What is it? Where is it?

[HiloJulie]

You mean state Route 11 aka  Māmalahoa Highway? That is a long road, which I have yet to traverse in its entirety. Perhaps I should just book the Circle the Island tourist trip around the Belt Road (11, 19, 190) for $29?

NOPE! It's not on the "belt" road, aka Hwy 11, aka Mamalahoa Highway.

Again, kalianna had the closest guess so far. And as was originally said, this sign USED to be on the road in question. And to reconfirm, if you drove this road in one direction it would lead you to Hwy 11 but if you drove it the other way, where you would have seen this sign, you could be on your way to Pahoa!

Also, one more hint, in addition to the road this Aloha sign was on having a name and a number, it also has an acronym!