San Leon to San Antonio is 234.6 miles and takes about 4 hours 19 minutes via I 10, with a fuel budget near $37 and enough daylight to finish in a day. This trip stays within the Great Plains region, offering a straightforward drive across Texas. With 97% of the route on highways, expect a consistent pace for most of your travel. It's a practical choice for a single-day trip, allowing you to reach your destination without needing an overnight stay. Consider this a no-fuss option when you need to get from the coast to inland Texas efficiently.
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
117.3 miles from San Leon, TX
A natural place for your longest stop of the day
, about 2h 12m into the drive
.
Main Roads
Road
Distance
Duration
Katy Freeway
174.7 mi
3h 1m
South Gulf Freeway
28.3 mi
32m
I 10
12 mi
12m
FM 517
8.7 mi
14m
East Commerce Street
4.3 mi
7m
Jose Lopez Freeway
1.6 mi
1m
Pine Drive
1.4 mi
2m
Gulf Freeway Frontage Road
1 mi
1m
Longest stretch:
Katy Freeway
— 174.7 mi, about 3h 1m
Traffic on I-10
Hour-of-day weekday pattern from 26 FHWA count stations on your route.
Peak
2 PM
~2,432 veh/hr typical
· worst 3,335
Quietest
2 AM
~346 veh/hr
Peak-to-quiet ratio
7×
busier at peak than in the quiet hours
12a6anoon6p11p
Averaged across 52 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 San Leon, TX and San Antonio, TX.
1
Start on Avenue I
165 ft·9 sec·Avenue I
2
Continue on FM 517
8.7 mi·14 min·FM 517
3
Turn left onto FM 517
0.3 mi·28 sec·Parke Street
4
Turn straight onto FM 517
446 ft·9 sec·Main Street
5
Continue on FM 517
0.3 mi·31 sec·Pine Street
6
Continue on FM 517
1.4 mi·2 min·Pine Drive
7
Turn right onto Gulf Freeway Frontage Road
1.0 mi·1 min·Gulf Freeway Frontage Road
8
Take the ramp
0.2 mi·25 sec
Toward I 45 NorthUse the slight left lane.
9
Merge onto I 45
28 mi·32 min·South Gulf Freeway
Use the straight / slight right lanes.
10
Take the exit
0.1 mi·17 sec
Exit 48BToward I 10 West: San AntonioUse the slight left / straight lanes.
11
Merge onto I 10; US 90
175 mi·3 hr 1 min·Katy Freeway
Use the straight / slight right lanes.
12
Keep slight left at fork onto I 10; US 90; TX 130
12 mi·12 min·I 10; US 90; TX 130
Use the straight / slight right lanes.
13
Keep slight left at fork onto I 10; US 90; TX 130
0.8 mi·51 sec·90th Infantry Division Highway
Use the straight / slight right lanes.
14
Continue on I 10; US 90
1.6 mi·1 min·Jose Lopez Freeway
Use the straight / slight right lanes.
15
Take the exit
0.1 mi·19 sec
Exit 579Toward Commerce Street, Houston StreetUse the straight / slight right lanes.
16
Turn straight onto Interstate 10 East
0.3 mi·38 sec·Interstate 10 East
17
Turn right onto East Houston Street
0.2 mi·20 sec·East Houston Street
18
Turn slight left onto East Commerce Street
4.3 mi·7 min·East Commerce Street
19
Turn left onto Military Plaza
392 ft·15 sec·Military Plaza
20
Turn left onto Dolorosa Street
327 ft·8 sec·Dolorosa Street
21
Arrive at destination
Dolorosa Street
Trip Plan
Given the 4-hour 19-minute drive, leaving San Leon in the morning is ideal to maximize daylight and avoid late-night driving. The route is designed for a single day, so you won't need to break it up, but a brief stop around the halfway point might be welcome. Keep an eye on your fuel gauge, especially during the 174.7-mile stretch on the Katy Freeway, as services can be spaced out. Your estimated fuel cost is around $37, so plan accordingly before you set off. Since it's a relatively short drive, you have flexibility to depart a little later if needed.
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 117.3 miles from San Leon, TX, or about 2h 12m into the drive.
The longest continuous stretch on this route runs about 174.7 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 52 miles or 1h 5m in
Use this first pause for coffee, a restroom break, and a quick traffic check ahead.
Halfway reset
Around 117.3 miles or 2h 12m in
This is the best place for your longest stop, a real meal, and a full fuel check.
Final approach
Final hour starts around 3h 31m
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 San Leon, 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 San Leon, TX
This is one driving day of about 234.6 miles and 4h 19m.
Your first comfortable stop window is around 52 miles from San Leon, 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 Katy Freeway for about 174.7 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 10
5 decision points cluster between mile 11.8 and 229.5 — GPS handles the exact turns, but know they're coming. Your lane choice matters more than the turn itself.
5
11.8 mi into trip|~19m in
Take the ramp toward I 45 North
Lane positioning matters here
Use the slight left lane.
Toward I 45 North
7
40.3 mi into trip|~52m in
Take the exit toward I 10 West: San Antonio
Exit ramp - move to the correct lane early. Lane positioning matters here
Use the slight left / straight lanes.
