Seneca Knolls to Islip is 305.7 miles and takes about 6h 17m via I 81, Keystone Shortway, and Southern State Parkway, with a fuel budget near $54 and enough daylight to finish in a day. This trip stays within New York, connecting the Northeast region of the state to its southern tip. Expect a predominantly highway experience for most of the drive, making it a straightforward option for a single-day excursion. If you're looking for an efficient way to cover ground without significant detours, this route fits the bill.
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
152.9 miles from Seneca Knolls, NY
A natural place for your longest stop of the day
, about 3h 2m into the drive
.
Main Roads
Road
Distance
Duration
I 81
128.7 mi
2h 32m
Keystone Shortway
80 mi
1h 37m
Southern State Parkway
24.7 mi
31m
I 380
23.6 mi
25m
I 690
7.4 mi
9m
Cross Bronx Expressway
6.6 mi
8m
Christopher Columbus Highway
5.5 mi
5m
Clearview Expressway
5 mi
5m
Longest stretch:
I 81
— 128.7 mi, about 2h 32m
Traffic on I-80
Hour-of-day weekday pattern from 336 FHWA count stations on your route.
Peak
3 PM
~4,190 veh/hr typical
· worst 4,979
Quietest
1 AM
~446 veh/hr
Peak-to-quiet ratio
9.4×
busier at peak than in the quiet hours
12a6anoon6p11p
Averaged across 103 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 Seneca Knolls, NY and Islip, NY.
1
Start on Jones Road
0.1 mi·22 sec·Jones Road
2
Turn sharp right onto NY 48
0.9 mi·1 min·State Fair Boulevard
3
Take the ramp
0.6 mi·1 min
Toward I 690 East
4
Merge onto I 690
7.4 mi·9 min·I 690
Use the straight / slight right lanes.
5
Take the exit
0.2 mi·30 sec
Toward I 81 South: BinghamtonUse the straight / slight right lanes.
6
Merge onto I 81
2.8 mi·4 min·I 81
Use the straight / slight right lanes.
7
Continue on I-81
0.8 mi·48 sec·I-81
8
Continue on I 81
73 mi·1 hr 25 min·I 81
Use the straight / slight right lanes.
9
Keep slight right at fork onto I 81
53 mi·1 hr 3 min·I 81
Toward I 81 South: ScrantonUse the straight lane.
10
Keep slight right at fork onto US 6
0.8 mi·1 min·US 6
Exit 187Toward I 84 East, I 380 South, US 6 East: Carbondale, Mt PoconoUse the slight left / slight right lanes.
11
Continue on I 84; I 380
3.7 mi·4 min·I 84; I 380
Toward I 84 East, I 380 South: Mount Pocono, MilfordUse the straight lane.
12
Keep slight right at fork onto I 380
24 mi·25 min·I 380
Exit 4Toward I 380 South: Mount Pocono
13
Keep slight left at fork
1.0 mi·1 min
Exit 1BToward I 80 East: Stroudsburg
14
Merge onto I 80
80 mi·1 hr 37 min·Keystone Shortway
Use the straight / right lanes.
15
Keep slight right at fork onto I 80
5.5 mi·5 min·Christopher Columbus Highway
Toward I 95: George Washington Bridge Lower LevelUse the slight right lane.
16
Keep slight left at fork
0.3 mi·23 sec
Toward I 95 North: George Washington Bridge, New York CityUse the straight / slight right lanes.
17
Keep slight right at fork
0.4 mi·38 sec
Exit 70A-BToward Leonia, TeaneckUse the slight right lane.
18
Turn right
0.2 mi·35 sec
Exit 70AToward LeoniaUse the straight / slight right lanes.
19
Turn straight onto CR 56
454 ft·9 sec·Degraw Avenue
20
Continue on CR 56
1.1 mi·2 min·Fort Lee Road
Use the straight / right lanes.
21
Continue on CR 56
469 ft·13 sec·Main Street
22
Take the ramp
472 ft·12 sec
Toward George Washington Bridge
23
Merge onto US 1; US 9; US 46
0.3 mi·28 sec·Bergen Boulevard
Use the straight / slight right lanes.
24
Take the exit
312 ft·4 sec
Toward George Washington Bridge Upper Level
25
Merge onto I 95 EXPR
0.3 mi·20 sec·I 95 EXPR
Use the straight / slight right lanes.
