The railway ceased operation after severe damage to the infrastructure in a 1935 hurricane. Construction of the highway began in the late 1930s. Its foundation included some of the original railway spans as well as the coral bedrock of individual keys and specially constructed columns.
When it was completed in 1938, the highway marked the beginning of an incredible adventure for the North American motorist who travel 113 miles of roadway and cross 42 bridges to get from Miami to the southernmost point in the continental U.S. — Key West. In 1982, 37 bridges were replaced with wider spans, including the well-known Seven Mile Bridge at Marathon.
In 2002 the Florida Keys Overseas Heritage Trail was added, which includes the Grassy Key Bikeway. The Heritage Trail is a paved recreational path along old Flagler railroad bridges and the Florida Department of Transportation right-of-way that features crossways between bayside and oceanside.
Today, motorists can travel the highway in less than four hours from Miami. However, drivers should allow time to experience the natural beauty of the ever-changing scenery of the seas and wilderness bordering the roadway, and the wonder-ful sunrises and sunsets.