I think it is usually multiples of 10 as well so for example I-5 runs from the border in San Diego (or close enough) to the border with Canada. I-10 runs from LA in California to Jacksonville Florida, smaller routs ending in 2, 4, 6, or 8 are small sections that terminate a few towns over usually or connectthe bigger highways to eachother.
Basically, routes meant to serve a metro area/region instead of being actually cross-country – “Interstates” that don’t actually go inter-state. Think ring roads around cities and whatnot.
Three digits starting with even are loops, with interstates at both ends, starting with odd are spurs, with interstates at one end. Thats why I-495 can be both the capital beltway and loop around boston
If you want a challenge, southwest of Boston there’s a short stretch of overlapping interstates where you can be headed north on I-95 while heading south on I-93
Oh yeah, I always hated that. I used to visit my ex’s parents down in that direction and I knew the way from having driven it every year but if I tried to give directions I never could remember which is 287 and which is 278
It’s really not that complicated. The only other direction to go on I-65 is north.
Interstates with odd numbers run north and south. Even numbers run east and west.
I think it is usually multiples of 10 as well so for example I-5 runs from the border in San Diego (or close enough) to the border with Canada. I-10 runs from LA in California to Jacksonville Florida, smaller routs ending in 2, 4, 6, or 8 are small sections that terminate a few towns over usually or connectthe bigger highways to eachother.
Nah.
Around here I-76, I-78, I-80, I-84 (what happened to 82? I don’t know); are all major roads that go through multiple states
Going the other way 81, 87, 95 are all significant
Ah, interesting. The number of digits means something too. 3-digit numbers are… Some other kind of routes. I’m too tired to remember exactly 🤦🏻♂️
Edit: auxiliary routes
Basically, routes meant to serve a metro area/region instead of being actually cross-country – “Interstates” that don’t actually go inter-state. Think ring roads around cities and whatnot.
The way I always remember is both North and South have an odd amount of letters (5), and East/West have an even amount of letters (4).
In what world is that not complicated
How could it be less complicated?
Sure, but use Google maps and have a look at “i-435”
And I thought I-45 being an “interstate” that only exists in Texas was bad!
There are interstates in Oahu if that helps, ha ha
Also Alaska and Puerto Rico! The interstate signage is more about the funding source than where the highway actually goes.
Three digits starting with even are loops, with interstates at both ends, starting with odd are spurs, with interstates at one end. Thats why I-495 can be both the capital beltway and loop around boston
If you want a challenge, southwest of Boston there’s a short stretch of overlapping interstates where you can be headed north on I-95 while heading south on I-93
Similar overlaps over in NY with 87/287, and 95 does something shifty near there also.
Edit: and to make things more confusing, there is a 278 in the area also. In fact I can’t remember which one is the 87 overlap lol.
BTW there are multiple I-495s and 2/5 are Spurs
Oh yeah, I always hated that. I used to visit my ex’s parents down in that direction and I knew the way from having driven it every year but if I tried to give directions I never could remember which is 287 and which is 278