Road Signs: Crunching the numbers

Another fun fact (hey, it’s fun to ME!~) is that the numbers on the road signs all have some kind of meaning, and once you understand the system, you’ll know what they mean, too!

Any two-digit highway sign (I-20, I-65, US-98, etc) means it’s a primary highway. If the numbers are EVEN, it’s an EAST-WEST highway. If the numbers are ODD, it’s a NORTH-SOUTH highway. So, I-20? East-West. I-95? North South. US-98? US Highway that’s East-West. Neat, huh? Watch this…

Any THREE digit highway (I-710, I-185, I-635) is EITHER a bypass, or a spur of the highway number.
How do you tell the difference? Well, if the FIRST number is EVEN, it’s a bypass, meaning it will reconnect with the main highway later.
If the FIRST number is ODD, it’s a spur, which means it does NOT connect back to the main highway.
So, I-710? A spur (first number ODD), off of I-10.
I-285? A bypass (first number EVEN), off of I-85.
Neat, right? Yeah it is, you nerd…… 😛

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