San Patricio County Southbound Rest Area
0 mi from route
Trip from Portland, 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
2h 37m
Distance
150.7 mi
243 km
Drive Score
8/10
Great drive
Same Day?
Yes, doable
Fuel Cost
$23
one way
EV Charging
Unknown
Best Time to Leave
4 AM
2h 27m
★
6 AM
2h 37m
8 AM
2h 58m
10 AM
2h 45m
12 PM
2h 43m
3 PM
2h 46m
5 PM
2h 57m
8 PM
2h 31m
Estimated drive times based on typical traffic patterns. Actual times may vary with weather, construction, and real-time conditions.
Portland, TX
Thomas balabaud
San Antonio, TX
Wikimedia Commons
Trip Overview
Portland, TX to San Antonio, TX is 150.7 miles and takes about 2h 37m via I 37 and US 181, with a fuel budget near $23 and enough daylight to finish in a day. This trip stays within the Great Plains region, offering a straightforward drive across Texas. Given its relatively short distance and mostly highway profile, it's an easy one-day excursion. You'll spend most of your time on the interstate, making it a predictable and efficient way to get from point A to point B. Plan for a smooth and uncomplicated transit.
Trip Pace
Same-day drive is realistic
A same-day return is realistic if you keep stops short.
Break Rhythm
1 planned break
A short stop every 2 to 3 hours is enough for this drive.
Midpoint
75.4 miles from Portland, TX
A natural place for your longest stop of the day , about 1h 19m into the drive .
Main Roads
| Road | Distance | Duration |
|---|---|---|
| I 37 | 139.3 mi | 2h 21m |
| US 181 | 7 mi | 7m |
| East Commerce Street | 0.9 mi | 1m |
| US Highway 181 | 0.5 mi | <1m |
| Military Plaza | <0.1 mi | <1m |
| Interstate 37 South | <0.1 mi | <1m |
| Dolorosa Street | <0.1 mi | <1m |
Longest stretch:
I 37
— 139.3 mi, about 2h 21m
Turn-by-Turn Driving Directions
Step-by-step road directions between Portland, TX and San Antonio, TX.
1
Start on this road
0.1 mi
·
16 sec
·
this road
Toward Wildcat Drive
2
Turn straight onto US Highway 181
0.2 mi
·
22 sec
·
US Highway 181
3
Continue on US Highway 181
0.3 mi
·
36 sec
·
US Highway 181
4
Take the ramp
0.3 mi
·
34 sec
5
Merge onto US 181; TX 35
7.0 mi
·
7 min
·
US 181; TX 35
6
Take the exit
0.8 mi
·
1 min
7
Keep slight left at fork
0.1 mi
·
16 sec
8
Merge onto I 37
15 mi
·
15 min
·
I 37
9
Keep slight left at fork
1.3 mi
·
1 min
10
Continue on I 37
124 mi
·
2 hr 5 min
·
I 37
Use the straight / slight right lanes.
11
Take the exit
0.3 mi
·
33 sec
Exit 141
Toward Commerce Street, Downtown, The Alamo
Use the straight / slight right lanes.
12
Turn straight onto Interstate 37 South
380 ft
·
11 sec
·
Interstate 37 South
13
Turn left onto East Commerce Street
0.9 mi
·
1 min
·
East Commerce Street
14
Turn left onto Military Plaza
392 ft
·
15 sec
·
Military Plaza
15
Turn left onto Dolorosa Street
327 ft
·
8 sec
·
Dolorosa Street
16
Arrive at destination
Dolorosa Street
Trip Plan
With a drive time under three hours, this route is best tackled in a single day, allowing for flexibility in your departure. Leaving in the morning will give you ample daylight to complete the 150.7-mile trip and arrive in San Antonio with time to spare. The estimated fuel cost is around $23, so ensure your tank is full before you depart Portland, TX. While there's only one recommended stop, you can easily extend or shorten your travel time by adding or skipping breaks, given the short overall duration. Keep an eye on the I 37 corridor for potential traffic as you near San Antonio.
Morning Departure
Leave by 9 AM and you'll arrive before lunch.
Evening Departure
Even a 4 PM departure gets you there before dark in summer.
You can normally do this drive in one day.
Plan roughly 1 meaningful break for fuel, food, and rest.
The halfway point lands around 75.4 miles from Portland, TX, or about 1h 19m into the drive.
The longest continuous stretch on this route runs about 139.3 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 33 miles or 36m in
Use this first pause for coffee, a restroom break, and a quick traffic check ahead.
Halfway reset
Around 75.4 miles or 1h 19m in
This is the best place for your longest stop, a real meal, and a full fuel check.
Final approach
Final hour starts around 2h 8m
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 Portland, 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 Portland, TX
This is one driving day of about 150.7 miles and 2h 37m.
Your first comfortable stop window is around 33 miles from Portland, 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 139.3 miles.
Where to Stop
Rest stops, refuel points, and overnight suggestions along this route.
Mid-route town
Meal stop
75 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 33 miles helps settle the day before fatigue starts building.
Meal break
The midpoint is around 75.4 miles from Portland, 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 139.3 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.
