Rosemont, CA to Fontana, CA is 429.3 miles and takes about 8 hours 3 minutes via Westside Freeway and I 5 Truck, with a fuel budget near $97 and enough daylight to finish in a day. This drive stays within California, traversing the Pacific Coast region for its entirety. Given its duration and highway focus, it's a trip best suited for a single, focused driving day if you start early, or a relaxed two-day excursion. Plan for a significant portion of your travel to be on well-maintained freeways.
Trip Pace
Best split across 2 days
Treat the return leg as its own travel day rather than an afterthought.
Break Rhythm
2 planned breaks
Plan on a short reset every 3 to 4 hours to stay fresh behind the wheel.
Midpoint
214.6 miles from Rosemont, CA
A natural place for your longest stop of the day
, about 4h 1m into the drive
.
Main Roads
Road
Distance
Duration
Westside Freeway
250.2 mi
4h 28m
Foothill Freeway
67 mi
1h 17m
I 5 Truck
58.4 mi
1h 6m
South Sacramento Freeway
29.7 mi
34m
Bradshaw Road
8.9 mi
12m
Sierra Avenue
3 mi
4m
Crosstown Freeway
2.4 mi
2m
Grant Line Road
2.2 mi
3m
Longest stretch:
Westside Freeway
— 250.2 mi, about 4h 28m
Traffic on I-5
Hour-of-day weekday pattern from 89 FHWA count stations on your route.
Peak
2 PM
~1,500 veh/hr typical
· worst 2,272
Quietest
2 AM
~312 veh/hr
Peak-to-quiet ratio
4.8×
busier at peak than in the quiet hours
12a6anoon6p11p
Averaged across 44 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 Rosemont, CA and Fontana, CA.
1
Start on Rosemont Drive
0.4 mi·55 sec·Rosemont Drive
2
Turn left onto Kiefer Boulevard
0.2 mi·30 sec·Kiefer Boulevard
3
Turn right onto Thornhill Drive
0.7 mi·1 min·Thornhill Drive
4
At end of road, turn left onto CA 16
1.8 mi·2 min·Jackson Road
5
Turn right onto Bradshaw Road
6.3 mi·8 min·Bradshaw Road
Use the right lane.
6
Enter roundabout onto Bradshaw Road
81 ft·1 sec·Bradshaw Road
7
Continue on Bradshaw Road
2.6 mi·3 min·Bradshaw Road
Use the left / uturn lanes.
8
Turn right onto E2
2.2 mi·3 min·Grant Line Road
Use the right lane.
9
Continue on E2
0.1 mi·10 sec·Kammerer Road
10
Take the ramp
0.3 mi·41 sec
11
Merge onto CA 99
30 mi·34 min·South Sacramento Freeway
12
Take the exit
0.5 mi·1 min
Toward CA 4
13
Merge onto CA 4
2.4 mi·2 min·Crosstown Freeway
14
Take the exit onto CA 4
0.4 mi·50 sec·CA 4
Toward I 5: Sacramento
15
Keep slight left at fork onto CA 4
0.7 mi·1 min·CA 4
Toward I 5 South
16
Merge onto I 5; CA 4
13 mi·14 min·Westside Freeway
17
Keep slight left at fork onto I 5
0.8 mi·48 sec·Westside Freeway
18
Keep slight left at fork onto I 5
237 mi·4 hr 13 min·Westside Freeway
Use the straight / slight right lanes.
19
Keep slight right at fork onto I 5 Truck
58 mi·1 hr 6 min·I 5 Truck
Use the straight / slight right lanes.
20
Keep slight left at fork onto I 5
2.0 mi·2 min·Golden State Freeway
Use the straight / slight right lanes.
21
Take the exit
0.3 mi·17 sec
Exit 161AToward I 210 East: PasadenaUse the slight right lane.
22
Continue on I 210
24 mi·28 min·Foothill Freeway
Use the straight / slight right lanes.
23
Keep slight right at fork onto I 210
19 mi·22 min·Foothill Freeway
Toward CA 134 West, I 210 East: San Bernardino, VenturaUse the slight right lane.
24
Keep slight right at fork onto I 210
2.9 mi·3 min·Foothill Freeway
Use the straight / slight right lanes.
25
Keep slight right at fork onto CA 210
1.4 mi·1 min·Foothill Freeway
Use the straight / slight right lanes.
26
Keep slight right at fork onto CA 210
1.2 mi·1 min·Foothill Freeway
Use the straight / slight right lanes.
27
Keep slight right at fork onto CA 210
1.8 mi·2 min·Foothill Freeway
Use the straight / slight right lanes.
