Origin
Austin, TX
Morning in Austin on Friday
Local time
6:55 AM
CDT
Current temp
77°F
Unavailable
Live forecast
Trip from Austin, TX to Port Isabel, TX
Pin this tripCompiled and reviewed by the US Trip Planner planning team at COD Solutions Oy · Last reviewed Sep 4, 2026 · Editorial standards
Drive Time
6h 35m
Distance
365.7 mi
589 km
Drive Score
9/10
Great drive
Same Day?
Yes, doable
Fuel Cost
$53
one way
EV Charging
Unknown
Best Time to Leave
4 AM
6h 23m
★
6 AM
6h 35m
8 AM
6h 59m
10 AM
6h 44m
12 PM
6h 41m
3 PM
6h 45m
5 PM
6h 58m
8 PM
6h 28m
Estimated drive times based on typical traffic patterns. Actual times may vary with weather, construction, and real-time conditions.
Austin, TX
Wikimedia Commons
Port Isabel, TX
Griffin Wooldridge
Trip Overview
The drive from Austin, TX to Port Isabel, TX covers 365.7 miles and takes about 6h 35m behind the wheel. This route is realistic as a one-day drive if you keep your stops efficient.
The route leans on I 37, U.S. Highway 77, Purple Heart Trail for much of the mileage, and the overall profile is mostly highway. The longest uninterrupted segment is about 118.7 miles on I 37. At current regular gas prices, budget about $53.06 one way before food or hotel costs.
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
182.9 miles from Austin, TX
A natural place for your longest stop of the day , about 3h 13m into the drive .
Main Roads
| Road | Distance | Duration |
|---|---|---|
| I 37 | 118.7 mi | 1h 59m |
| U.S. Highway 77 | 105 mi | 1h 56m |
| Purple Heart Trail | 58.3 mi | 1h 3m |
| I 69E | 31.3 mi | 33m |
| Brownsville-Port Isabel Highway | 14.1 mi | 15m |
| Connally Loop | 11 mi | 12m |
| North Pan Am Expressway | 10 mi | 11m |
| Interstate 169 | 3.7 mi | 3m |
Longest stretch:
I 37
— 118.7 mi, about 1h 59m
Traffic on I-35
Hour-of-day weekday pattern from 28 FHWA count stations on your route.
Peak
2 PM
~4,140 veh/hr typical
Quietest
3 AM
~767 veh/hr
Peak-to-quiet ratio
5.4×
busier at peak than in the quiet hours
12a
6a
noon
6p
11p
Averaged across 101 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 Austin, TX and Port Isabel, TX.
1
Start on East 5th Street
0.5 mi
·
1 min
·
East 5th Street
Use the straight / right lanes.
2
At end of road, turn right onto North Interstate 35
0.4 mi
·
39 sec
·
North Interstate 35
Use the straight / slight left lanes.
3
Take the ramp
0.2 mi
·
21 sec
Toward I 35 South
4
Merge onto I 35; US 290
46 mi
·
50 min
·
Purple Heart Trail
Use the straight / slight right lanes.
5
Continue on I 35
1.7 mi
·
1 min
·
Interstate Highway 35
Use the straight / slight right lanes.
6
Continue on I 35
12 mi
·
12 min
·
Purple Heart Trail
Use the straight / slight right lanes.
7
Continue on I 35
10.0 mi
·
11 min
·
North Pan Am Expressway
Use the straight / slight right lanes.
8
Keep slight right at fork onto I 410
11 mi
·
12 min
·
Connally Loop
Toward I 410 South
Use the straight / slight right lanes.
9
Take the exit
0.2 mi
·
28 sec
Exit 41
Toward I 37, US 281 North: San Antonio, Corpus Christi
Use the straight / slight right lanes.
10
Keep slight left at fork
0.5 mi
·
1 min
Toward I 37 South: Corpus Christi
Use the slight left / slight right lanes.
11
Merge onto I 37
119 mi
·
1 hr 59 min
·
I 37
Use the straight / slight right lanes.
12
Take the exit onto I 69E; US 77
31 mi
·
33 min
·
I 69E; US 77
Toward I 69E, US 77: Kingsville, Brownsville
Use the straight / slight right lanes.
13
Keep slight left at fork onto US 77
61 mi
·
1 hr 9 min
·
U.S. Highway 77
14
Keep slight left at fork onto I 69E; US 77
44 mi
·
46 min
·
U.S. Highway 77
Use the straight / slight right lanes.
15
Continue on I 69E; US 77; US 83
2.1 mi
·
2 min
·
North Expressway
16
Keep slight right at fork onto I 169; TX 550 Toll
3.7 mi
·
3 min
·
Interstate 169
Exit 10B
Toward TX 550 Toll: Port of Brownsville
Use the straight / slight right lanes.
17
Continue on I 169; TX 550 Toll
0.8 mi
·
51 sec
·
I-169, TX 550 Toll
18
Continue on FM 511
2.0 mi
·
2 min
·
FM 511
19
Continue on TX 550 Toll
3.7 mi
·
4 min
·
State Highway 550
20
Turn left
0.2 mi
·
27 sec
Use the left lane.
