The term 'MAIN LANE' can be summarized by two crossword solutions: SEAWAY (6 letters) and ARTERY (6 letters). SEAWAY is a navigable route for ships, usually connecting two bodies of water. An ARTERY is a blood vessel that carries oxygenated blood away from the heart to the rest of the body. Both terms are related to transportation, with SEAWAY referring to the transportation of goods and people by sea, and ARTERY referring to the transportation of oxygen and nutrients throughout the body.