Rest Area
0 mi from route
Trip from Port Isabel, TX to San Antonio, TX
Pin this tripCompiled and reviewed by the US Trip Planner planning team at COD Solutions Oy · Last reviewed Apr 21, 2026 · Editorial standards
Drive Time
5h 29m
Distance
289.6 mi
466 km
Drive Score
8/10
Great drive
Same Day?
Yes, doable
Fuel Cost
$44
one way
EV Charging
Unknown
Best Time to Leave
4 AM
5h 16m
★
6 AM
5h 30m
8 AM
5h 56m
10 AM
5h 39m
12 PM
5h 36m
3 PM
5h 40m
5 PM
5h 55m
8 PM
5h 22m
Estimated drive times based on typical traffic patterns. Actual times may vary with weather, construction, and real-time conditions.
Port Isabel, TX
Griffin Wooldridge
San Antonio, TX
Wikimedia Commons
Trip Overview
Port Isabel to San Antonio is 289.6 miles and takes about 5h 29m via US 281 and U.S. Highway 77, with a fuel budget near $44 and enough daylight to finish in a day. This trip stays within Texas, moving from the coastal region near the Great Plains to the interior Great Plains. The route is predominantly highway driving, making it a straightforward, efficient trip. You'll find it's a solid choice for a single-day drive, especially if you're looking to cover ground without too many detours.
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
144.8 miles from Port Isabel, TX
A natural place for your longest stop of the day , about 2h 46m into the drive .
Main Roads
| Road | Distance | Duration |
|---|---|---|
| US 281 | 123.2 mi | 2h 13m |
| U.S. Highway 77 | 102 mi | 1h 53m |
| Nueces Street | 14.7 mi | 18m |
| West King Avenue | 14.5 mi | 17m |
| TX 48 | 14.1 mi | 15m |
| South 6th Street | 4.4 mi | 7m |
| State Highway 550 | 3.6 mi | 3m |
| Interstate 169 | 3.6 mi | 3m |
Longest stretch:
US 281
— 123.2 mi, about 2h 13m
Turn-by-Turn Driving Directions
Step-by-step road directions between Port Isabel, TX and San Antonio, TX.
1
Start on South Musina Street
0.2 mi
·
33 sec
·
South Musina Street
2
Turn left onto TX 100
0.1 mi
·
23 sec
·
West Queen Isabella Boulevard
3
Turn straight onto TX 100
1.0 mi
·
2 min
·
State Highway 100
Use the left lane.
4
Turn left onto TX 48
14 mi
·
15 min
·
TX 48
Use the left lane.
5
Take the exit
0.2 mi
·
22 sec
Toward TX 550
Use the straight / slight right lanes.
6
Keep slight right at fork
47 ft
·
1 sec
Toward TX 550
Use the straight / left / right lanes.
7
Turn right onto TX 550 Toll
3.6 mi
·
3 min
·
State Highway 550
8
Continue on FM 511
1.9 mi
·
2 min
·
FM 511
9
Continue on I 169; TX 550 Toll
0.9 mi
·
58 sec
·
I-169, TX 550 Toll
10
Continue on I 169; TX 550 Toll
3.6 mi
·
3 min
·
Interstate 169
11
Merge onto I 69E; US 77; US 83
2.2 mi
·
2 min
·
North Expressway
12
Continue on I 69E; US 77; US 83
102 mi
·
1 hr 53 min
·
U.S. Highway 77
Use the straight / slight right lanes.
13
Keep slight right at fork
0.1 mi
·
8 sec
14
Keep slight right at fork
0.7 mi
·
1 min
15
Turn left onto FM 772
0.2 mi
·
17 sec
·
FM 772
16
Turn straight onto US 77 Business
4.4 mi
·
7 min
·
South 6th Street
17
Turn left onto TX 141
14 mi
·
17 min
·
West King Avenue
18
Take the ramp
0.6 mi
·
1 min
19
Merge onto US 281
54 mi
·
1 hr 1 min
·
US 281
20
Keep slight left at fork onto US 281
15 mi
·
18 min
·
Nueces Street
21
Continue on US 281
0.2 mi
·
15 sec
·
US 281
22
Take the exit onto US 281
69 mi
·
1 hr 11 min
·
US 281
Use the straight / slight right lanes.
23
Take the exit
0.3 mi
·
33 sec
Exit 141
Toward Commerce Street, Downtown, The Alamo
Use the straight / slight right lanes.
24
Turn straight onto Interstate 37 South
380 ft
·
11 sec
·
Interstate 37 South
25
Turn left onto East Commerce Street
0.9 mi
·
1 min
·
East Commerce Street
26
Turn left onto Military Plaza
392 ft
·
15 sec
·
Military Plaza
27
Turn left onto Dolorosa Street
327 ft
·
8 sec
·
Dolorosa Street
28
Arrive at destination
Dolorosa Street
Trip Plan
Given the 5-hour 29-minute estimated drive time and a fuel cost around $44, this route is easily manageable in a single day. Leaving Port Isabel in the morning will give you ample time to reach San Antonio before evening, even with a brief stop. The route has only one recommended stop, suggesting you can be flexible with your timing. Keep an eye on your fuel levels, particularly during the 123.2-mile stretch on US 281, as services can be more spread out in some sections.
