St. Petersburg, FL to Key Biscayne, FL is 271 miles and takes about 5h 8m via Central Avenue, 31st Street South, and Sunshine Skyway Bridge, with a fuel budget near $41 and enough daylight to finish in a day. This trip stays within Florida, primarily utilizing surface roads for most of its length. Expect a consistent drive that's manageable for a single day, especially if you get an early start. The relatively short duration and predictable fuel cost make this a straightforward option for getting from the St. Petersburg area down to the Miami vicinity.
Trip Pace
Same-day drive is realistic
A same-day return is possible, but it will make for a full day on the road.
Break Rhythm
1 planned break
Plan on a short reset every 3 to 4 hours to stay fresh behind the wheel.
Midpoint
135.5 miles from St. Petersburg, FL
A natural place for your longest stop of the day
, about 2h 29m into the drive
.
Main Roads
Road
Distance
Duration
I 75
209.3 mi
3h 44m
Sunshine Skyway Bridge
13.4 mi
15m
I 95
11.4 mi
14m
Florida's Turnpike
10.4 mi
12m
Port Everglades Expressway
9 mi
10m
I 275
6 mi
8m
Rickenbacker Causeway
5.7 mi
10m
31st Street South
0.7 mi
1m
Longest stretch:
I 75
— 209.3 mi, about 3h 44m
Traffic on I-75
Hour-of-day weekday pattern from 92 FHWA count stations on your route.
Peak
3 PM
~2,831 veh/hr typical
· worst 3,554
Quietest
2 AM
~187 veh/hr
Peak-to-quiet ratio
15.1×
busier at peak than in the quiet hours
12a6anoon6p11p
Averaged across 104 weeks of 2023 FHWA Travel Monitoring Analysis System data. Weekday hours only (Mon–Fri).
Turn-by-Turn Driving Directions
Step-by-step road directions between St. Petersburg, FL and Key Biscayne, FL.
1
Start on US 19
48 ft·5 sec·34th Street South
2
Turn right onto CR 150
0.2 mi·50 sec·Central Avenue
3
Turn right onto 31st Street South
0.7 mi·1 min·31st Street South
4
Take the ramp
0.5 mi·1 min
5
Merge onto I 275
4.9 mi·5 min·I 275
Use the straight / slight right lanes.
6
Keep slight left at fork
0.3 mi·17 sec
7
Merge onto I 275; US 19
13 mi·15 min·Sunshine Skyway Bridge
Use the straight / slight right lanes.
8
Keep slight left at fork onto I 275
1.1 mi·2 min·I 275
Toward I 75 South: Naples
9
Merge onto I 75
28 mi·30 min·I 75
Use the straight / slight right lanes.
10
Keep slight left at fork onto I 75
181 mi·3 hr 14 min·I 75
Use the straight / slight right lanes.
11
Keep slight right at fork onto I 595
9.0 mi·10 min·Port Everglades Expressway
Exit 19Toward SR 869 Toll North, I 595 East: Coral Springs, Fort LauderdaleUse the straight / slight right lanes.
12
Take the exit
0.1 mi·18 sec
Exit 8; 9A-BToward US 441: Orlando, Miami, Florida's TurnpikeUse the slight right lane.
13
Turn straight onto SR 84
0.4 mi·37 sec·SR 84
Toward SR 84 East, I 595 East, US 441: Florida's Turnpike, North Orlando, South Miami
14
Take the ramp
0.4 mi·46 sec
Exit 8Toward Florida's Turnpike, Miami South, Orlando NorthUse the straight / right lanes.
15
Keep slight left at fork
0.4 mi·56 sec
Toward Miami, Florida's TurnpikeUse the straight / slight right lanes.
16
Keep slight left at fork
0.3 mi·33 sec
Toward Miami, Florida's Turnpike South
17
Merge onto Florida's Turnpike
10 mi·12 min·Florida's Turnpike
Use the straight / slight right lanes.
18
Take the exit
0.3 mi·42 sec
Toward I 95, US 441, SR 826 West
19
Keep slight left at fork
0.8 mi·1 min
Toward I 95, US 441
20
Keep slight left at fork
0.1 mi·18 sec
Toward I 95 SouthUse the straight / slight left lanes.
21
Merge onto I 95
11 mi·14 min·I 95
Use the straight / slight right lanes.
22
Take the exit
0.2 mi·26 sec
Exit 1AToward Rickenbacker Causeway, Key BiscayneUse the slight right lane.
23
Continue on Mary Brickell Road
423 ft·7 sec·Mary Brickell Road
Use the straight / left / right lanes.
24
Continue on Southwest 26th Road
507 ft·16 sec·Southwest 26th Road
25
Continue on Southeast 26th Road
403 ft·13 sec·Southeast 26th Road
Use the left / straight lanes.
