Coastal Highway (achievement)

Coastal Highway is an Achievement in Halo 3: ODST. It is unlocked when the player completes at least on normal difficulty in Campaign Mode and unlocks the map  for Firefight. It is worth 50 Gamerpoints.

It is represented by an olive circle, with the Marathon symbol imprinted in it, with a Waste Disposal Elephant (otherwise know as an Oliphant) in front of it.