Upper Darby, PA to Saint Marys, PA is 285.8 miles and takes about 5h 38m via Keystone Shortway, Pennsylvania Turnpike Northeast Extension, and Mid-County Expressway, with a fuel budget near $48 and enough daylight to finish in a day. This trip stays within Pennsylvania, moving from the Northeast region towards the interior of the state. Expect a mix of highway driving and surface roads as you make your way north. With only one recommended stop and a duration under six hours, this route is very manageable for a single-day drive. It's a straightforward option if you're looking to cover ground efficiently 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
142.9 miles from Upper Darby, PA
A natural place for your longest stop of the day
, about 2h 47m into the drive
.
Main Roads
Road
Distance
Duration
Keystone Shortway
165.5 mi
3h
Pennsylvania Turnpike Northeast Extension
75 mi
1h 21m
Mid-County Expressway
10.8 mi
14m
Bennetts Valley Highway
10.5 mi
16m
Million Dollar Highway
8.3 mi
12m
State Park Road
7.5 mi
13m
South Lansdowne Avenue
3 mi
8m
West Chester Pike
2.2 mi
4m
Longest stretch:
Keystone Shortway
— 165.5 mi, about 3h
Traffic on I-80
Hour-of-day weekday pattern from 52 FHWA count stations on your route.
Peak
3 PM
~1,067 veh/hr typical
· worst 1,528
Quietest
2 AM
~190 veh/hr
Peak-to-quiet ratio
5.6×
busier at peak than in the quiet hours
12a6anoon6p11p
Averaged across 104 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 Upper Darby, PA and Saint Marys, PA.
1
Start on West Providence Road
0.3 mi·46 sec·West Providence Road
2
Turn left onto South Lansdowne Avenue
3.0 mi·8 min·South Lansdowne Avenue
Use the straight / left / right lanes.
3
Continue on Darby Road
471 ft·13 sec·Darby Road
Use the straight / left / right lanes.
4
Turn slight left onto PA 3
2.2 mi·4 min·West Chester Pike
Use the straight lane.
5
Take the exit
0.4 mi·58 sec
Toward I 476 North: Plymouth MeetingUse the straight / slight right lanes.
Exit 95Toward PA 940, I 80: Hazleton, Mount Pocono
10
Keep slight left at fork
0.2 mi·23 sec
11
Keep slight right at fork
0.3 mi·40 sec
Toward I 80 West: Hazleton
12
Merge onto I 80
166 mi·3 hr·Keystone Shortway
13
Take the exit
0.5 mi·1 min
Toward PA 153: Clearfield, Penfield
14
Keep slight right at fork
0.2 mi·32 sec
15
Turn straight onto PA 153
7.5 mi·13 min·State Park Road
16
Turn right onto PA 255
7.9 mi·12 min·Bennetts Valley Highway
17
Continue on PA 255
0.2 mi·20 sec·Million Dollar Highway
18
Continue on PA 255
2.6 mi·3 min·Bennetts Valley Highway
19
Turn straight onto PA 255
8.1 mi·12 min·Million Dollar Highway
20
Continue on PA 120; PA 255
0.1 mi·14 sec·South Saint Marys Street
21
Turn right onto PA 120; PA 255
102 ft·1 sec·Railroad Street
22
Arrive at destination
PA 120; PA 255
Trip Plan
Given the 5h 38m estimated drive time, leaving Upper Darby, PA in the morning is advisable to ensure you arrive in Saint Marys, PA with plenty of daylight. The longest stretch without a major highway change is 165.5 miles on the Keystone Shortway, so plan your fuel and rest stops accordingly before embarking on that segment. With a total fuel cost estimated at $48, it's a budget-friendly trip. Since this drive is easily completed in one day, you have flexibility in when you depart and how you pace your single recommended stop, allowing for a more relaxed experience.
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 142.9 miles from Upper Darby, PA, or about 2h 47m into the drive.
