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Why there's a highway sign in kilometers on th...
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This is interesting, if you're interested. 🙂

By Silas Valentino Jan 12, 2024 - SFGATE

While driving east down Interstate 580, observant drivers might notice a sign unlike any other in the Bay Area.

“Livermore 17 mi / 27 km and Stockton 56 mi / 90 km,” it reads.

The use of kilometers on the sign — why it’s there and why it hasn’t come down yet — illustrates the complicated history behind America’s standards for measurements.

Caltrans couldn’t confirm whether there are other highway markers in the Bay Area that also include kilometers, which suggests that the one on I-580 is one of the oddest signs in the region.

The agency installed it on I-580 more than 30 years ago, but the story of why it appeared in the first place is much older. It’s marked by numerous starts and stops for embracing the metric system, and even includes a tale of a tragic hijacking by pirates in the Caribbean.

Why there's a highway sign in kilometers on the Bay Area's Interstate 580


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