The 405

So I was visiting Los Angeles recently. Most people know there is a highway in Los Angeles called "The 405". This got me to thinking. In Atlanta there are multiple interstates: 75, 85, 285, 20. Yet when you're in Atlanta you will never hear anyone say "Take the 285 to the 75". You would simply hear "Take 285 to 75". So why is it that interstate 405 gains that powerful "the"? In response to this, I urge everyone to add "the" to whatever interstates you have in your area. Why should those in LA have all the fun??