'the interstate'

It's been on my back burner for awhile ~ that drivers outside of California tend to refer to state highways (i.e.: I-80) as 'the interstate', which of course, they are - 'I' for interstate. Yet - here in California, we usually say 'Just get on 80' (or other highway number designation). You don't often hear drivers call '80' or '5' using the (to my ears) more formal 'the interstate'.
Or do we actually say 'Get on the interstate' and I'm just not paying attention (surprise surprise).

Some time ago, I traveled a lot in the eastern U.S., which was when I first noted judicious use of the term the interstate (as well as the turnpike, for that matter). [Check out the labyrinth of interstates on the eastern half of the map - wow - the interstate must have some real meaning there!]

The other week, an acquaintance (from Omaha Nebraska) and I were in a rental car, tootling around the environs of Las Vegas. Sans GPS, we turned corner after corner navigating back streets and main streets towards our (shopping) destinations. Though content to meander thusly, she did keep wondering aloud which way 'the interstate' was. Time and time again, she stated 'We need to get on the interstate', as if it were a lifeline (which, in many ways, it is).

The interstate.
The interstate.
Do Californians not utilize the word 'interstate' as much because most of our daily/ weekly driving is within the state? We drive the 'I' roads, but don't usually refer to them as the interstate(s). Do we have less need (or desire) to make frequent drives across state lines as often as those in other states might? From The Bay Area, it's a 4+ hour hop into Western Nevada, should you even wish to go there....but to Oregon or Arizona - for many Californians - is beyond the scope of an easy day's drive. Consider the length (less the breadth) of Calfornia's size and it becomes obvious that considerable effort / time is required to venture out of state....into and through other states... where the interstate would lead us.

Could it be that drivers from other states rely more heavily on access to 'the interstate' to get them the-hell-outta-Dodge on a regular basis? As in 'I'm going to jump right onto the interstate to get-the-hell-outta-Dodge today!' For those needing to escape Dodge on a regular basis, does the interstate hold more significance?

Do we in California not say the interstate quite as often because California is the proverbial end of the interstate line, therefore we don't go by car beyond the state (west being accessible only by boat or plane) and only on occasion venture back (eastward) or north or south to neighboring states?

Is this state actually more like an all-inclusive island, then? With no real need to obsess 'interstately'?
To be sure, some may view California thusly...

In any case, the phenomenon of the interstate is something to ponder... at least on a lazy Tuesday morning when I should be cleaning house, it is...