28
Keep slight right at fork onto CA 210
16 mi·18 min·Foothill Freeway
Use the straight / slight right lanes.
29
Take the exit
0.3 mi·46 sec
Exit 67Toward Sierra AvenueUse the straight / slight right lanes.
30
Turn right onto Sierra Avenue
3.0 mi·4 min·Sierra Avenue
Use the left / right lanes.
31
Turn left onto Merrill Avenue
205 ft·4 sec·Merrill Avenue
Use the left lane.
32
Arrive at destination
Merrill Avenue
Trip Plan
To make the most of this 8-hour drive, consider departing Rosemont before 7 AM to bypass morning traffic. With 2 planned stops, you can break up the 429.3 miles into manageable segments, perhaps stopping around the 4-hour mark. Keep an eye on your fuel gauge, especially during the longest stretch on the Westside Freeway, as services can be spread out on some highway sections. If you prefer a more leisurely pace, splitting the drive over two days with an overnight in a town along the route is also a good option.
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.
This drive is better paced as a 2-day trip.
Plan roughly 2 meaningful breaks for fuel, food, and rest.
The halfway point lands around 214.6 miles from Rosemont, CA, or about 4h 1m into the drive.
The longest continuous stretch on this route runs about 250.2 miles.
Consider an overnight stop or starting very early.
Departure
Before you leave
Start with fuel, water, and navigation already sorted so the first hour feels easy.
First stop
Around 94 miles or 1h 52m in
Use this first pause for coffee, a restroom break, and a quick traffic check ahead.
Halfway reset
Around 214.6 miles or 4h 1m in
This is the best place for your longest stop, a real meal, and a full fuel check.
Overnight split
Day 1 wrap after about 214.6 miles or 4h 1m
Stop before fatigue turns the last few hours into a grind. You want day two to start fresh, not just resumed.
Final approach
Final hour starts around 6h 52m
Traffic, exits, and arrival timing usually matter more near Fontana, CA than in the middle of the route.
Before You Leave
+
Open the route before leaving Rosemont, CA 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.
+
Pick one backup stop option before the midpoint in case traffic changes your pacing.
+
Treat this as a 2-day road trip and book the overnight stop before the busiest arrival window.
Day 1
Settle into the route from Rosemont, CA
Aim for roughly 215 miles and 4 hours of wheel time on this day.
Day 2
Finish the approach into Fontana, CA
Aim for roughly 215 miles and 4 hours of wheel time on this day.
Your first comfortable stop window is around 94 miles from Rosemont, CA.
This route usually feels better as a 2-day drive than as one long push.
Plan about 2 real breaks rather than only quick fuel stops.
The longest stretch is on Westside Freeway for about 250.2 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 61.8 and 426 — GPS handles the exact turns, but know they're coming. Your lane choice matters more than the turn itself.
6
61.8 mi into trip|~1h 17m in|I 5 / Westside Freeway
Keep slight left at fork onto I 5 / Westside Freeway
Highway fork - watch signs carefully. Lane positioning matters here
Use the straight / slight right lanes.
6
298.4 mi into trip|~5h 31m in|I 5 Truck
Keep slight right at fork onto I 5 Truck
Highway fork - watch signs carefully. Lane positioning matters here
Use the straight / slight right lanes.
7
358.7 mi into trip|~6h 40m in
Take the exit toward I 210 East: Pasadena
Exit ramp - move to the correct lane early. Lane positioning matters here
Use the slight right lane.
Exit 161A
Toward I 210 East: Pasadena
8
383.4 mi into trip|~7h 9m in|I 210 / Foothill Freeway
Keep slight right at fork onto I 210 / Foothill Freeway toward CA 134 West, I 210 East: San Bernardino, Ventura
Highway fork - watch signs carefully. Lane positioning matters here. Multiple destination signs - pick the right one
Use the slight right lane.
Toward CA 134 West, I 210 East: San Bernardino,...
7
426 mi into trip|~7h 57m in
Take the exit toward Sierra Avenue
Exit ramp - move to the correct lane early. Lane positioning matters here
Use the straight / slight right lanes.
Exit 67
Toward Sierra Avenue
Fuel & Cost
Regular Gas
$97.30 one way
$194.60 round trip
$5.76/gal25.4 MPG avg150 kg CO2
Fuel Type
$/gal
One Way
Round Trip
midgrade
$5.96
$100.67
$201.33
premium
$6.09
$102.96
$205.93
diesel
$5.40
$91.32
$182.64
No toll roads detected on this route.
Estimated Trip Cost (one way, 1 person)
Fuel
$97
Hotel (1n)
$80–$140
Meals
$50–$100
Total
$227–$337
Rough estimate based on US averages. Hotel $80–$140/night, meals $25–$50/day.
