The Miami-to-Key West drive crosses 42 Overseas Highway bridges from Key Largo to Key West.
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The bridge count is not a Miami count at all: the answer to how many bridges from Miami to Key West is 42 if you mean the famous Florida Keys stretch of U.S. 1. That count belongs to the Overseas Highway from Key Largo to Key West, not every city bridge or overpass you might pass before leaving Miami-Dade.
The useful way to think about the drive is simple: Miami gets you to the Keys, then the Keys give you the 42 water crossings. The big moment most travelers remember is the Seven Mile Bridge near Marathon, but the full count is spread across the Upper, Middle, and Lower Keys all the way to Key West.
How Many Bridges Do You Actually Cross?
Drivers cross 42 bridges on the Overseas Highway section of the Miami-to-Key West trip. The official Florida Keys tourism site describes the Key Largo-to-Key West roadway as 113 miles with 42 bridges over the Atlantic Ocean, Florida Bay, and the Gulf of Mexico.
The number can feel confusing because the drive starts in Miami, while the quoted bridge count starts in the Florida Keys. A traveler leaving Downtown Miami, Miami Beach, or Miami International Airport may cross local causeways, expressway ramps, or canal bridges before reaching U.S. 1, but those are not part of the 42-bridge Overseas Highway count.
For the road trip most people picture, the count begins once U.S. 1 reaches the Keys near Key Largo and continues until the road runs out at Mile Marker 0 in Key West. The route is easy to follow because the mile markers count down as you head south.
Where Do The Bridges Start On The Miami To Key West Drive?
The Keys bridge experience starts near Key Largo, after the mainland run through South Miami-Dade and Florida City. The first big water crossing most drivers notice is around the Jewfish Creek area, then the route keeps hopping from island to island.
From Miami, expect a normal road for the first part of the trip. The scenery changes after Florida City, when U.S. 1 moves toward Key Largo and the road begins to feel less like a highway out of town and more like a chain of islands.
The bridge count matters less than the pacing. The first Upper Keys crossings are shorter and broken up by towns, marinas, and traffic lights. The Middle Keys bring longer open-water stretches, and the Lower Keys feel wider and quieter before the final approach into Key West.
Miami To Key West Bridges: What The 42 Crossings Mean
The 42 bridges are not 42 versions of the Seven Mile Bridge. Most crossings are short channel spans, while a few longer bridges define the feel of the road.
The official count is the backbone, but these are the bridge areas that help you understand the drive in order. Mile markers are approximate and count down toward Key West.
| Bridge Or Stretch | Approx. Mile Marker | Why It Matters |
|---|---|---|
| Jewfish Creek Bridge | MM 106 | The first major Keys-area crossing after the mainland approach |
| Key Largo Cut | MM 103.5 | An early Upper Keys channel before the towns tighten up |
| Tavernier Creek Bridge | MM 91 | A clear marker that the Upper Keys are underway |
| Snake Creek Bridge | MM 86 | A channel crossing on the way into the Islamorada area |
| Whale Harbor Bridge | MM 84 | A short crossing near one of Islamorada’s busy boating zones |
| Channel 2 And Channel 5 Bridges | MM 73 And MM 71 | Paired crossings that move the drive toward Long Key |
| Long Key Bridge | MM 65 | One of the longer open-water stretches before Marathon |
| Seven Mile Bridge | MM 47 To MM 40 | The longest and most famous bridge section, linking Marathon with the Lower Keys |
| Bahia Honda Area Bridges | MM 38 To MM 36 | A memorable section where old railroad-era bridge structures sit near the road |
| Boca Chica And Stock Island Bridges | MM 6 And MM 5 | The last notable crossings before entering Key West |
The official source for the core count is The Highway That Goes To Sea, which gives the 113-mile and 42-bridge figure for the Overseas Highway. That is the count travelers mean when they talk about the bridges from Miami to Key West.
Miami Bridges Versus Florida Keys Bridges
Miami-area bridges do not change the standard answer because they are outside the Florida Keys count. A hotel start on Miami Beach, Brickell, Coconut Grove, or near the airport can change the local streets you use, but it does not change the 42 Overseas Highway bridges.
That distinction helps when directions seem to disagree. A navigation app may route you over a causeway in Miami, send you through toll expressways, or keep you on surface roads toward Florida City. Those choices affect drive time and tolls, not the Keys bridge number.
For a clean mental map, split the route into three parts:
- Miami To Florida City: city and suburban driving before the island chain begins.
- Florida City To Key Largo: the gateway stretch toward the Upper Keys.
- Key Largo To Key West: the 113-mile Overseas Highway section with the 42 bridges.
Driving Time, Tolls, And Road Feel
The Miami-to-Key West drive usually takes about 3.5 to 4 hours without long stops, but the road rewards a slower plan. U.S. 1 through the Keys is often two lanes, and a crash, storm, event, or bridge work can delay the whole chain.
There is no separate toll booth for the Overseas Highway itself. Tolls can still appear on the mainland side if your route from Miami uses an expressway, so check the navigation option before you leave.
The bridge sections are safe in normal weather, but they can feel exposed in wind or heavy rain. If a squall hits, slow down, leave extra following distance, and wait for the next safe pull-off rather than stopping on a bridge shoulder.
Simple rule: count the bridges after Key Largo, not while leaving Miami. The answer stays 42 for the classic Overseas Highway drive.
Where To Stay After The Bridge Drive
Key West is the easiest place to sleep if the goal is to finish the full bridge route and park the car for the night. Staying in Key West also keeps you from doing the same 42 bridges again after dinner in the dark.
Marathon is the practical overnight split if you want the Seven Mile Bridge nearby and lower driving pressure. Islamorada works better when you want an Upper Keys stop with shorter drives from Miami and easier access to boating or fishing.
For the full finish in Key West, compare hotel locations before you commit, since parking and walkability change the trip more than a small room-rate difference:
A Simple Plan For Counting The Bridges
The easiest plan is to treat the 42 bridges as the Keys portion of the road trip, then let the mile markers do the organizing. Start paying attention around Key Largo, watch for the bigger named crossings, and save the camera work for safe pull-offs.
- Use 42 As The Real Answer. The number applies to the Overseas Highway from Key Largo to Key West.
- Do Not Count Miami Causeways. They are route-dependent and not part of the Keys total.
- Expect Variety. Some bridges last seconds; Seven Mile Bridge is the long, open-water centerpiece.
- Plan One Or Two Stops. Marathon, Bahia Honda, and the Lower Keys make the drive feel less like a transfer.
- Sleep In Key West If You Can. Finishing the bridge run is much better when you are not turning around the same day.
If you came for the clean number, the answer is 42 bridges. If you came for the road trip, the better answer is to give the drive enough time to feel the islands changing one crossing at a time.
References & Sources
- Florida Keys & Key West.“The Highway That Goes To Sea.”Supports the official Overseas Highway distance and 42-bridge count from Key Largo to Key West.