Exit 48B
Toward I 10 West: San Antonio
6
215.1 mi into trip|~3h 54m in|I 10; US 90; TX 130
Keep slight left at fork onto I 10; US 90; TX 130
Highway fork - watch signs carefully. Lane positioning matters here
Use the straight / slight right lanes.
6
227.2 mi into trip|~4h 7m in|I 10; US 90; TX 130 / 90th Infantry Division Highway
Keep slight left at fork onto I 10; US 90; TX 130 / 90th Infantry Division Highway
Highway fork - watch signs carefully. Lane positioning matters here
Use the straight / slight right lanes.
8
229.5 mi into trip|~4h 10m in
Take the exit toward Commerce Street, Houston Street
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 579
Toward Commerce Street, Houston Street
Fuel & Cost
Regular Gas
$32.13 one way
$64.27 round trip
$3.48/gal25.4 MPG avg82 kg CO2
Fuel Type
$/gal
One Way
Round Trip
midgrade
$3.89
$35.89
$71.78
premium
$4.23
$39.02
$78.05
diesel
$4.80
$44.30
$88.59
No toll roads detected on this route.
Estimated Trip Cost (one way, 1 person)
Fuel
$32
Meals
$25–$50
Total
$57–$82
Rough estimate based on US averages. Hotel $80–$140/night, meals $25–$50/day.
Estimated CO2 emission: 82.1 kg one way.
Prices: EIA weekly data, 2026-07-13.
Driving Electric?
About $25 in charging
· 0 stops
· 67% less CO2
Vehicle Type
kWh
Stops
DC Fast
Home Charge
Average EV
70.4
0
$24.63
$11.26
Efficient EV
58.7
0
$20.53
$9.38
EV Truck/SUV
93.8
1
$32.84
$15.01
Gas CO2
82 kg
EV CO2
27 kg (67% less)
Plan for 0 charging stops, roughly every 270 miles. Allow 25-40 minutes per stop at a DC fast charger.
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 Jul 18, 2026
Origin
San Leon, TX
Late night
in San Leon on Sunday
Local time
5:35 AM
CDT
Current temp
91°F
Partly Sunny
S 10 to 15 mph2% chanceLive forecast
Flood Warning
Flood Warning issued July 18 at 9:55AM CDT until July 19 at 11:00AM CDT by NWS Austin/San Antonio TX
Flood Warning
Flood Warning issued July 18 at 9:53AM CDT until July 19 at 7:15PM CDT by NWS Austin/San Antonio TX
Destination
San Antonio, TX
Late night
in San Antonio on Sunday
Local time
5:35 AM
CDT
Current temp
93°F
Partly Sunny
SSE 10 mph2% chanceLive forecast
Flood Warning
Flood Warning issued July 18 at 9:55AM CDT until July 19 at 11:00AM CDT by NWS Austin/San Antonio TX
Flood Warning
Flood Warning issued July 18 at 9:53AM CDT until July 19 at 7:15PM CDT by NWS Austin/San Antonio TX
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
4h 19m 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.
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...
9 mi from route
~22 min detour
Free
near mile 234.6
Park data from the National Park Service API. Alerts update every 2 hours.
More Details
What kind of drive is this?
This route is predominantly highway driving, with 97% of the 234.6 miles spent on major roads like the Katy Freeway and I 10. You'll experience a long stretch of 174.7 miles on the Katy Freeway before transitioning to other highways. Expect numerous exits and potential for merging traffic as you navigate through various urban and suburban areas. The transition to surface roads, if any, will be minimal and occur towards the end of your drive.
97% highway — fuel and pacing are the main things to plan.
21 navigation steps total — most of the decisions cluster near the start and finish.
Longest single stretch: 174.7 mi on Katy Freeway.
How Hard Is This Drive?
7/10
This is a straightforward highway drive that stays mostly on Katy Freeway and South Gulf Freeway. This route has several spots where lane changes, forks, or exits need your full attention. The trickiest moment comes around 11.8 miles in.
Driving Effort7/10
Demanding - plan breaks and stay ahead of the key maneuvers
Balances navigation complexity with total wheel time.
This is a demanding drive. With 10 significant decision points across 234.6 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 11.8 miles: Lane positioning matters here; at 40.3 miles: Exit ramp - move to the correct lane early. Lane positioning matters here; at 215.1 miles (I 10; US 90; TX 130): Highway fork - watch signs carefully. Lane positioning matters here.
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
Doable as a same-day drive at 4h 19m. Total distance: 234.6 miles.
Family Friendly
Moderate complexity with 1 natural rest stops along the way.
Solo Traveler
4h 19m 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 174.7 miles on Katy Freeway. 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 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. Dedicated rest areas are limited, so plan gas or food stops as your bathroom breaks.
The main spots that need attention: at 11.8 miles: Lane positioning matters here; at 40.3 miles: Exit ramp - move to the correct lane early. Lane positioning matters here; at 215.1 miles (I 10; US 90; TX 130): Highway fork - watch signs carefully. Lane positioning matters here.
Yes — San Antonio Missions National Historical Park. See the National Parks section for detour distances and tips on detours.
Possible but tiring. At 4.3 hours each way, an in-and-out day trip would put you behind the wheel for 8.6 hours — manageable with a long break at San Antonio, TX, but most travelers stay overnight.
