Possible Clues:

• Maine-to-Fla. highway
• Eastern seaboard rte.
• Its mile zero is in Key West, Fla.
• It joins I-10 in Jacksonville and I-90 in Boston
• In Key West it's known as the Overseas Hwy.
• Much of the Boston Post Rd., now
• Rte. through six Eastern state capitals
• Rte. that runs from Key West to Fort Kent
• Hwy. paralleling I-95
• Artery from Maine to Florida