21
Merge onto TX 48
14 mi
·
15 min
·
Brownsville-Port Isabel Highway
22
Turn right onto TX 100
1.0 mi
·
2 min
·
State Highway 100
23
Turn slight right onto TX 100
0.1 mi
·
24 sec
·
West Queen Isabella Boulevard
24
Turn right onto South Musina Street
0.2 mi
·
24 sec
·
South Musina Street
25
Arrive at destination
South Musina Street
Trip Plan
Morning Departure
Start early — leave by 6-7 AM to arrive at a reasonable hour.
Evening Departure
This is a long drive — plan for a morning departure or consider splitting it into two days.
You can normally do this drive in one day.
Plan roughly 1 meaningful break for fuel, food, and rest.
The halfway point lands around 182.9 miles from Austin, TX, or about 3h 13m into the drive.
The longest continuous stretch on this route runs about 118.7 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 80 miles or 1h 29m in
Use this first pause for coffee, a restroom break, and a quick traffic check ahead.
Halfway reset
Around 182.9 miles or 3h 13m in
This is the best place for your longest stop, a real meal, and a full fuel check.
Final approach
Final hour starts around 5h 28m
Traffic, exits, and arrival timing usually matter more near Port Isabel, TX than in the middle of the route.
Before You Leave
+
Open the route before leaving Austin, TX 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 Austin, TX
This is one driving day of about 365.7 miles and 6h 35m.
Your first comfortable stop window is around 80 miles from Austin, TX.
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 37 for about 118.7 miles.
Where to Stop
Rest stops, refuel points, and overnight suggestions along this route.
Mid-route town
Meal stop
183 mi into the route
Best for: Lunch, fuel, and a longer reset
This sits close to the middle of the route, so it works well for the longest stop of the day.
Pacing Suggestions
Fuel and coffee
A short stop after about 80 miles helps settle the day before fatigue starts building.
Meal break
The midpoint is around 182.9 miles from Austin, TX, which is a good place for a longer meal and fuel stop.
Before the longest stretch
Fuel checkTop up before I 37 if your tank is already low. That segment runs about 118.7 miles.
These stop ideas are pacing suggestions — the exact town or exit can change with traffic, hotel plans, and fuel range.
Heads-up: tricky spots
5 of 165 decision points cluster between mile 0.5 and 339.9 — GPS handles the exact turns, but know they're coming. Your lane choice matters more than the turn itself.
7
0.5 mi into trip
|
~1m in
|
North Interstate 35
At end of road, turn right onto North Interstate 35
Lane positioning matters here
Use the straight / slight left lanes.
7
71.1 mi into trip
|
~1h 18m in
|
I 410 / Connally Loop
Keep slight right at fork onto I 410 / Connally Loop toward I 410 South
Highway fork - watch signs carefully. Lane positioning matters here
Use the straight / slight right lanes.
Toward I 410 South
8
82 mi into trip
|
~1h 31m in
Take the exit toward I 37, US 281 North: San Antonio, Corpus Christi
Exit ramp - move to the correct lane early. Lane positioning matters here. Multiple destination signs - pick the right one
Use the straight / slight right lanes.
Exit 41
Toward I 37, US 281 North: San Antonio, Corpus...
7
82.2 mi into trip
|
~1h 31m in
Keep slight left at fork toward I 37 South: Corpus Christi
Highway fork - watch signs carefully. Lane positioning matters here
Use the slight left / slight right lanes.
Toward I 37 South: Corpus Christi
8
339.9 mi into trip
|
~6h 4m in
|
I 169; TX 550 Toll / Interstate 169
Keep slight right at fork onto I 169; TX 550 Toll / Interstate 169 toward TX 550 Toll: Port of Brownsville
Highway fork - watch signs carefully. Lane positioning matters here
Use the straight / slight right lanes.
Exit 10B
Toward TX 550 Toll: Port of Brownsville
Fuel & Cost
Regular Gas
$53.06 one way
$106.11 round trip
$3.69/gal
25.4 MPG avg
128 kg CO2
| Fuel Type | $/gal | One Way | Round Trip |
|---|---|---|---|
| midgrade | $4.08 | $58.79 | $117.57 |
| premium | $4.43 | $63.81 | $127.62 |
| diesel | $5.60 | $80.61 | $161.22 |
No toll roads detected on this route.
Estimated Trip Cost (one way, 1 person)
Fuel
$53
Meals
$25–$50
Total
$78–$103
Rough estimate based on US averages. Hotel $80–$140/night, meals $25–$50/day.
Estimated CO2 emission: 128 kg one way. Prices: EIA weekly data, 2026-08-31.
Driving Electric?
About $38 in charging · 1 stop · 66% less CO2
| Vehicle Type | kWh | Stops | DC Fast | Home Charge |
|---|---|---|---|---|
| Average EV | 109.7 | 1 | $38.40 | $17.55 |
| Efficient EV | 91.4 | 1 | $32.00 | $14.63 |
| EV Truck/SUV | 146.3 | 1 | $51.20 | $23.40 |
Gas CO2
128 kg
EV CO2
43 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.
