Mount Lebanon, PA to South Union, PA is 237.8 miles and takes about 5h 14m via I 99 and William Penn Highway, with a fuel budget near $39 and enough daylight to finish in a day. This trip stays within the Northeast region and covers ground in Pennsylvania. It's a solid option for a single-day drive, offering a direct connection between these two points with a manageable duration. You'll experience a mixed drive profile, suggesting a blend of highway speeds and potentially more local road segments as you near your destination. Consider this route if you're looking for an efficient way to travel within the state.
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
118.9 miles from Mount Lebanon, PA
A natural place for your longest stop of the day
, about 2h 44m into the drive
.
Main Roads
Road
Distance
Duration
I 99
84.1 mi
1h 34m
William Penn Highway
61.6 mi
1h 25m
Penn-Lincoln Parkway East
14.7 mi
20m
Admiral Peary Highway
13.7 mi
19m
Keystone Shortway
12.3 mi
13m
Susquehanna Beltway
11.6 mi
13m
Appalachian Thruway
10.4 mi
11m
Frank D O'Reilly Jr Highway
5.7 mi
6m
Longest stretch:
I 99
— 84.1 mi, about 1h 34m
Turn-by-Turn Driving Directions
Step-by-step road directions between Mount Lebanon, PA and South Union, PA.
1
Start on this road
237 ft·23 sec·this road
2
Turn left
156 ft·13 sec
3
At end of road, turn right onto US 19; Yellow Belt
1.3 mi·3 min·Washington Road
Use the straight lane.
4
Turn left onto US 19; Yellow Belt
1.8 mi·3 min·Cochran Road
Use the straight / right lanes.
5
Turn right onto PA 121
2.3 mi·4 min·Greentree Road
6
Take the ramp
0.3 mi·44 sec
Toward I 376 East: Pittsburgh
7
Merge onto I 376; US 22; US 30
2.3 mi·3 min·Penn-Lincoln Parkway West
8
Keep slight right at fork onto I 376; US 22; US 30
15 mi·20 min·Penn-Lincoln Parkway East
Toward I 376 East: MonroevilleUse the straight / slight left lanes.
9
Merge onto US 22
45 mi·1 hr 5 min·William Penn Highway
Use the straight / right lanes.
10
Continue on US 22
14 mi·19 min·Admiral Peary Highway
Use the straight / right lanes.
11
Continue on US 22
17 mi·19 min·William Penn Highway
12
Continue on this road
0.5 mi·45 sec·this road
Toward I 99, US 220: Altoona, Bedford
13
Keep slight left at fork
0.9 mi·1 min
Toward I 99 North, US 220 North: Altoona
14
Merge onto I 99; US 220
41 mi·44 min·I 99; US 220
15
Keep slight left at fork onto I 99; US 220; US 322
4.0 mi·4 min·I 99; US 220; US 322
Use the straight lane.
16
Keep slight left at fork onto I 99; US 220
12 mi·14 min·I 99; US 220
Toward I 99 North, US 220 North: Bellefonte
17
Turn left
0.2 mi·31 sec
Toward I 80 East, US 220 North: WilliamsportUse the left lane.
18
Merge onto I 80; US 220
12 mi·13 min·Keystone Shortway
19
Take the exit
0.4 mi·54 sec
Toward PA 64: Pleasant Gap, Mill Hall
20
Turn left onto PA 64
4.5 mi·7 min·Nittany Valley Drive
21
Turn right onto PA 477
345 ft·6 sec·Long Run Road
22
Take the ramp
0.2 mi·39 sec
23
Turn sharp left onto US 220
5.7 mi·6 min·Frank D O'Reilly Jr Highway
24
Continue on US 220
0.3 mi·17 sec·Appalachian Thwy
25
Continue on US 220
10 mi·11 min·Appalachian Thruway
26
Continue on US 220
12 mi·13 min·Susquehanna Beltway
27
Take the exit
0.6 mi·1 min
Toward US 15 North: MansfieldUse the slight right lane.
28
Merge onto I 99; US 15
27 mi·30 min·I 99; US 15
29
Take the exit
0.3 mi·32 sec
Exit 162Toward PA 414: Morris, LibertyUse the slight right lane.
