海かい上じょう輸ゆ送そう路ろ

• 航こう路ろ

  航路 is a more general term for a sea or air route, while 海上輸送路 specifically emphasizes the transportation of goods by sea.

• 海かい路ろ

  海路 is a broader term for a sea route, often used in historical or geographical contexts, whereas 海上輸送路 is more technical and logistics-oriented.

Compound of 海上 (maritime, on the sea) + 輸送 (transport) + 路 (route). The exact historical derivation is uncertain, but the word is a straightforward modern technical term.