Estimated CO2 emission: 150.2 kg one way.
Prices: EIA weekly data, 2026-04-20.
Station data from NREL Alternative Fuel Stations database.
Driving Electric?
About $45 in charging
· 1 stop
· 67% less CO2
Vehicle Type
kWh
Stops
DC Fast
Home Charge
Average EV
128.8
1
$45.08
$20.61
Efficient EV
107.3
1
$37.56
$17.17
EV Truck/SUV
171.7
2
$60.10
$27.48
Gas CO2
150 kg
EV CO2
50 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 Apr 26, 2026
Origin
Rosemont, CA
Night
in Rosemont on Saturday
Local time
9:18 PM
PDT
Current temp
78°F
Unavailable
Live forecast
Destination
Fontana, CA
Night
in Fontana on Saturday
Local time
9:18 PM
PDT
Current temp
67°F
Chance Rain Showers
SW 15 to 20 mph48% chanceLive forecast
Wind Advisory
Wind Advisory issued April 25 at 1:57PM PDT until April 26 at 11:00AM PDT by NWS Las Vegas NV
Wind Advisory
Wind Advisory issued April 25 at 12:10PM PDT until April 26 at 11:00AM PDT by NWS San Diego CA
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.
For long drives, weather on day two can matter just as much as conditions at departure, so check the whole travel window rather than only the first day.
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
11 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
8h 3m on the road
This is long enough that the arrival forecast matters almost as much as departure conditions. Recheck both ends before you roll.
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.
Santa Monica Mountains National Recreation Area
National Recreation Area
The Santa Monica Mountains offer easy access to surprisingly wild places. Experience the famous beaches of Malibu or explore more than 500 miles of trails. The park abounds with historical and cultura...
22 mi from route
~54 min detour
Free
near mile 355.3
Yes, we can! Widely recognized as the most important Latino leader in the United States during the twentieth century, Cesar Chavez led farm workers and supporters in the establishment of the country's...
27 mi from route
~68 min detour
Free
near mile 296.1
Park data from the National Park Service API. Alerts update every 2 hours.
More Details
What kind of drive is this?
This drive is overwhelmingly on highways, with 96% of the 429.3 miles being freeway. You'll encounter a substantial stretch of 250.2 miles on the Westside Freeway, indicating long, uninterrupted highway cruising. The transition to surface roads will occur near the end of your trip, with the final miles likely involving more local traffic and varied speed limits. Expect to see many exit signs and potentially dense merging traffic as you approach urban areas.
96% highway — fuel and pacing are the main things to plan.
32 navigation steps total — most of the decisions cluster near the start and finish.
Longest single stretch: 250.2 mi on Westside Freeway.
How Hard Is This Drive?
9/10
This is a straightforward highway drive that stays mostly on Westside Freeway and Foothill Freeway. This route has several spots where lane changes, forks, or exits need your full attention. The trickiest moment comes around 61.8 miles in near I 5 / Westside Freeway.
Driving Effort9/10
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 429.3 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 61.8 miles (I 5 / Westside Freeway): Highway fork - watch signs carefully. Lane positioning matters here; at 298.4 miles (I 5 Truck): Highway fork - watch signs carefully. Lane positioning matters here; at 358.7 miles: Exit ramp - move to the correct lane early. Lane positioning matters here.
Towns Mentioned on Route Signs
Based on OSRM destination-sign hints, not a full list of every settlement the road passes.
On the drive from Rosemont, CA to Fontana, CA, road signs begin pointing toward Ventura along the way.
The longest stretch is about 250.2 miles on Westside Freeway. The full list of main roads is in the Roads section above.
Yes — a 2-day pace is more comfortable than one long haul. A sensible stopping point is after roughly 215 miles on day one.
Yes — we found about 35 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 Fontana, CA 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 2 meaningful breaks. There are 35 rest areas along the route for bathroom stops.
The main spots that need attention: at 61.8 miles (I 5 / Westside Freeway): Highway fork - watch signs carefully. Lane positioning matters here; at 298.4 miles (I 5 Truck): Highway fork - watch signs carefully. Lane positioning matters here; at 358.7 miles: Exit ramp - move to the correct lane early. Lane positioning matters here.
Yes — Santa Monica Mountains National Recreation Area and César E. Chávez National Monument. See the National Parks section for detour distances and tips on detours.
Not recommended in a single day. At 8.1 hours each way, a round trip means 16.1 hours of driving — that is an unsafe level of fatigue for most drivers. Plan at least one night at Fontana, CA before the return drive.