26
Keep slight left at fork onto I 95 EXPR
0.8 mi·1 min·I 95 EXPR
27
Continue on I 95; US 1; US 9
0.6 mi·1 min·George Washington Bridge (upper level)
Use the straight / slight right lanes.
28
Continue on I 95; US 1
0.7 mi·1 min·Trans-Manhattan Expressway
29
Continue on I 95; US 1
4.7 mi·6 min·Cross Bronx Expressway
Use the straight / slight right lanes.
30
Keep slight right at fork onto I 295
2.0 mi·2 min·Cross Bronx Expressway
Exit 6BToward I 295 South: Throgs Neck BridgeUse the straight / slight left lanes.
31
Merge onto I 295
0.6 mi·58 sec·Throgs Neck Expressway
32
Continue on I 295
2.0 mi·3 min·Throgs Neck Bridge
Use the straight / slight right lanes.
33
Continue on I 295
5.0 mi·5 min·Clearview Expressway
Use the straight / slight right lanes.
34
Continue on NY 24
0.7 mi·1 min·Hollis Court Boulevard
Use the straight lane.
35
At end of road, turn left onto NY 24
0.2 mi·35 sec·Jamaica Avenue
Use the left lane.
36
Turn right onto Hempstead Avenue
0.9 mi·2 min·Hempstead Avenue
37
Turn right onto 225th Street
228 ft·9 sec·225th Street
Use the right lane.
38
Take the ramp
0.2 mi·28 sec
Toward Cross Island Parkway South, Verrazano Bridge
39
Merge onto CI
1.3 mi·1 min·Cross Island Parkway
Use the straight / slight right lanes.
40
Take the exit
0.5 mi·1 min
Exit 25AToward Southern State Parkway East, Eastern Long IslandUse the slight left / straight lanes.
41
Merge onto SO
25 mi·31 min·Southern State Parkway
Use the straight / slight right lanes.
42
Keep slight left at fork onto SO
0.2 mi·16 sec·Southern State Parkway
Use the straight / slight right lanes.
43
Take the exit
0.2 mi·31 sec
Exit 41SToward Bay Shore Road South, Bay ShoreUse the slight right lane.
44
Turn straight onto CR 57
0.5 mi·1 min·Bay Shore Road
45
Continue on CR 57
0.3 mi·43 sec·Howells Road
46
Turn straight onto CR 57
341 ft·6 sec·Sunrise Highway
47
Keep slight right at fork onto CR 57
0.6 mi·1 min·Howells Road
Toward Howells Road SouthUse the right lane.
48
Continue on CR 57
0.2 mi·24 sec·Roosevelt Street
49
Continue on CR 57
0.7 mi·1 min·3rd Avenue
50
At end of road, turn left onto NY 27A
1.1 mi·1 min·East Main Street
51
Continue on Montauk Highway
0.2 mi·17 sec·Montauk Highway
52
Continue on NY 27A
0.8 mi·1 min·Main Street
53
Arrive at destination
NY 27A
Trip Plan
Given the 6h 17m estimated duration, leaving Seneca Knolls in the morning should allow you to reach Islip with plenty of daylight. With only one recommended stop, you have flexibility in pacing yourself. Keep an eye on your fuel, especially during the 128.7-mile stretch on I 81 where services might be less frequent. The estimated fuel cost is around $54, so budget accordingly. As you transition to the Southern State Parkway, be prepared for increased local traffic as you get closer to Long Island.
Morning Departure
Start early — leave by 6-7 AM to arrive at a reasonable hour.
Evening Departure
This is a long drive — plan for a morning departure or consider splitting it into two days.
You can normally do this drive in one day.
Plan roughly 1 meaningful break for fuel, food, and rest.
The halfway point lands around 152.9 miles from Seneca Knolls, NY, or about 3h 2m into the drive.
The longest continuous stretch on this route runs about 128.7 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 67 miles or 1h 21m in
Use this first pause for coffee, a restroom break, and a quick traffic check ahead.
Halfway reset
Around 152.9 miles or 3h 2m 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 59m
Traffic, exits, and arrival timing usually matter more near Islip, NY than in the middle of the route.
Before You Leave
+
Open the route before leaving Seneca Knolls, NY 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 Seneca Knolls, NY
This is one driving day of about 305.7 miles and 6h 17m.