Destination
Port Isabel, TX
Morning in Port Isabel on Friday
Local time
6:55 AM
CDT
Current temp
89°F
Unavailable
Live forecast
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
12 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
6h 35m on the road
Start early — leave by 6-7 AM to arrive at a reasonable hour.
Weather data from the National Weather Service. Conditions may change; check closer to your travel date.
What kind of drive is this?
365.7 mi in 6h 35m, mostly highway — 118.7 mi of that is on I 37.
77% highway — fuel and pacing are the main things to plan.
25 navigation steps total — most of the decisions cluster near the start and finish.
Longest single stretch: 118.7 mi on I 37.
How Hard Is This Drive?
8/10
This is a straightforward highway drive that stays mostly on I 37 and U.S. Highway 77. This route has several spots where lane changes, forks, or exits need your full attention. The trickiest moment comes around 0.5 miles in near North Interstate 35.
Driving Effort
8/10
Demanding - plan breaks and stay ahead of the key maneuvers
Balances navigation complexity with total wheel time.
This is a demanding drive. With 16 significant decision points across 365.7 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 0.5 miles (North Interstate 35): Lane positioning matters here; at 71.1 miles (I 410 / Connally Loop): Highway fork - watch signs carefully. Lane positioning matters here; at 82 miles: Exit ramp - move to the correct lane early. Lane positioning matters here. Multiple destination signs - pick the right one.
Elevation Profile
Mostly flat terrain
729 ft
8 ft
Total Climb
258 ft
Total Descent
737 ft
Highest Point
729 ft
~52.2 mi in
Elevation Range
721 ft
Towns Mentioned on Route Signs
Based on OSRM destination-sign hints, not a full list of every settlement the road passes.
Towns Mentioned on Route Signs
Based on OSRM destination-sign hints, not a full list of every settlement the road passes.
Between Austin, TX and Port Isabel, TX, road signs point toward Corpus Christi and Brownsville.
Corpus Christi
82 mi in
|
~1h 31m
Brownsville
201.5 mi in
|
~3h 32m
|
via I 69E; US 77
About the Cities
Starting in Austin, TX
Full guide →“City of the Violet Crown” · Founded 1835
Austin is a city of about 1,054,000 (2026) surpassing Fort Worth to become the 4th most populous city in Texas. It is on the southeast edge of the Hill Country region of Texas, making it the fourth-largest city in the state and the 11th-largest in the country. It is the capital of Texas and a college town, and also a center of an alternative culture away from the major cities on the US coasts, though the city is rapidly gentrifying with its rising popularity. Austin's attitude is commonly emblazoned about town on T-shirts and bumper stickers that read: "Keep Austin Weird." Austin is also marketed as the Live Music Capital of the World due to the large number of venues.
Top landmarks
- • Texas State Capitol — capitol and seat of government of the U.S. state of Texas
- • Lyndon Baines Johnson Library and Museum — presidential library and museum for U.S. President Lyndon B. Johnson in Austin,...
- • Texas State Cemetery — historic cemetery in Austin, Texas, USA
Arriving in Port Isabel, TX
Full guide →The City of Port Isabel, population 6,300 in 2019, is the southernmost city and port on the Texas coast. It is a tourism, retirement, sports fishing and commercial fishing destination and the gateway to South Padre Island.
Top landmarks
- • Point Isabel Lighthouse — structure in Port Isabel, Cameron County, Texas
City content from Wikivoyage (CC BY-SA 4.0) and Wikidata (CC0).
Who Is This Route For?
Weekend Trip
Doable as a same-day drive at 6h 35m. Total distance: 365.7 miles.
Family Friendly
Moderate complexity with 1 natural rest stops along the way.
Solo Traveler
6h 35m drive, plan rest stops for pacing.
Frequently Asked Questions
The longest stretch is about 118.7 miles on I 37. The full list of main roads is in the Roads section above.
We did not find dedicated rest areas on this route. For a drive this long, plan bathroom and stretch breaks around gas stations, fast-food stops, or small-town downtowns — check the Nearby Places section for options.
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 Port Isabel, TX 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. Dedicated rest areas are limited, so plan gas or food stops as your bathroom breaks.
The main spots that need attention: at 0.5 miles (North Interstate 35): Lane positioning matters here; at 71.1 miles (I 410 / Connally Loop): Highway fork - watch signs carefully. Lane positioning matters here; at 82 miles: Exit ramp - move to the correct lane early. Lane positioning matters here. Multiple destination signs - pick the right one.
Not recommended in a single day. At 6.6 hours each way, a round trip means 13.2 hours of driving — that is an unsafe level of fatigue for most drivers. Plan at least one night at Port Isabel, TX before the return drive.
How this page is built
Compiled by the US Trip Planner planning team at COD Solutions Oy from open government datasets — OSRM over OpenStreetMap for geometry, EIA for fuel prices, USGS 3DEP for elevation, and FHWA TMAS for hourly traffic volumes. See our methodology for refresh cadence and limitations.
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