30
Turn right onto PA 414
0.6 mi·1 min·Route 414
31
Turn left onto PA 414
0.4 mi·38 sec·Blockhouse Road
32
Turn right onto PA 414
4.3 mi·7 min·Water Street
33
Turn right onto Salt Spring Road
1.5 mi·5 min·Salt Spring Road
34
Turn left onto T329
0.9 mi·3 min·Beck Road
35
Turn left onto South Union Road
81 ft·3 sec·South Union Road
36
Arrive at destination
South Union Road
Trip Plan
Given the 5h 14m duration, starting your drive in the morning from Mount Lebanon will comfortably get you to South Union before evening. With only one recommended stop, you have flexibility on where and when to break. The longest stretch is 84.1 miles on I 99, so plan a brief pause around that point if needed for fuel or a stretch. Keep an eye on your fuel gauge, especially when transitioning between major highways like I 99 and the William Penn Highway, as services can vary. This is a drive easily completed in one day, allowing for a relaxed pace.
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 118.9 miles from Mount Lebanon, PA, or about 2h 44m into the drive.
The longest continuous stretch on this route runs about 84.1 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 19m in
Use this first pause for coffee, a restroom break, and a quick traffic check ahead.
Halfway reset
Around 118.9 miles or 2h 44m 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 14m
Traffic, exits, and arrival timing usually matter more near South Union, PA than in the middle of the route.
Before You Leave
+
Open the route before leaving Mount Lebanon, PA 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 Mount Lebanon, PA
This is one driving day of about 237.8 miles and 5h 14m.
Your first comfortable stop window is around 52 miles from Mount Lebanon, PA.
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 99 for about 84.1 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 28
5 decision points cluster between mile 0.1 and 229.9 — GPS handles the exact turns, but know they're coming. Your lane choice matters more than the turn itself.
6
0.1 mi into trip|~0m in|US 19; Yellow Belt / Washington Road
At end of road, turn right onto US 19; Yellow Belt / Washington Road
Lane positioning matters here
Use the straight lane.
7
8.2 mi into trip|~15m in|I 376; US 22; US 30 / Penn-Lincoln Parkway East
Keep slight right at fork onto I 376; US 22; US 30 / Penn-Lincoln Parkway East toward I 376 East: Monroeville
Highway fork - watch signs carefully. Lane positioning matters here
Use the straight / slight left lanes.
Toward I 376 East: Monroeville
6
98.6 mi into trip|~2h 22m in
Keep slight left at fork toward I 99 North, US 220 North: Altoona
Highway fork - watch signs carefully. Multiple destination signs - pick the right one
Toward I 99 North, US 220 North: Altoona
7
156.8 mi into trip|~3h 27m in
Turn left toward I 80 East, US 220 North: Williamsport
Lane positioning matters here. Multiple destination signs - pick the right one
Use the left lane.
Toward I 80 East, US 220 North: Williamsport
8
229.9 mi into trip|~4h 54m in
Take the exit toward PA 414: Morris, Liberty
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 162
Toward PA 414: Morris, Liberty
Fuel & Cost
Regular Gas
$39.42 one way
$78.85 round trip
$4.21/gal25.4 MPG avg83 kg CO2
Fuel Type
$/gal
One Way
Round Trip
midgrade
$4.61
$43.18
$86.36
premium
$4.93
$46.12
$92.24
diesel
$5.61
$52.50
$105.01
Estimated Tolls: $0.73
Appalachian Thruway
(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
$39
Tolls
$1
Meals
$25–$50
Total
$65–$90
Rough estimate based on US averages. Hotel $80–$140/night, meals $25–$50/day.
Estimated CO2 emission: 83.2 kg one way.
Prices: EIA weekly data, 2026-04-13.
Driving Electric?