Your first comfortable stop window is around 67 miles from Seneca Knolls, NY.
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 81 for about 128.7 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 33
5 decision points cluster between mile 138.7 and 301.1 — GPS handles the exact turns, but know they're coming. Your lane choice matters more than the turn itself.
9
138.7 mi into trip|~2h 46m in|US 6
Keep slight right at fork onto US 6 toward I 84 East, I 380 South, US 6 East: Carbondale, Mt Pocono
Highway fork - watch signs carefully. Lane positioning matters here. Multiple destination signs - pick the right one
Use the slight left / slight right lanes.
Exit 187
Toward I 84 East, I 380 South, US 6 East: Carbo...
8
253.2 mi into trip|~5h 2m in
Keep slight left at fork toward I 95 North: George Washington Bridge, New York City
Highway fork - watch signs carefully. Lane positioning matters here. Multiple destination signs - pick the right one
Use the straight / slight right lanes.
Toward I 95 North: George Washington Bridge, Ne...
9
253.5 mi into trip|~5h 3m in
Keep slight right at fork toward Leonia, Teaneck
Highway fork - watch signs carefully. Lane positioning matters here. Multiple destination signs - pick the right one
Use the slight right lane.
Exit 70A-B
Toward Leonia, Teaneck
8
262.9 mi into trip|~5h 17m in|I 295 / Cross Bronx Expressway
Keep slight right at fork onto I 295 / Cross Bronx Expressway toward I 295 South: Throgs Neck Bridge
Highway fork - watch signs carefully. Lane positioning matters here
Use the straight / slight left lanes.
Exit 6B
Toward I 295 South: Throgs Neck Bridge
9
301.1 mi into trip|~6h 9m in
Take the exit toward Bay Shore Road South, Bay Shore
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 41S
Toward Bay Shore Road South, Bay Shore
Fuel & Cost
Regular Gas
$53.51 one way
$107.02 round trip
$4.45/gal25.4 MPG avg107 kg CO2
Fuel Type
$/gal
One Way
Round Trip
midgrade
$4.82
$57.99
$115.97
premium
$5.23
$62.95
$125.89
diesel
$6.28
$75.53
$151.07
Estimated Tolls: $22.55
George Washington Bridge
$16.00
Throgs Neck Bridge
$6.55
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
$54
Tolls
$23
Meals
$25–$50
Total
$101–$126
Rough estimate based on US averages. Hotel $80–$140/night, meals $25–$50/day.
Estimated CO2 emission: 107 kg one way.
Prices: EIA weekly data, 2026-10-19.
Driving Electric?
About $32 in charging
· 1 stop
· 66% less CO2
Vehicle Type
kWh
Stops
DC Fast
Home Charge
Average EV
91.7
1
$32.10
$14.67
Efficient EV
76.4
0
$26.75
$12.23
EV Truck/SUV
122.3
1
$42.80
$19.56
Gas CO2
107 kg
EV CO2
36 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.
Forecast as of Oct 19, 2026
Origin
Seneca Knolls, NY
Morning
in Seneca Knolls on Friday
Local time
6:12 AM
EDT
Current temp
65°F
Sunny
SW 3 mph0% chanceLive forecast
Destination
Islip, NY
Morning
in Islip on Friday
Local time
6:12 AM
EDT
Current temp
43°F
Clear
NE 6 mph0% chanceLive 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
22 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
6h 17m on the road
Start early — leave by 6-7 AM to arrive at a reasonable hour.
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.
General Grant National Memorial
National Memorial
The final resting place of President Ulysses S. Grant and his wife, Julia, is the largest mausoleum in North America. It testifies to a people’s gratitude for the man who ended the bloodiest conflict...
5 mi from route
~12 min detour
Free
near mile 253
Caution: Lower Crypt Access Subject to Safe Conditions
Merchant’s clerk, Revolutionary War soldier, first Secretary Treasury of the United States: Alexander Hamilton’s life is memorialized at The Grange, the home he built on a country estate in uptown Man...
Before the 1960s, almost everything about living authentically as a lesbian, a bisexual person or a gay man was illegal. The Stonewall Uprising on June 28, 1969 is a milestone in the quest for civil r...