26
Continue on Rickenbacker Causeway
5.7 mi·10 min·Rickenbacker Causeway
Use the left / straight lanes.
27
Continue on Crandon Boulevard
0.6 mi·1 min·Crandon Boulevard
Use the left lane.
28
Continue on Crandon Boulevard
339 ft·15 sec·Crandon Boulevard
29
Arrive at destination
Crandon Boulevard
Trip Plan
For this 5-hour drive, leaving St. Petersburg in the morning is your best bet to arrive in Key Biscayne with plenty of daylight. Since this is a single-day trip, you have flexibility with stops; consider a quick break around the halfway point. Watch for changing speed limits as you transition through different municipalities. The $41 fuel cost is an estimate, so monitor your fuel gauge, especially with the extended surface road driving, and plan your refueling stops accordingly.
Morning Departure
An early start around 7-8 AM gets you there with plenty of daylight left.
Evening Departure
A late afternoon start means arriving after dark. Morning is better.
You can normally do this drive in one day.
Plan roughly 1 meaningful break for fuel, food, and rest.
The halfway point lands around 135.5 miles from St. Petersburg, FL, or about 2h 29m into the drive.
The longest continuous stretch on this route runs about 209.3 miles.
This is a comfortable same-day trip.
Departure
Before you leave
Start with fuel, water, and navigation already sorted so the first hour feels easy.
First stop
Around 60 miles or 1h 8m in
Use this first pause for coffee, a restroom break, and a quick traffic check ahead.
Halfway reset
Around 135.5 miles or 2h 29m in
This is the best place for your longest stop, a real meal, and a full fuel check.
Final approach
Final hour starts around 4h 2m
Traffic, exits, and arrival timing usually matter more near Key Biscayne, FL than in the middle of the route.
Before You Leave
+
Open the route before leaving St. Petersburg, FL so your first major turns are already loaded.
+
Leave with enough water and a charging cable within reach, not packed away.
+
Check your fuel range against the first long segment, especially if you are starting outside city service areas.
Day 1
Settle into the route from St. Petersburg, FL
This is one driving day of about 271 miles and 5h 8m.
Your first comfortable stop window is around 60 miles from St. Petersburg, FL.
This route can stay practical as a one-day drive if traffic stays reasonable.
Plan about 1 real break rather than only quick fuel stops.
The longest stretch is on I 75 for about 209.3 miles.
Where to Stop
Rest stops, refuel points, and overnight suggestions along this route.
Place data sourced from public business listings. Hours and availability may vary.
Heads-up: tricky spots
5 of 22
5 decision points cluster between mile 230.4 and 264.2 — GPS handles the exact turns, but know they're coming. Your lane choice matters more than the turn itself.
9
230.4 mi into trip|~4h 11m in|I 595 / Port Everglades Expressway
Keep slight right at fork onto I 595 / Port Everglades Expressway toward SR 869 Toll North, I 595 East: Coral Springs, Fort Lauderdale
Highway fork - watch signs carefully. Lane positioning matters here. Multiple destination signs - pick the right one
Use the straight / slight right lanes.
Exit 19
Toward SR 869 Toll North, I 595 East: Coral Spr...
8
239.5 mi into trip|~4h 21m in
Take the exit toward US 441: Orlando, Miami, Florida's Turnpike
Exit ramp - move to the correct lane early. Lane positioning matters here. Multiple destination signs - pick the right one
Use the slight right lane.
Exit 8; 9A-B
Toward US 441: Orlando, Miami, Florida's Turnpi...
7
240 mi into trip|~4h 22m in
Take the ramp toward Florida's Turnpike, Miami South, Orlando North
Lane positioning matters here. Multiple destination signs - pick the right one
Use the straight / right lanes.
Exit 8
Toward Florida's Turnpike, Miami South, Orlando...
8
240.4 mi into trip|~4h 23m in
Keep slight left at fork toward Miami, Florida's Turnpike
Highway fork - watch signs carefully. Lane positioning matters here. Multiple destination signs - pick the right one
Use the straight / slight right lanes.
Toward Miami, Florida's Turnpike
8
264.2 mi into trip|~4h 54m in
Take the exit toward Rickenbacker Causeway, Key Biscayne
Exit ramp - move to the correct lane early. Lane positioning matters here. Multiple destination signs - pick the right one
Use the slight right lane.
Exit 1A
Toward Rickenbacker Causeway, Key Biscayne
Fuel & Cost
Regular Gas
$43.57 one way
$87.15 round trip
$4.08/gal25.4 MPG avg95 kg CO2
Fuel Type
$/gal
One Way
Round Trip
midgrade
$4.46
$47.53
$95.06
premium
$4.78
$51.02
$102.04
diesel
$6.28
$66.96
$133.92
Estimated Tolls: $1.67
Sunshine Skyway Bridge
(13.4 mi)$0.94
Florida's Turnpike
(10.4 mi)$0.73
Toll estimates based on average 2024-2025 rates. EZ-Pass/SunPass discounts may lower the actual cost.