About $25 in charging
· 0 stops
· 66% less CO2
Vehicle Type
kWh
Stops
DC Fast
Home Charge
Average EV
71.3
0
$24.97
$11.41
Efficient EV
59.5
0
$20.81
$9.51
EV Truck/SUV
95.1
1
$33.29
$15.22
Gas CO2
83 kg
EV CO2
28 kg (66% 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 Apr 18, 2026
Origin
Mount Lebanon, PA
Morning
in Mount Lebanon on Sunday
Local time
10:56 AM
EDT
Current temp
57°F
Unavailable
Live forecast
Destination
South Union, PA
Morning
in South Union on Sunday
Local time
10:56 AM
EDT
Current temp
59°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
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 14m 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.
Johnstown Flood National Memorial
National Memorial
The South Fork Dam failed on Friday, May 31, 1889, and unleashed 20,000,000 tons of water that devastated Johnstown, PA. The flood killed 2,209 people but it brought the nation and the world together...
8 mi from route
~20 min detour
Free
near mile 73.8
On Tuesday morning, September 11, 2001, the U.S. came under attack when four commercial airliners were hijacked and used to strike targets on the ground. Nearly 3,000 people tragically lost their live...
27 mi from route
~68 min detour
Free
near mile 73.8
Park data from the National Park Service API. Alerts update every 2 hours.
More Details
What kind of drive is this?
This journey features a mixed drive, with 43% of the route utilizing highways. You'll encounter stretches on I 99, including the longest uninterrupted segment of 84.1 miles, which will allow for sustained driving. The Penn-Lincoln Parkway East also contributes to the faster-paced sections of your trip. As you progress, expect the character of the drive to evolve, moving from more open highway conditions to potentially more varied terrain and road types as you transition to the William Penn Highway and approach South Union. This blend offers a dynamic driving experience.
43% highway, the rest on surface roads — varied driving throughout.
36 navigation steps total — most of the decisions cluster near the start and finish.
Longest single stretch: 84.1 mi on I 99.
How Hard Is This Drive?
10/10
This route mixes highway mileage with some local-road sections near the start or finish. This route has several spots where lane changes, forks, or exits need your full attention. The trickiest moment comes around 0.1 miles in near US 19; Yellow Belt / Washington Road.
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 28 significant decision points across 237.8 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 0.1 miles (US 19; Yellow Belt / Washington Road): Lane positioning matters here; at 8.2 miles (I 376; US 22; US 30 / Penn-Lincoln Parkway East): Highway fork - watch signs carefully. Lane positioning matters here; at 98.6 miles: Highway fork - watch signs carefully. Multiple destination signs - pick the right one.
Towns Mentioned on Route Signs
Based on OSRM destination-sign hints, not a full list of every settlement the road passes.
Between Mount Lebanon, PA and South Union, PA, road signs point toward Bedford and Mill Hall.
Mt. Lebanon is an affluent suburb in Allegheny County, Pennsylvania, about seven miles south of Downtown Pittsburgh. Uptown Mt. Lebanon, a business district along Washington Road in the northern part of the township, is one of the more prominent business districts in the area outside of Pittsburgh itself.
Top landmarks
•First Church of Christ, Scientist — church building in Mt. Lebanon, United States of America
Doable as a same-day drive at 5h 14m. Total distance: 237.8 miles.
Family Friendly
Moderate complexity with 1 natural rest stops along the way.
Solo Traveler
5h 14m drive, comfortable solo distance.
Scenic Drive
Mixed highway & surface route profile with national parks nearby.
Frequently Asked Questions
The longest stretch is about 84.1 miles on I 99. The full list of main roads is in the Roads section above.
Expect about $0.73 in tolls one way, starting with Appalachian Thruway. 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.
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 South Union, PA 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 0.1 miles (US 19; Yellow Belt / Washington Road): Lane positioning matters here; at 8.2 miles (I 376; US 22; US 30 / Penn-Lincoln Parkway East): Highway fork - watch signs carefully. Lane positioning matters here; at 98.6 miles: Highway fork - watch signs carefully. Multiple destination signs - pick the right one.
Yes — Johnstown Flood National Memorial and Flight 93 National Memorial. See the National Parks section for detour distances and tips on detours.
Not recommended in a single day. At 5.2 hours each way, a round trip means 10.5 hours of driving — that is an unsafe level of fatigue for most drivers. Plan at least one night at South Union, PA before the return drive.