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 144.8 miles from Port Isabel, TX, or about 2h 46m into the drive.
The longest continuous stretch on this route runs about 123.2 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 64 miles or 1h 12m in
Use this first pause for coffee, a restroom break, and a quick traffic check ahead.
Halfway reset
Around 144.8 miles or 2h 46m 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 34m
Traffic, exits, and arrival timing usually matter more near San Antonio, TX than in the middle of the route.
Before You Leave
+
Open the route before leaving Port Isabel, 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 Port Isabel, TX
This is one driving day of about 289.6 miles and 5h 29m.
Your first comfortable stop window is around 64 miles from Port Isabel, 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 US 281 for about 123.2 miles.
Where to Stop
Rest stops, refuel points, and overnight suggestions along this route.
Mid-route town
Meal stop
145 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 64 miles helps settle the day before fatigue starts building.
Meal break
The midpoint is around 144.8 miles from Port Isabel, TX, which is a good place for a longer meal and fuel stop.
Before the longest stretch
Fuel checkTop up before US 281 if your tank is already low. That segment runs about 123.2 miles.
These stop ideas are pacing suggestions — the exact town or exit can change with traffic, hotel plans, and fuel range.
Stops Along Your Drive
Picked by where they fit in your drive — first break, midpoint reset, final stretch.
Picnic Area
0 mi from route
Love's Travel Stop
0.1 mi from route
Kenedy County Rest Area
0.1 mi from route
Rest Area
0.1 mi from route
Texas Travel Information Center at Harlingen
0.1 mi from route
Live Oak County Southbound Rest Area
0.1 mi from route
Picnic Area
0.1 mi from route
Love's Travel Stop
0.1 mi from route
Road Ranger
0.1 mi from route
Service Plaza
0.1 mi from route
QuikTrip
0.1 mi from route
Pilot Travel Center
0.2 mi from route
Live Oak County Northbound Rest Area
0.3 mi from route
Love's Travel Stop
0.9 mi from route
Love's Travel Stop
1.8 mi from route
Spanish Governor's Palace
4.5
★ ★ ★ ★ ★
Near the end, right off the route
Home stretch
0.1 mi from route
San Antonio, Texas
Hours: 9 am–5 pm
+12102077527
Visit websiteGO RIO San Antonio River Cruises
4.6
★ ★ ★ ★ ★
Near the end, right off the route
Home stretch
0.4 mi from route
~1 min detour
San Antonio, Texas
Hours: 10 am–10 pm
+12102274746
Visit websiteSan Antonio | The Saga
4.5
★ ★ ★ ★ ★
Near the end, right off the route
Home stretch
0 mi from route
San Antonio, Texas
Hours: 9–9:30 pm
+12102259800
Visit websiteHemisfair
4.7
★ ★ ★ ★ ★
Near the end, right off the route
Home stretch
0.5 mi from route
~1 min detour
San Antonio, Texas
Hours: 5 am–12 pm
+12107094750
Visit websitePirate's Landing Fishing Pier
4.5
★ ★ ★ ★ ★
Near the start, right off the route
0.4 mi from route
~1 min detour
Port Isabel, Texas
Hours: Open 24 hours
+19569437437
Visit websiteSan Antonio Fire Museum
4.9
★ ★ ★ ★ ★
Near the end, right off the route
Home stretch
0.6 mi from route
~1 min detour
San Antonio, Texas
Hours: 10 am–3:30 pm
+12103907236
Visit websiteThe Amazing Mirror Maze
4.4
★ ★ ★ ★ ☆
Near the end, right off the route
Home stretch
0.4 mi from route
~1 min detour
San Antonio, Texas
Hours: 10:30 am–8 pm
+12102242288
Visit websitePort Isabel Historical Museum
4.5
★ ★ ★ ★ ★
Near the start, right off the route
0.2 mi from route
~1 min detour
Port Isabel, Texas
Hours: 10 am–4 pm
+19569437602
Visit websitePlace data sourced from public business listings. Hours and availability may vary.
Heads-up: tricky spots
5 of 175 decision points cluster between mile 1.4 and 288.2 — GPS handles the exact turns, but know they're coming. Your lane choice matters more than the turn itself.
5
1.4 mi into trip
|
~3m in
|
TX 48
Turn left onto TX 48
Lane positioning matters here
Use the left lane.
6
15.5 mi into trip
|
~18m in
Take the exit toward TX 550
Exit ramp - move to the correct lane early. Lane positioning matters here
Use the straight / slight right lanes.