Estimated Trip Cost (one way, 1 person)
Fuel
$44
Tolls
$2
Meals
$25–$50
Total
$70–$95
Rough estimate based on US averages. Hotel $80–$140/night, meals $25–$50/day.
Estimated CO2 emission: 94.8 kg one way.
Prices: EIA weekly data, 2026-10-19.
Driving Electric?
About $28 in charging
· 1 stop
· 66% less CO2
Vehicle Type
kWh
Stops
DC Fast
Home Charge
Average EV
81.3
1
$28.46
$13.01
Efficient EV
67.8
0
$23.71
$10.84
EV Truck/SUV
108.4
1
$37.94
$17.34
Gas CO2
95 kg
EV CO2
32 kg (66% less)
Plan for 1 charging stop. A 30-minute DC fast charge mid-route should be enough to complete the trip comfortably.
DC fast charging avg $0.35/kWh. Home charging avg $0.16/kWh. US grid CO2: 0.39 kg/kWh.
Travel Intel
Current conditions at both ends of the drive.
Forecast as of Oct 19, 2026
Origin
St. Petersburg, FL
Night
in St. Petersburg on Thursday
Local time
9:39 PM
EDT
Current temp
82°F
Sunny
NE 12 to 16 mph2% chanceLive forecast
Rip Current Statement
Rip Current Statement issued October 19 at 2:34AM EDT until October 22 at 4:00AM EDT by NWS Melbourne FL
Rip Current Statement
Rip Current Statement issued October 19 at 2:26AM EDT until October 22 at 4:00AM EDT by NWS Jacksonville FL
Destination
Key Biscayne, FL
Night
in Key Biscayne on Thursday
Local time
9:39 PM
EDT
Current temp
84°F
Mostly Sunny
NE 23 to 26 mph13% chanceLive forecast
Rip Current Statement
Rip Current Statement issued October 19 at 2:34AM EDT until October 22 at 4:00AM EDT by NWS Melbourne FL
Rip Current Statement
Rip Current Statement issued October 19 at 2:26AM EDT until October 22 at 4:00AM EDT by NWS Jacksonville FL
73°F
Golden Gate, FL
136 mi in
Seasonal Notes
Summer travel usually means heavier construction, hotter rest stops, and busier weekend traffic around major cities.
Winter travel shortens daylight, so a route that looks manageable on paper can feel much longer after dark.
Holiday weekends tend to make both departure and arrival windows slower than the raw route time suggests.
Time zone
Same local time
Origin and destination are on the same clock, so arrival timing is easier to judge at a glance.
Temperature spread
2 degrees warmer at arrival
A meaningful temperature swing is a good cue to rethink layers, water, and how soon you want to arrive.
Road read
5h 8m on the road
An early start around 7-8 AM gets you there with plenty of daylight left.
Weather data from the National Weather Service. Conditions may change; check closer to your travel date.
National Parks Near This Route
Worth a detour if your schedule allows.
De Soto National Memorial
National Memorial
In May 1539, Conquistador Hernando de Soto’s army of soldiers, hired mercenaries, craftsmen, and clergy made landfall in Tampa Bay. They were met with fierce resistance of indigenous people protecting...
7 mi from route
~18 min detour
Free
near mile 18.7
Within sight of Miami, yet worlds away, Biscayne protects a rare combination of aquamarine waters, emerald islands, and fish-bejeweled coral reefs. Evidence of 10,000 years of human history is here to...
14 mi from route
~36 min detour
Free
near mile 271
Park data from the National Park Service API. Alerts update every 2 hours.
More Details
What kind of drive is this?
This drive is predominantly on surface roads, with 0% highway travel. You'll encounter numerous intersections and traffic signals as you navigate through towns and cities for the entire 271 miles. The longest stretch without a significant break in surface road conditions is not specified, but expect consistent urban and suburban driving patterns. Be prepared for frequent stops and starts due to the nature of surface street navigation.
91% highway — fuel and pacing are the main things to plan.
29 navigation steps total — most of the decisions cluster near the start and finish.
Longest single stretch: 209.3 mi on I 75.
How Hard Is This Drive?
10/10
This is a straightforward highway drive that stays mostly on I 75 and Sunshine Skyway Bridge. This route has several spots where lane changes, forks, or exits need your full attention. The trickiest moment comes around 230.4 miles in near I 595 / Port Everglades Expressway.