The longest continuous stretch on this route runs about 165.5 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 63 miles or 1h 19m in
Use this first pause for coffee, a restroom break, and a quick traffic check ahead.
Halfway reset
Around 142.9 miles or 2h 47m 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 27m
Traffic, exits, and arrival timing usually matter more near Saint Marys, PA than in the middle of the route.
Before You Leave
+
Open the route before leaving Upper Darby, 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 Upper Darby, PA
This is one driving day of about 285.8 miles and 5h 38m.
Your first comfortable stop window is around 63 miles from Upper Darby, 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 Keystone Shortway for about 165.5 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 12
5 decision points cluster between mile 0.3 and 258.5 — GPS handles the exact turns, but know they're coming. Your lane choice matters more than the turn itself.
5
0.3 mi into trip|~0m in|South Lansdowne Avenue
Turn left onto South Lansdowne Avenue
Lane positioning matters here
Use the straight / left / right lanes.
6
5.6 mi into trip|~13m in
Take the exit toward I 476 North: Plymouth Meeting
Exit ramp - move to the correct lane early. Lane positioning matters here
Use the straight / slight right lanes.
Toward I 476 North: Plymouth Meeting
6
91.8 mi into trip|~1h 50m in
Take the exit toward PA 940, I 80: Hazleton, Mount Pocono
Exit ramp - move to the correct lane early. Multiple destination signs - pick the right one
Exit 95
Toward PA 940, I 80: Hazleton, Mount Pocono
5
92.6 mi into trip|~1h 52m in
Keep slight right at fork toward I 80 West: Hazleton
Highway fork - watch signs carefully
Toward I 80 West: Hazleton
5
258.5 mi into trip|~4h 53m in
Take the exit toward PA 153: Clearfield, Penfield
Exit ramp - move to the correct lane early. Multiple destination signs - pick the right one
Toward PA 153: Clearfield, Penfield
Fuel & Cost
Regular Gas
$49.91 one way
$99.83 round trip
$4.44/gal25.4 MPG avg100 kg CO2
Fuel Type
$/gal
One Way
Round Trip
midgrade
$4.86
$54.65
$109.30
premium
$5.20
$58.47
$116.93
diesel
$6.28
$70.62
$141.23
Estimated Tolls: $9.75
Pennsylvania Turnpike
(75 mi)$9.75
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
$50
Tolls
$10
Meals
$25–$50
Total
$85–$110
Rough estimate based on US averages. Hotel $80–$140/night, meals $25–$50/day.
Estimated CO2 emission: 100 kg one way.
Prices: EIA weekly data, 2026-10-19.
Driving Electric?
About $30 in charging
· 1 stop
· 67% less CO2
Vehicle Type
kWh
Stops
DC Fast
Home Charge
Average EV
85.7
1
$30.01
$13.72
Efficient EV
71.5
0
$25.01
$11.43
EV Truck/SUV
114.3
1
$40.01
$18.29
Gas CO2
100 kg
EV CO2
33 kg (67% 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.
Forecast as of Oct 19, 2026
Origin
Upper Darby, PA
Night
in Upper Darby on Thursday
Local time
9:39 PM
EDT
Current temp
65°F
Sunny
N 5 to 10 mph0% chanceLive forecast
Freeze Warning
Freeze Warning issued October 18 at 10:42PM EDT until October 19 at 9:00AM EDT by NWS State College PA
Destination
Saint Marys, PA
Night
in Saint Marys on Thursday
Local time
9:39 PM
EDT
Current temp
65°F
Widespread Frost then Sunny
N 2 mph0% chanceLive forecast
Freeze Warning
Freeze Warning issued October 18 at 10:42PM EDT until October 19 at 9:00AM EDT by NWS State College PA
64°F
Harrisburg, PA
143 mi in
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
Very similar conditions
Both ends of the route are sitting at about the same temperature right now.
Road read
5h 38m 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.
