Why does it need to go under the bridge anyway? There are extensive quay facilities outside the bridge(the cruise ship terminal and the tank farm just north of

Why does it need to go under the bridge anyway? There are extensive quay facilities outside the bridge(the cruise ship terminal and the tank farm just north of it). https://www.openstreetmap.org/#map=16/-42.8766/147.3363 https://www.openstreetmap.org/#map=16/-42.8766/147.3363