Traveling from Janesville to Saint Germain covers 253.5 miles through the heart of Wisconsin. You should budget approximately 4 hours and 57 minutes of driving time, making this a manageable journey to complete in a single day. With a fuel cost of roughly $39, the trip is an efficient way to transition from southern Wisconsin into the northern reaches of the state. While you could technically make this a one-day round trip, it is most enjoyable as a dedicated one-day trek to ensure you arrive at your destination refreshed. Whether you are heading north for a weekend getaway or a longer vacation, the route provides a straightforward path across the Midwest landscape.
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
126.8 miles from City of Janesville, WI
A natural place for your longest stop of the day
, about 2h 20m into the drive
.
Main Roads
Road
Distance
Duration
I 39
165 mi
2h 57m
US 51
64.6 mi
1h 18m
County Road D
7.6 mi
12m
County Road J
4.4 mi
7m
County Highway E
3.9 mi
6m
Milton Avenue
3.1 mi
6m
County Highway D
3 mi
4m
Bradley Street
0.6 mi
<1m
Longest stretch:
I 39
— 165 mi, about 2h 57m
Turn-by-Turn Driving Directions
Step-by-step road directions between City of Janesville, WI and Saint Germain, WI.
1
Start on East Court Street
148 ft·6 sec·East Court Street
2
Turn right onto Harrison Street
513 ft·26 sec·Harrison Street
3
Turn left onto East Milwaukee Street
0.2 mi·20 sec·East Milwaukee Street
4
Turn sharp right onto Milton Avenue
3.1 mi·6 min·Milton Avenue
5
Take the exit
0.8 mi·1 min
6
Merge onto I 39; I 90
61 mi·1 hr 5 min·I 39; I 90
Use the straight / slight left lanes.
7
Keep slight right at fork onto I 39
0.2 mi·14 sec·I 39
Exit 108A; 108BToward WI 78 South, I 39 North: Merrimac, Portage, WausauUse the slight right lane.
8
Continue on I 39
104 mi·1 hr 51 min·I 39
Exit 108BToward I 39 North: Portage, Wausau
9
Merge onto US 51; WI 29
48 mi·55 min·US 51; WI 29
Use the straight / slight right lanes.
10
Keep slight left at fork onto US 51
17 mi·22 min·US 51
11
Turn right onto CTH D
7.6 mi·12 min·County Road D
12
At end of road, turn left onto WI 47; CTH D
0.6 mi·53 sec·Bradley Street
13
Turn right onto CTH D
3.0 mi·4 min·County Highway D
14
Turn straight onto CTH E
3.9 mi·6 min·County Highway E
15
Turn right onto CTH J
4.4 mi·7 min·County Road J
16
Turn left onto Parkway Road
0.1 mi·28 sec·Parkway Road
17
At end of road, turn left onto WI 70
0.1 mi·15 sec·State Highway 70
18
Arrive at destination
WI 70
Trip Plan
To maximize your travel time, plan for at least one dedicated stop to break up the nearly five-hour duration. Leaving early in the morning is your best strategy to navigate the 253.5-mile distance while the roads are clear. Since the vast majority of your time is spent on high-speed highways, keep a close eye on your fuel gauge before you exit the main corridors, as service options may change once you transition to County Road D. Because this is a single-day trip, having your snacks and music playlists ready before departure will help you maintain momentum during the long 165-mile stretch on I-39. Use your one planned stop to stretch your legs thoroughly, as the highway-heavy nature of the route can lead to fatigue if you push through the entire duration without a break.
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 126.8 miles from City of Janesville, WI, or about 2h 20m into the drive.
The longest continuous stretch on this route runs about 165 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 56 miles or 1h 4m in
Use this first pause for coffee, a restroom break, and a quick traffic check ahead.
Halfway reset
Around 126.8 miles or 2h 20m 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 51m
Traffic, exits, and arrival timing usually matter more near Saint Germain, WI than in the middle of the route.
Before You Leave
+
Open the route before leaving City of Janesville, WI 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 City of Janesville, WI
This is one driving day of about 253.5 miles and 4h 57m.
Your first comfortable stop window is around 56 miles from City of Janesville, WI.
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 39 for about 165 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 15
5 decision points cluster between mile 0 and 253.4 — GPS handles the exact turns, but know they're coming. Your lane choice matters more than the turn itself.
4
0 mi into trip|~0m in|Harrison Street
Turn right onto Harrison Street
Navigation decision point
5
4.2 mi into trip|~9m in|I 39; I 90
Merge onto I 39; I 90
Merge point - match speed before joining. Lane positioning matters here
Use the straight / slight left lanes.
9
65.5 mi into trip|~1h 15m in|I 39
Keep slight right at fork onto I 39 toward WI 78 South, I 39 North: Merrimac, Portage, Wausau
Highway fork - watch signs carefully. Lane positioning matters here. Multiple destination signs - pick the right one
Use the slight right lane.