Valley Forge National Historical Park
National Historical Park
Valley Forge is the place where George Washington and the Continental Army took refuge during the winter of 1777-1778. Today the park protects 3,500 acres of meadows, woodlands, historic landscapes, a...
The park represents the founding ideals of the nation, and preserves national and international symbols of freedom and democracy, including Independence Hall and the Liberty Bell. The Declaration of I...
Visit the house where wounded Polish freedom fighter Thaddeus Kosciuszko lived and hear how this brilliant military engineer designed successful fortifications during the American Revolution. See the...
Famous as the First State to ratify the Constitution, Delaware was born out of a conflict among three world powers for dominance of the Delaware Valley. From this beginning, the region developed a dis...
Park data from the National Park Service API. Alerts update every 2 hours.
More Details
What kind of drive is this?
About 30% of this 285.8-mile drive is on highways. You'll experience a long stretch of 165.5 miles on the Keystone Shortway, offering a more open cruising experience. The route transitions from the more urban-connected Mid-County Expressway and Pennsylvania Turnpike Northeast Extension to more varied surface roads as you head deeper into Pennsylvania. Be prepared for potential changes in traffic density and speed limits as you move between these road types.
30% highway, the rest on surface roads — varied driving throughout.
22 navigation steps total — most of the decisions cluster near the start and finish.
Longest single stretch: 165.5 mi on Keystone Shortway.
How Hard Is This Drive?
8/10
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 0.3 miles in near South Lansdowne Avenue.
Driving Effort8/10
Demanding - plan breaks and stay ahead of the key maneuvers
Balances navigation complexity with total wheel time.
This is a demanding drive. With 12 significant decision points across 285.8 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 0.3 miles (South Lansdowne Avenue): Lane positioning matters here; at 5.6 miles: Exit ramp - move to the correct lane early. Lane positioning matters here; at 91.8 miles: Exit ramp - move to the correct lane early. Multiple destination signs - pick the right one.
Elevation Profile
Hilly terrain with moderate elevation changes
1,687 ft56 ft
Total Climb
3,358 ft
Total Descent
1,753 ft
Highest Point
1,687 ft
~244.9 mi in
Elevation Range
1,630 ft
Notable High Points
1,634 ft at ~183.7 miles+583 ft prominence
Towns Mentioned on Route Signs
Based on OSRM destination-sign hints, not a full list of every settlement the road passes.
Between Upper Darby, PA and Saint Marys, PA, road signs point toward Mount Pocono and Penfield.
St. Marys is a city in Elk County, Pennsylvania, part of the Pennsylvania Wilds.
Sitting near the center of the Pennsylvania Wilds region, St. Marys provides a great jumping-off point for visits to the area's parks, forests, rivers, lakes, and mountains.
Doable as a same-day drive at 5h 38m. Total distance: 285.8 miles.
Family Friendly
Moderate complexity with 1 natural rest stops along the way.
Solo Traveler
5h 38m drive, comfortable solo distance.
Scenic Drive
Mixed highway & surface route profile with national parks nearby.
Frequently Asked Questions
The longest stretch is about 165.5 miles on Keystone Shortway. The full list of main roads is in the Roads section above.
Expect about $9.75 in tolls one way, starting with Pennsylvania Turnpike. 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 Saint Marys, 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 0.3 miles (South Lansdowne Avenue): Lane positioning matters here; at 5.6 miles: Exit ramp - move to the correct lane early. Lane positioning matters here; at 91.8 miles: Exit ramp - move to the correct lane early. Multiple destination signs - pick the right one.
Yes — Valley Forge National Historical Park, Independence National Historical Park and Thaddeus Kosciuszko National Memorial (4 total within detour distance). See the National Parks section for detour distances and tips on detours.
Not recommended in a single day. At 5.6 hours each way, a round trip means 11.3 hours of driving — that is an unsafe level of fatigue for most drivers. Plan at least one night at Saint Marys, PA before the return drive.