Driving Effort10/10
High effort - long or complex enough to need steady focus all day
Balances navigation complexity with total wheel time.
This is a demanding drive. With 22 significant decision points across 271 miles, you will need to stay alert - especially through interchange areas and urban stretches. Consider splitting it into segments if you are not comfortable with fast highway navigation.
Where does it get tricky?
The main spots that need attention: at 230.4 miles (I 595 / Port Everglades Expressway): Highway fork - watch signs carefully. Lane positioning matters here. Multiple destination signs - pick the right one; at 239.5 miles: Exit ramp - move to the correct lane early. Lane positioning matters here. Multiple destination signs - pick the right one; at 240 miles: Lane positioning matters here. Multiple destination signs - pick the right one.
Elevation Profile
Mostly flat terrain
43 ft3 ft
Total Climb
46 ft
Total Descent
85 ft
Highest Point
43 ft
Elevation Range
39 ft
Towns Mentioned on Route Signs
Based on OSRM destination-sign hints, not a full list of every settlement the road passes.
Between St. Petersburg, FL and Key Biscayne, FL, road signs point toward Fort Lauderdale, Miami, Florida's Turnpike, Orlando, Miami South and Orlando North - among others.
Saint Petersburg sits at the base of the Tampa Bay peninsula in Pinellas County, Florida, and enjoys a more subdued social atmosphere than its larger cousin, Tampa. The city has tried to characterize the downtown as an arts and entertainments destination and you will find no shortage of arts and crafts stores, galleries, and museums along with cafes and boutique food shops all within a couple blocks of the Tampa Bay waterfront. With water on three sides of the city, St. Pete is a superb location for fishing, sailing, and wandering beaches.
Top landmarks
•Salvador Dalí Museum — art museum in St. Petersburg, Florida, United States
•Vinoy Park Hotel — historic hotel in St. Petersburg, Florida, USA
•Museum of Fine Arts, St. Petersburg, Florida, USA — museum in St. Petersburg, Florida
Key Biscayne refers to both a tropical island just southeast of Miami and a village on that island. The Village of Key Biscayne, incorporated on June 18, 1991, is in the center of the four-mile-long, two-mile-wide barrier island between the Atlantic Ocean and Biscayne Bay. The wonderful tropical island is very quiet and mostly residential. Key Biscayne Island, which is south of South Beach, is the first island of the Florida Keys. Beaches are spectacular, the landscaping is lush and waterfront activities are plenty. Some consider it the best area to feel like you are in the islands while being in Miami.
Top landmarks
•Cape Florida Light — lighthouse in Florida, United States
Doable as a same-day drive at 5h 8m. Total distance: 271 miles.
Family Friendly
Moderate complexity with 1 natural rest stops along the way.
Solo Traveler
5h 8m drive, comfortable solo distance.
First-Time Driver
Mostly highway driving (91%). Some complex stretches to watch for.
Frequently Asked Questions
The longest stretch is about 209.3 miles on I 75. The full list of main roads is in the Roads section above.
Expect about $1.67 in tolls one way, starting with Sunshine Skyway Bridge. Most Northeast and Midwest toll agencies accept E-ZPass; in the West and Texas, transponders like TxTag or FasTrak apply. If you do not have a transponder, cashless tolling plates will mail a bill to the vehicle's registered address — usually with a surcharge, so a rental-car toll pass is often cheaper than paying by mail.
Yes — we found about 15 rest areas or service plazas within a short detour of the route (from OpenStreetMap). See the Rest Stops tab under Nearby Places for locations and mile markers. Plan to stretch, use the bathroom, and top off fluids every 2–3 hours on longer drives.
It helps. This route has a higher-than-average number of complex decision points, which get harder in the dark. If the last hour of the trip is on surface roads or mountain grades, aim to arrive at Key Biscayne, FL before sunset when you can. Check the Trip Plan for departure windows that land you in daylight.
Only with planning. This is a long drive for kids — consider splitting it into two days rather than pushing through. Plan at least 1 meaningful breaks. There are 15 rest areas along the route for bathroom stops.
The main spots that need attention: at 230.4 miles (I 595 / Port Everglades Expressway): Highway fork - watch signs carefully. Lane positioning matters here. Multiple destination signs - pick the right one; at 239.5 miles: Exit ramp - move to the correct lane early. Lane positioning matters here. Multiple destination signs - pick the right one; at 240 miles: Lane positioning matters here. Multiple destination signs - pick the right one.
Yes — De Soto National Memorial and Biscayne National Park. See the National Parks section for detour distances and tips on detours.
Not recommended in a single day. At 5.1 hours each way, a round trip means 10.3 hours of driving — that is an unsafe level of fatigue for most drivers. Plan at least one night at Key Biscayne, FL before the return drive.
