1y ago

What is a well known 'public secret' in the industry you work in that the majority of outsiders are unaware of?

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Cars produce more harmful airbourne pollutants from their brakes than they do from the tailpipe. Copper is being phased out and the ultimate goal is to abandon friction braking entirely in favour of electrical regeneration.
- How much from tires when braking? I was under the impression that ~~tires~~ (edit: cats!) produce more pm2.5 from tires than brakes, which in turn account for more than the exhaust.
  
  I always understood tire deg to be microplastic/rubber not pm2.5. Brutal for the ecosystem around roadways and water bodies. Ultimately adding to the micro plastic pollution globally.
  
  The pm2.5 refers to the particle diameter and incorporates any particles that are less than 2.5 micrometers in size. So particulate matter and microplastics are not necessarily a contradiction
  But good that you brought it up, I did some googling and umweltdialog.de writes that microplastics from tires make up one third of Germany's microplastics pollution! That's an insane amount!
  It's late here, so I won't read it today, but the Fraunhofer Research Institute did a study called "TireWearMapping", which promises to contain a ton of information on the creation and distribution of tire based pollutants: https://www.umsicht.fraunhofer.de/de/projekte/tyrewearmapping.html
- Cars produce more harmful airbourne pollutants from their brakes than they do from the tailpipe.
  That's why you never live nearby a freeway or major highway.
  
  People brake less often on highways?
  
  Have you seen a highway in Los Angeles during rush hour?
  
  …Have you seen almost any other highway in the U.S. ever?
  
  That’s why you never live nearby a freeway or major highway.
  People brake less often on highways?
  Versus freeways? I would imagine not, that they would be roughly similar.
  
  Where I live, freeways and highways are the same thing, so I'm confused here.
  
  Where I live, freeways and highways are the same thing, so I’m confused here.
  Oh they're definitely different here.
  Freeways are usually eight length cement highways with an impassable divider in the middle and no buildings on their immediate sides, just off ramps.
  Highways are usually two or four lane roads that you can pull off of at any point to go to a building. They have more traffic than regular city streets, but they're not considered throughways like freeways are.
  To my point I made earlier that you reply to about the confusion, I wasn't speaking so much about breaking, but just the faster you go the more tire wear and tear and hence the more tire dust you get to breathe, as well as emergency braking for sudden stops or lane changes, etc. City streets cars are usually a little more tame and mundane speedwise than they are on highways and freeways.

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