The road follows a trail originally blazed in 1912 when railroad baron Henry Flagler completed the extension of his Florida East Coast Railroad from Miami to Key West. The railway ceased operation after severe damage to its infrastructure in 1935.
The highway’s foundation, completed in 1938, incorporated some of the original railway spans as well as the coral bedrock of individual keys and specially constructed columns.
The Overseas Highway represents a remarkable engineering feat: 113 miles of roadway incorporating 42 bridges that leapfrog across the water from key to key. The Atlantic Ocean lies on one side of the highway, with Florida Bay and the Gulf of Mexico on the other — providing drivers breathtaking vistas of open sea and sky.
In 1982, construction was completed to replace 37 of the original bridges with wider spans, including the renowned Seven Mile Bridge (actually 6.79 miles long), one of the world’s longest segmental bridges, at Marathon.
Travelers along the Overseas Highway will see mile markers, also called mile posts, on road shoulders. These green signs have white numbers and descend in order from mile marker 113 at the Miami-Dade/Monroe County line to marker 0 at the corner of Fleming and Whitehead streets in Key West.
Awareness of these markers is useful, since Keys residents refer to them regularly when giving addresses. Visitors asking for directions shouldn’t be surprised to hear that the spot they’re seeking is located at, just before or just beyond a certain mile marker number.
The highway also is the foundation for the Florida Keys Overseas Heritage Trail, currently under development. The trail is defined as a multiuse bicycle and pedestrian thoroughfare, planned to extend 106 miles from Key Largo to Key West.
Today, drivers can leave Miami and travel the full length of the Overseas Highway in less than four hours. Travelers should, however, plan for additional time to experience the natural beauty of the ever-changing land and sea bordering the roadway, as well as sunrises and sunsets that can be viewed from this unique highway.
Florida Keys visitor information: fla-keys.com or 1-800-FLA-KEYS
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