The African Burial Ground stands as the oldest and largest known excavated burial site in North America for both free and enslaved Africans. It offers a profound testament to the enduring legacy of Af...
10 mi from route
~26 min detour
Free
near mile 253
Located at the southern tip of Manhattan, Castle Clinton marks the place where New York City began and reflects the growth of both the city and the nation. Built to defend the harbor during the War of...
11 mi from route
~28 min detour
Free
near mile 253
Here at Federal Hall, George Washington took the oath of office as the first President of the United States, marking the beginning of the American constitutional republic. This historic site served as...
11 mi from route
~27 min detour
Free
near mile 253
Park data from the National Park Service API. Alerts update every 2 hours.
More Details
What kind of drive is this?
You'll spend about 67% of this 305.7-mile drive on highways. The longest continuous stretch without a major road change is 128.7 miles, primarily on I 81. After this, expect a transition to parkways, like the Southern State Parkway, which will likely feature more varied traffic patterns and exit densities as you approach your destination. The profile is mostly highway, so anticipate straightforward cruising for the majority of your travel time.
67% highway — fuel and pacing are the main things to plan.
53 navigation steps total — most of the decisions cluster near the start and finish.
Longest single stretch: 128.7 mi on I 81.
How Hard Is This Drive?
10/10
This is a straightforward highway drive that stays mostly on I 81 and Keystone Shortway. This route has several spots where lane changes, forks, or exits need your full attention. The trickiest moment comes around 138.7 miles in near US 6.
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 33 significant decision points across 305.7 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 138.7 miles (US 6): Highway fork - watch signs carefully. Lane positioning matters here. Multiple destination signs - pick the right one; at 253.2 miles: Highway fork - watch signs carefully. Lane positioning matters here. Multiple destination signs - pick the right one; at 253.5 miles: Highway fork - watch signs carefully. Lane positioning matters here. Multiple destination signs - pick the right one.
Elevation Profile
Gently rolling terrain
1,880 ft12 ft
Total Climb
2,069 ft
Total Descent
2,465 ft
Highest Point
1,880 ft
~152.9 mi in
Elevation Range
1,868 ft
Towns Mentioned on Route Signs
Based on OSRM destination-sign hints, not a full list of every settlement the road passes.
Between Seneca Knolls, NY and Islip, NY, road signs point toward Mt Pocono, Milford, New York City, Leonia, Teaneck and George Washington Bridge Upper Level - among others.
Islip (pronounced "ICE-lip") is a town on Long Island in the state of New York. Located within Suffolk County, the Town of Islip includes the villages of Brightwaters, Islandia, Ocean Beach and Saltaire. It also includes numerous hamlets including Bay Shore and Sayville which are ferry terminals for Fire Island. Other prominent communities are Bayport, Brentwood, Central Islip, Hauppauge, Islip village (the town seat), and Ronkonkoma.
Top landmarks
•Bayport Aerodrome — airport in Suffolk County, New York, United States
•Connetquot River State Park Preserve — state park in New York
•Modesty — oyster-dredging sloop built in Long Island
Doable as a same-day drive at 6h 17m. Total distance: 305.7 miles.
Family Friendly
Moderate complexity with 1 natural rest stops along the way.
Solo Traveler
6h 17m drive, plan rest stops for pacing.
Frequently Asked Questions
The longest stretch is about 128.7 miles on I 81. The full list of main roads is in the Roads section above.
Expect about $22.55 in tolls one way, starting with George Washington Bridge. 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.
Yes — we found about 25 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 Islip, NY 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 25 rest areas along the route for bathroom stops.
The main spots that need attention: at 138.7 miles (US 6): Highway fork - watch signs carefully. Lane positioning matters here. Multiple destination signs - pick the right one; at 253.2 miles: Highway fork - watch signs carefully. Lane positioning matters here. Multiple destination signs - pick the right one; at 253.5 miles: Highway fork - watch signs carefully. Lane positioning matters here. Multiple destination signs - pick the right one.
Yes — General Grant National Memorial, Hamilton Grange National Memorial and Stonewall National Monument (6 total within detour distance). See the National Parks section for detour distances and tips on detours.
Not recommended in a single day. At 6.3 hours each way, a round trip means 12.6 hours of driving — that is an unsafe level of fatigue for most drivers. Plan at least one night at Islip, NY before the return drive.
