what is the primary interstate that travels through florida that leads to key west?
Understand[edit] The north terminus of U.S. Highway 1 has always been in Fort Kent, Maine, and until 1926 the route ended in Miami, Florida. In 1938 it was extended to Key West, Florida. It is also the longest north-south highway in the United States. Although a good part of the route hugs the Atlantic coastline, much of it is quite distant from the coast. Originally, US 1 was built to provide quick travel before the Interstate system was built.