"when you arrive at the street corner"
Translation:ke hiki ʻoe i ka huina alanui
I can't say if it's ever used that way, but that is not what it is doing here. The "i" here is marking the location: "i ka huina alanui" "at/on the street corner". It seems like the particle "ke" before the verb "hiki" ("arrive") is what's implying the conditional future "when".