicles.
"Highly-reflectivecolors like white are more detectable by lidar systems," said Nancy Lockhart, color marketing manager at Axalta Coating Systems in Clinton Township. "Black will be the least reflective."
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The Light Detection and Ranging (lidar) remote sensors thatuselightto measure ranges in distance won't be able to "see" dark-colored cars or less-reflective paint colorsas well as the more reflective, lighter colors, experts say. That could be asignificant problem — leading to crashes —when the roads are shared with autonomous vehicles one day.
"All the colors on vehicles today or road signs, road markings, are all designed for our eyes," said David Bem, vice president of science and technology and chief technology officer for PPG in Pittsburgh.
Human eyes can adjust, thereby absorbingvariouslight acrosscolor spectrums, Bemsaid. PPG has studied the aerospace industry for years to learn how sensor technology reacts to various colors and reflection. Bemsaid as the car industry goes to "sensor technologies or anything working off a wavelength,"the visibility spectrum across light to dark colors can impact how those sensorsdetect and react.
"Dark colors tend to absorb" light, making it hard for sensors to see, Bemsaid. But,"Those that reflect well have the opposite effect and can, in extreme cases, blind sensors," he said.
Axalta and PPG scientists are developing and testinga full range of colors that will be visible to lidar systems in a variety of weather conditions and lighting.
The popular metallic colors such assilver create a challenge, because, "If you walk around a highly metallic vehicle, the color changes in different light," said Lockhart. "So those colors tend to be more complex in determining how reflectivethey will be on the road because you have AVs coming at it at all angles."
But the AV industry is so new that thelack of rules and methodsfor testing AV paint makes the progress fordeveloping itslow going, Lockhart said. Axalta has devisedits own test methods and devices to monitor how the various colors it tests will perform in different environments, shesaid.
"We're working as aggressively as the industry will let us, but right now there is no pass or fail," Axalta's Lockhart said. "There are no regulations as to testing the AV detection systems, so we are looking at how do we best detect things. There is no worldwide testing unit or spec that says this is what you have to test."
Axalta developscolors in Mount Clemens, then sends them to a new technology center it built near Philadelphia for testing on the vehicles and in environments, Lockhart said.
PPG has developed a coating that allows automakers to better manage the reflectivity of specific light wavelengths, Bemsaid. Within two years, PPGwill bring to market advanced coatings that will absorb less infrared light, but still provide beautiful color, he said.
PPG has also developed a "portfolio of composite coatings" tomake it difficult for dirt, water, bugs and road debris to block sensor lenses.
Besides the obvious safety advantage of having the right paint color detectable by AV sensors, there might be a financial advantage too. Lockhart suggests thatinsurers might offera discounted rate to drivers with cars that have a higher-reflective paint.
Lockhard is confident of one thing: Theworld will not returnto the days of Henry Ford's monochrome car fleet.
"I don't think we'll get to a world that is so vanilla that we can't have different colors," said Lockhart. "The industry will find a way to get there."
Contact Jamie L. LaReau: 313-222-2149 or jlareau@freepress.com. Staff writer Phoebe Wall Howard contributed to this report.
