[ProtectOurFreedom]

Your GPS will show "405." Southern Californians always put the definite article "the" in front of their freeway numbers.

The 5, the 101, the 405: Why Southern Californians Love Saying 'the' Before Freeway Numbers
Why Do Southern Californians Say “The” Before Freeway Numbers?
How Los Angeles got in the habit of putting ‘the’ in front of every freeway name

I think it takes the place of saying "Ya-all."

[steve86]

Thank you. I’m two states north and have driven THE 405 several times as well as THE 5 and THE 101 but did not know that.

[NonValueAdded]

Orlando Florida radio hosts have also adopted using “the” in front of route numbers.