MileCheckWhy is there no Interstate 50 or Interstate 60?
Look at a US interstate map and you'll find I-40 and I-70 — but no I-50 or I-60. It's not an oversight. The numbers were deliberately skipped, and the reason is about avoiding confusion.
Two road systems share the same numbers
The US has two separate numbered systems: the older US routes and the newer interstates. Both use one- and two-digit numbers, so the same number can exist in each. Usually that's fine because the two roads are far apart.
I-50 and I-60 would collide with US-50 and US-60
But US-50 and US-60 are major east–west highways that run right across the middle of the country — exactly where an east–west I-50 or I-60 would fall (interstate numbers climb south to north, so 50 and 60 land mid-map). Signing an "I-50" near "US-50" in the same region would confuse drivers, so planners simply avoided those numbers.
It's a guideline, not an airtight law
The rule of thumb is to not duplicate a two-digit interstate and US route in the same part of the country. It's followed closely for big cross-country numbers like 50 and 60, though the system isn't perfectly consistent everywhere. The result is the gap you notice on the map.
Reading the rest of the grid
The rest of interstate numbering is very logical once you know it — odd numbers run north–south, even run east–west, and they climb from west to east and south to north. See how interstates are numbered → Wherever you are on the grid, MileCheck shows your exact mile marker in real time.
Know exactly where you are — live
MileCheck shows your nearest mile marker in real time as you drive, plus live DOT alerts and the nearest camera on your route. Free to start, works offline, runs on CarPlay and Android Auto.
Questions, answered
Why is there no Interstate 50?
To avoid confusion with US Route 50, a major east–west highway across the middle of the country — right where an east–west Interstate 50 would fall. Planners skipped the number rather than sign both in the same region.
Why is there no Interstate 60?
Same reason as I-50: US-60 is a major mid-country east–west route, and an Interstate 60 would run through the same area, so the number was avoided to prevent confusion.
Are other interstate numbers skipped too?
The guiding rule is to avoid giving a two-digit interstate the same number as a US route in the same region. I-50 and I-60 are the most famous gaps because US-50 and US-60 are prominent mid-country routes.
Is 'Interstate 60' a real highway?
No. There is no Interstate 60 in the US system — the number was intentionally not used. (It's also the title of a 2002 movie, which is fictional.)