Toward TX 550
8
15.6 mi into trip
|
~19m in
Keep slight right at fork toward TX 550
Highway fork - watch signs carefully. Lane positioning matters here
Use the straight / left / right lanes.
Toward TX 550
5
219.5 mi into trip
|
~4h 15m in
|
US 281
Take the exit onto US 281
Exit ramp - move to the correct lane early. Lane positioning matters here
Use the straight / slight right lanes.
8
288.2 mi into trip
|
~5h 26m in
Take the exit toward Commerce Street, Downtown, The Alamo
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 141
Toward Commerce Street, Downtown, The Alamo
Fuel & Cost
Regular Gas
$43.76 one way
$87.52 round trip
$3.84/gal
25.4 MPG avg
101 kg CO2
| Fuel Type | $/gal | One Way | Round Trip |
|---|---|---|---|
| midgrade | $4.20 | $47.90 | $95.80 |
| premium | $4.54 | $51.71 | $103.41 |
| diesel | $5.61 | $63.94 | $127.88 |
No toll roads detected on this route.
Estimated Trip Cost (one way, 1 person)
Fuel
$44
Meals
$25–$50
Total
$69–$94
Rough estimate based on US averages. Hotel $80–$140/night, meals $25–$50/day.
Estimated CO2 emission: 101.3 kg one way. Prices: EIA weekly data, 2026-04-13.
Driving Electric?
About $30 in charging · 1 stop · 66% less CO2
| Vehicle Type | kWh | Stops | DC Fast | Home Charge |
|---|---|---|---|---|
| Average EV | 86.9 | 1 | $30.41 | $13.90 |
| Efficient EV | 72.4 | 0 | $25.34 | $11.58 |
| EV Truck/SUV | 115.8 | 1 | $40.54 | $18.53 |
Gas CO2
101 kg
EV CO2
34 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.
Origin
Port Isabel, TX
Morning in Port Isabel on Tuesday
Local time
7:25 AM
CDT
Current temp
86°F
Unavailable
Live forecast
Destination
San Antonio, TX
Morning in San Antonio on Tuesday
Local time
7:25 AM
CDT
Current temp
70°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
16 degrees cooler at arrival
A meaningful temperature swing is a good cue to rethink layers, water, and how soon you want to arrive.
Road read
5h 29m 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.
What kind of drive is this?
This drive is mostly highway, with 87% of the route on major roads. The longest continuous stretch you'll encounter is 123.2 miles on US 281. You'll transition from highway to surface streets like Nueces Street as you approach your destination. Expect a consistent cruising feel for most of the 5.5-hour drive.
87% highway — fuel and pacing are the main things to plan.
28 navigation steps total — most of the decisions cluster near the start and finish.
Longest single stretch: 123.2 mi on US 281.
How Hard Is This Drive?
9/10
This is a straightforward highway drive that stays mostly on US 281 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 1.4 miles in near TX 48.
Driving Effort
9/10
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 17 significant decision points across 289.6 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 1.4 miles (TX 48): Lane positioning matters here; at 15.5 miles: Exit ramp - move to the correct lane early. Lane positioning matters here; at 15.6 miles: Highway fork - watch signs carefully. Lane positioning matters here.
About the Cities
Arriving in San Antonio, TX
Full guide →Founded 1718
San Antonio is the second largest city in the state of Texas and the 7th largest in the United States. It's the 24th largest metropolitan area in the country. Visited by more than 31 million annual visitors, San Antonio is a beautiful city at the axis of three different geological terrains: Hill Country, South Texas Plains and Prairie and Lakes. There's a lot to do in this city: fine art museums, historical missions and plenty of amusement parks in addition to great dining and lots of drinking. The culture and people are vibrant and interesting. San Antonio's downtown is one of the most lively in the nation.
Top landmarks
- • Alamo Mission in San Antonio — historic place in San Antonio, Bexar County, Texas
- • San Antonio Missions National Historical Park — historic district in San Antonio, Bexar County, Texas
- • Fort Sam Houston — military base in San Antonio, 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 5h 29m. Total distance: 289.6 miles.
Family Friendly
Moderate complexity with 1 natural rest stops along the way.
Solo Traveler
5h 29m drive, comfortable solo distance.
First-Time Driver
Mostly highway driving (87%). Some complex stretches to watch for.
Frequently Asked Questions
The longest stretch is about 123.2 miles on US 281. The full list of main roads is in the Roads section above.
Yes — we found about 16 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 San Antonio, 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. There are 16 rest areas along the route for bathroom stops.
The main spots that need attention: at 1.4 miles (TX 48): Lane positioning matters here; at 15.5 miles: Exit ramp - move to the correct lane early. Lane positioning matters here; at 15.6 miles: Highway fork - watch signs carefully. Lane positioning matters here.
Not recommended in a single day. At 5.5 hours each way, a round trip means 11.0 hours of driving — that is an unsafe level of fatigue for most drivers. Plan at least one night at San Antonio, 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, and EIA for fuel prices. See our methodology for refresh cadence and limitations.
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