4 ms·

The thing about federal regulations is the entire country could get stuck with a sucky implementation.

• acdha 2y ago
  Only if there’s a single product on the market. The federal regulations specify a threshold you have to reach, not a particular implementation.
  • Noumenon72 2y ago
    Yes, and a bad threshold like "cars have to panic stop if a car is under 200 feet ahead" means everyone could get stuck with a sucky implementation.
    • acdha 2y ago
      That’s why that’s not the requirement. They expect no contact at 62mph, which is roughly 2.2 seconds for that completely stopped vehicle 200’ ahead. Looking at our handy NHTSA worksheet, we can see they expect 160’ stopping distance from 60mph: https://www.nhtsa.gov/sites/nhtsa.gov/files/documents/core_participant_manual-smd-2018.pdf https://www.nhtsa.gov/sites/nhtsa.gov/files/documents/core_p... (Similar disatance: https://commons.wikimedia.org/wiki/File:Vehicle_Stopping_Distance.webp https://commons.wikimedia.org/wiki/File:Vehicle_Stopping_Dis...) So, yes, if you want to avoid a crash you have an under half a second (40 feet margin at 90 feet/second) to start braking before a collision is guaranteed. That’s legitimately an emergency situation because you really shouldn’t be driving that fast if you can’t see more than 200’ ahead, and if you’re incapacitated or unwise enough to be in that situation hard braking is much better than what would otherwise happen. Calling it sucky is like saying fire sprinklers are sucky because your wet carpet needed cleaning. In any other situation, it’s not panic braking. Nobody is going to ship something which go straight to 100% braking in normal circumstances where you have a better balance of visibility and speed.