Parking Area
0 mi from route
Picnic Area
0 mi from route
Love's Travel Stop
0.1 mi from route
Picnic Area
0.1 mi from route
Flying J Travel Center
0.1 mi from route
San Patricio County Northbound Rest Area
0.1 mi from route
Live Oak County Southbound Rest Area
0.1 mi from route
Picnic Area
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
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 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 websiteSEA LIFE San Antonio
4.1
★ ★ ★ ★ ☆
Near the end, right off the route
Home stretch
0.4 mi from route
~1 min detour
San Antonio, Texas
Hours: 10 am–5 pm
+12106101160
Visit websiteSan Antonio River Lock & Dam
4.7
★ ★ ★ ★ ★
Near the end, right off the route
Home stretch
0.8 mi from route
~2 min detour
San Antonio, Texas
Hours: 9 am–10 pm
+12102271373
Visit websitePlace data sourced from public business listings. Hours and availability may vary.
Heads-up: tricky spots
5 of 95 decision points cluster between mile 0.6 and 150.6 — GPS handles the exact turns, but know they're coming. Your lane choice matters more than the turn itself.
3
0.6 mi into trip
|
~1m in
Take the ramp
Navigation decision point
4
8.7 mi into trip
|
~11m in
Keep slight left at fork
Highway fork - watch signs carefully
4
24.2 mi into trip
|
~27m in
Keep slight left at fork
Highway fork - watch signs carefully
8
149.3 mi into trip
|
~2h 34m 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
5
150.6 mi into trip
|
~2h 37m in
|
Dolorosa Street
Turn left onto Dolorosa Street
Navigation decision point
Fuel & Cost
Regular Gas
$22.77 one way
$45.54 round trip
$3.84/gal
25.4 MPG avg
53 kg CO2
| Fuel Type | $/gal | One Way | Round Trip |
|---|---|---|---|
| midgrade | $4.20 | $24.92 | $49.85 |
| premium | $4.54 | $26.91 | $53.81 |
| diesel | $5.61 | $33.27 | $66.55 |
No toll roads detected on this route.
Estimated Trip Cost (one way, 1 person)
Fuel
$23
Meals
$25–$50
Total
$48–$73
Rough estimate based on US averages. Hotel $80–$140/night, meals $25–$50/day.
Estimated CO2 emission: 52.7 kg one way. Prices: EIA weekly data, 2026-04-13.
Driving Electric?
About $16 in charging · 0 stops · 66% less CO2
| Vehicle Type | kWh | Stops | DC Fast | Home Charge |
|---|---|---|---|---|
| Average EV | 45.2 | 0 | $15.82 | $7.23 |
| Efficient EV | 37.7 | 0 | $13.19 | $6.03 |
| EV Truck/SUV | 60.3 | 0 | $21.10 | $9.64 |
Gas CO2
53 kg
EV CO2
18 kg (66% less)
This trip is well within single-charge range for most EVs. No charging stops needed if you start fully charged.
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
Portland, TX
Morning in Portland on Tuesday
Local time
9:08 AM
CDT
Current temp
76°F
Unavailable
Live forecast
Destination
San Antonio, TX
Morning in San Antonio on Tuesday
Local time
9:08 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
6 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
2h 37m on the road
Use the two city cards together: check the sky where you start, then compare it with the local time and temperature at arrival.
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.
San Antonio Missions National Historical Park
National Historical Park
Welcome to San Antonio Missions, a National Park Service site and the only UNESCO World Heritage Site in Texas. Each mission in the park is a center of community and has been since the early 1700s. Th...
2 mi from route
~4 min detour
Free
near mile 140.3
View on nps.gov
Park data from the National Park Service API. Alerts update every 2 hours.
What kind of drive is this?
This drive is 97% highway, meaning you'll spend the vast majority of your time on high-speed roads. The longest stretch without significant interruption is 139.3 miles on I 37. You'll transition from interstate cruising to surface streets, specifically East Commerce Street, as you approach San Antonio. Expect a lot of exits and potential for merging traffic as you get closer to the city.
97% highway — fuel and pacing are the main things to plan.
16 navigation steps total — most of the decisions cluster near the start and finish.
Longest single stretch: 139.3 mi on I 37.
How Hard Is This Drive?
5/10
This is a straightforward highway drive that stays mostly on I 37 and US 181. You will hit about 9 points where you need to pay attention to lane position or signs. The trickiest moment comes around 0.6 miles in.
Driving Effort
5/10
Moderate - straightforward overall, but long enough or busy enough to require pacing
Balances navigation complexity with total wheel time.
This drive requires moderate attention. Across 150.7 miles you will encounter 9 spots where lane choice or exit timing matters. Not difficult for experienced highway drivers, but worth previewing the tricky sections before you go.
Where does it get tricky?
The main spots that need attention: at 0.6 miles: Navigation decision point; at 8.7 miles: Highway fork - watch signs carefully; at 24.2 miles: Highway fork - watch signs carefully.
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 2h 37m. Total distance: 150.7 miles.
Family Friendly
Moderate complexity with 1 natural rest stops along the way.
Solo Traveler
2h 37m drive, comfortable solo distance.
First-Time Driver
Mostly highway driving (97%). Some complex stretches to watch for.
Frequently Asked Questions
The longest stretch is about 139.3 miles on I 37. The full list of main roads is in the Roads section above.
Yes — we found about 12 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.
Yes, with realistic expectations. Build in a stop roughly every 2 hours, have snacks and activities ready, and check the Nearby Places tabs for kid-friendly stops along the way.
The main spots that need attention: at 0.6 miles: Navigation decision point; at 8.7 miles: Highway fork - watch signs carefully; at 24.2 miles: Highway fork - watch signs carefully.
Yes — San Antonio Missions National Historical Park. See the National Parks section for detour distances and tips on detours.
Yes. A round trip is manageable in a single day if you plan a break at San Antonio, TX before heading back.
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, and NPS for national parks. See our methodology for refresh cadence and limitations.
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