Driving to Key West: What to Know Before the Overseas Highway

The drive from Miami takes several hours even before sightseeing stops. Use a current navigation estimate for your starting point and departure time.

Do not build your day around that minimum.

The Overseas Highway is not an interstate where losing 20 minutes is easily recovered by the next wide-open stretch. Traffic, bridge work, incidents and the simple fact that you will probably want to stop somewhere can all extend the trip.

If you need to be in Key West for a fixed dinner reservation, boat departure or event, leave margin.

Once you enter the Florida Keys, U.S. 1 becomes the Overseas Highway.

The small green mile-marker signs descend as you travel toward Key West: the numbering begins around 127 south of Florida City and eventually reaches Mile Marker 0 in Key West. Businesses and directions throughout the Keys frequently use these mile markers as geographic reference points.

Once you understand that lower number = closer to Key West, directions become much easier to interpret.

The Overseas Highway is the only continuous roadway in and out of the Keys, and much of the route is constrained to a narrow island corridor.

That is why a single serious incident can matter far more here than it would on a normal urban freeway network.

Before leaving South Florida, check FL511, the Florida Department of Transportation's official real-time traffic source. It provides information on congestion, incidents, construction, road closures and traffic cameras.

Check again during a stop if conditions appear to be changing.

Bridge and roadway work occurs regularly along the Keys.

Current construction examples should not become permanent landmarks in an evergreen article because those projects will eventually finish and others will replace them.

The durable advice is:

Check current road conditions before departure rather than memorizing a list of construction zones from a travel article.

The Overseas Highway crosses dozens of bridges as it moves from island to island, including the Seven Mile Bridge near Marathon. The official Florida Keys tourism council lists 42 bridges along the drive.

You do not need to turn the trip into a full-day sightseeing itinerary.

But if you have never driven the Keys before, planning time for one deliberate break is usually more satisfying than racing from Miami to Mile 0 while watching the scenery through the windshield.

If you want multiple stops, treat the drive as part of a travel day rather than as transportation before the “real” vacation begins.

The Lower Keys are habitat for endangered Key deer.

The U.S. Fish & Wildlife Service specifically asks motorists to drive cautiously through Key deer country from Big Pine Key toward the Lower Sugarloaf Keys and notes that vehicle collisions are particularly dangerous at night.

Follow posted limits and stay alert.

Do not stop in an unsafe traffic position to photograph wildlife, and do not feed or approach deer.

You can, but you lose much of what makes the drive distinctive.

If the purpose of driving rather than flying is partly to experience the Keys, daylight is preferable.

Driving after dark can make sense when schedule or airfare dictates it, but wildlife visibility becomes another concern in the Lower Keys, and the ocean-and-bridge scenery largely disappears.

For a first drive, daylight is the better experience.

This is an important distinction.

Driving to Key West can be worthwhile while driving around Key West every day can be unnecessary.

If your accommodation includes parking and you are staying near Downtown or Old Town, it may make sense to leave the vehicle there for much of the trip.

City parking in and around the historic core includes paid municipal spaces and residential permit areas, so repeatedly moving the car can create work without saving much time.

The vehicle becomes useful again when the itinerary points back up the Keys.

Do not schedule an arrival day like this:

Leave Miami at noon → arrive precisely at 3:45 → check in at 4:00 → reservation at 4:30.

Plan it more like this:

Leave South Florida with enough daylight and margin to absorb a stop or slowdown. Arrive, park, check in and keep the first evening relatively flexible.

That works particularly well for a first trip because Key West does not require a complicated first-night plan. A walk, dinner and the waterfront are enough.

Yes, the Overseas Highway is a practical route to Key West.

It is also a road where adding time is smarter than optimizing time.

Start with the assumption that the fastest GPS estimate is the floor, not the schedule. Check FL511, respect wildlife zones, and decide in advance whether the drive itself is transportation or part of your Florida Keys experience.