Exit 108A; 108B
Toward WI 78 South, I 39 North: Merrimac, Porta...
5
169.3 mi into trip|~3h 6m in|US 51; WI 29
Merge onto US 51; WI 29
Merge point - match speed before joining. Lane positioning matters here
Use the straight / slight right lanes.
5
253.4 mi into trip|~4h 57m in|WI 70 / State Highway 70
At end of road, turn left onto WI 70 / State Highway 70
Navigation decision point
Fuel & Cost
Regular Gas
$39.63 one way
$79.26 round trip
$3.97/gal25.4 MPG avg89 kg CO2
Fuel Type
$/gal
One Way
Round Trip
midgrade
$4.36
$43.51
$87.03
premium
$4.89
$48.78
$97.57
diesel
$5.61
$55.97
$111.94
No toll roads detected on this route.
Estimated Trip Cost (one way, 1 person)
Fuel
$40
Meals
$25–$50
Total
$65–$90
Rough estimate based on US averages. Hotel $80–$140/night, meals $25–$50/day.
Estimated CO2 emission: 88.7 kg one way.
Prices: EIA weekly data, 2026-04-13.
Driving Electric?
About $27 in charging
· 0 stops
· 66% less CO2
Vehicle Type
kWh
Stops
DC Fast
Home Charge
Average EV
76.1
0
$26.62
$12.17
Efficient EV
63.4
0
$22.18
$10.14
EV Truck/SUV
101.4
1
$35.49
$16.22
Gas CO2
89 kg
EV CO2
30 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 15, 2026
Origin
City of Janesville, WI
Night
in City of Janesville on Saturday
Local time
11:58 PM
CDT
Current temp
48°F
Unavailable
Live forecast
Destination
Saint Germain, WI
Night
in Saint Germain on Saturday
Local time
11:58 PM
CDT
Current temp
61°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
13 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 57m 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.
Ice Age National Scenic Trail
National Scenic Trail
The Ice Age National Scenic Trail spans 1,200 miles, traverses some of Wisconsin's finest geologic and glacial features, and passes through the ancestral lands of 15 Tribes. The Trail is built, manage...
3 mi from route
~8 min detour
Free
near mile 104.9
Caution: Averill–Kelly Creek Wilderness Segment — Dangerous Ford at New Wood River
Caution: Skunk and Foster Lakes Segment — Storm Damage
Park data from the National Park Service API. Alerts update every 2 hours.
More Details
What kind of drive is this?
This drive is heavily highway-focused, with 91% of your travel occurring on major thoroughfares. You will spend the bulk of your time navigating I-39 and US-51, which provide a consistent, fast-paced rhythm for the majority of the trip. The longest uninterrupted stretch is 165 miles on I-39, allowing you to settle into a steady cruising speed. As you transition from the interstate onto US-51 and finally County Road D, the character of the road shifts from high-speed transit to a more localized experience. Expect a functional, efficient drive that prioritizes speed and directness over technical maneuvers.
91% highway — fuel and pacing are the main things to plan.
18 navigation steps total — most of the decisions cluster near the start and finish.
Longest single stretch: 165 mi on I 39.
How Hard Is This Drive?
6/10
This is a straightforward highway drive that stays mostly on I 39 and US 51. You will hit about 15 points where you need to pay attention to lane position or signs. The trickiest moment comes early in the drive near Harrison Street.
Driving Effort6/10
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 253.5 miles you will encounter 15 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: near the start (Harrison Street): Navigation decision point; at 4.2 miles (I 39; I 90): Merge point - match speed before joining. Lane positioning matters here; at 65.5 miles (I 39): Highway fork - watch signs carefully. Lane positioning matters here. 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 City of Janesville, WI and Saint Germain, WI, road signs point toward Portage and Wausau.
Portage
65.5 mi in|~1h 15m|via I 39
Wausau
65.5 mi in|~1h 15m|via I 39
Who Is This Route For?
Weekend Trip
Doable as a same-day drive at 4h 57m. Total distance: 253.5 miles.
Family Friendly
Moderate complexity with 1 natural rest stops along the way.
Solo Traveler
4h 57m drive, comfortable solo distance.
First-Time Driver
Mostly highway driving (91%). Some complex stretches to watch for.
Frequently Asked Questions
The longest stretch is about 165 miles on I 39. 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 Saint Germain, WI 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: near the start (Harrison Street): Navigation decision point; at 4.2 miles (I 39; I 90): Merge point - match speed before joining. Lane positioning matters here; at 65.5 miles (I 39): Highway fork - watch signs carefully. Lane positioning matters here. Multiple destination signs - pick the right one.
Yes — Ice Age National Scenic Trail. See the National Parks section for detour distances and tips on detours.
Possible but tiring. At 5.0 hours each way, an in-and-out day trip would put you behind the wheel for 9.9 hours — manageable with a long break at Saint Germain, WI, but most travelers stay overnight.
