Every address in the Florida Keys is a mile marker, and the numbers count down. Learn that before you start the car and the road explains itself.
How the mile markers work
The Overseas Highway is US-1, and along it stand small green posts with white numbers. They start at about MM 126 in Florida City on the mainland, pass MM 106 at the top of Key Largo, and end at MM 0 in Key West, marked by a sign at Whitehead and Fleming Streets. Every business, park and turn-off is given as a number (“Robbie’s, MM 77.5”), and the number is roughly the miles left to Key West.
The other half of an address is the side of the road. “Oceanside” is the Atlantic side, on your left driving south. “Bayside” (or “gulfside” past Marathon) is the Florida Bay side, on your right. Sunset bars are bayside for a reason.
Two ways out of Miami
Both start on Florida’s Turnpike, south to its end in Florida City, about 45 minutes from downtown without traffic. The tolls are electronic; a rental car usually carries a transponder with a daily fee. Fuel is cheapest here, so fill up.
US-1 straight on puts you on the 18-Mile Stretch and into Key Largo.
Card Sound Road peels off to the left a few minutes south of the Turnpike’s end. It is two lanes through mangroves with nothing on it until Alabama Jack’s, the open-air bar on stilts at the foot of the Card Sound Bridge. The bridge has a small electronic toll (a dollar or two, no cash booth, so you need a SunPass or expect a bill by plate; check before you go), then the road rejoins US-1 at MM 106. It adds 15 to 20 minutes and it is the better way in; the back road into the Keys covers it. No fuel, no shade, thin phone signal.
The 18-Mile Stretch
Stay on US-1 and the road from Florida City to Key Largo is what locals call the Stretch: 18 miles of two-lane highway through mangrove and marsh with a concrete barrier down the middle for most of its length. You cannot pass, so whatever is ahead sets the pace, and a wreck closes it both ways. It ends with the high bridge over Jewfish Creek at MM 108, and the view from the top is where the Keys begin.
Realistic driving time
Miami to Key West is about 160 miles and takes 3.5 to 4 hours without stops on a quiet weekday. The limit is 45 mph on most of the road, 35 through the towns and 55 on a few open stretches, and it is enforced. Key Largo, Marathon and the approach to Key West have four-lane sections; most of the rest is one lane each way with few passing zones, so there is no way to make up time.
Friday afternoons and Sunday afternoons, when Miami empties into the Keys and drains back, make it five or six hours. Holiday weekends, Fantasy Fest in late October and the two-day lobster mini-season in late July are worse. Leave Miami before 8am, and do not book an evening flight out of Miami for the Sunday you leave.
The bridges, by mile marker
There are 42 bridges. The two that matter:
- Seven Mile Bridge, MM 47 to 40: the long bridge over turquoise water, a clear match for the trailer’s long bridge. The 1912 railroad bridge beside it is walkable for 2.2 miles from the Marathon end to Pigeon Key, with a ferry ($10-20 per person, check the schedule) for the ride back. Free parking at the old bridge.
- Bahia Honda, MM 37: the broken truss bridge over the beach under the old bridge; park entrance oceanside.
You cannot stop on the bridges. There is no shoulder and nowhere to stand, and a photo stop on the Seven Mile Bridge is illegal and causes wrecks. Shoot from the old bridges, the parks, or the passenger seat.
The Leonida Keys places, in road order
Jason lives in the Leonida Keys, and every location on this site matched to his home turf sits on or just off US-1. Southbound:
- Card Sound Road and Alabama Jack’s: before the Keys begin.
- The Overseas Highway itself, from MM 106 down.
- Jason’s place: canal homes: Key Largo’s side streets, MM 95 to 105.
- Betsy the Lobster: Rain Barrel Village, MM 86.7 bayside.
- Islamorada’s bayside tiki bars: MM 77 to 85 bayside.
- The mangrove backcountry: by boat from Robbie’s, MM 77.5.
- Seven Mile Bridge: MM 47 to 40.
- Bahia Honda State Park: MM 37 oceanside.
- Key West and Duval Street: MM 0.
For a three-day plan with nights in Islamorada and Key West, use the Leonida Keys road trip. That page is the itinerary; this one is the driving.
Fuel, food and the rhythm of the road
Fill up in Florida City and again in Marathon, because prices climb as you go south. Every town has fuel; the longest gap is about 17 miles, from Marathon to Big Pine Key.
Food falls into the road on its own: breakfast in Key Largo (Mrs. Mac’s Kitchen, MM 99.4), a late lunch in Islamorada (Robbie’s, MM 77.5) or in Marathon (Keys Fisheries), then dinner in Key West. Expect a wait at all three rather than a reservation.
The state parks are the reliable bathroom stops: John Pennekamp (MM 102.5), Long Key (MM 67.5), Curry Hammock (MM 56) and Bahia Honda (MM 37), a few dollars a car. Big Pine Key, MM 30 to 33, drops to 45 mph by day and 35 at night for the Key deer, which do walk into the road at dusk.
Parking and one-way streets in Key West
Old Town is a grid of short blocks and narrow streets, many one-way, with residential-permit parking on many of the curbs. Park once and leave the car: the city garage on Grinnell Street by the Historic Seaport, or your hotel’s lot (many charge). Budget $20-40 a day, and check. Then walk, rent a bike, or book Key West Rides, the city’s on-demand shuttle, which replaced the free Duval Loop bus in January 2026 (check the city’s transit page for fares and hours).
Getting back
The road is the only road. Driving back is the same 3.5 to 4 hours, worst on a Sunday afternoon. Two alternatives:
Fly out of Key West (EYW). The airport is ten minutes from Duval, with direct flights to Miami year round and to a handful of other US cities, several only in winter; check the schedule. One-way rental drops exist, but price the fee first.
The Key West Express ferry. A passenger-only fast ferry runs from the Historic Seaport to Fort Myers Beach in about 3.5 hours; expect roughly $120-180 per adult one way, and check before you go. It does not carry cars. It turns the trip into a loop: down the Keys, across to Fort Myers, then back to Miami on Alligator Alley or the Tamiami Trail, Grassrivers country.
What a first-timer gets wrong
They treat US-1 like a highway. It is a 45 mph road with traffic lights, boat trailers and people slowing down to look.
They leave Miami at 4pm on a Friday.
They plan a beach day along the road. The Keys have very few natural beaches; Bahia Honda is the best of them.
They try to photograph the Seven Mile Bridge from the Seven Mile Bridge.
They have a sunset drink in Islamorada and drive on. The road is dark, two lanes and patrolled. Stay where you drank.
They do it in a day and remember only the windshield. Give it two nights, stop when something looks good, and count the mile markers down slowly.
Updated September 28, 2026. All guides