Castro Valley to Fremont is 15.5 miles and takes about 23 minutes via I 880, with a fuel budget near $4 and enough daylight to finish in a day. This short trip stays within the Pacific Coast region, offering a straightforward connection between two communities in California. Given its brief distance and duration, it’s an ideal option for a quick errand, a short commute, or an easy addition to a larger regional exploration. You won't need to pack an overnight bag for this one; it's designed for a single-day journey.
Castro Valley is an unincorporated town in the inner East Bay in the Bay Area of California. It has a population of about 60,000 and is located north of Hayward and east of San Leandro and south of the Oakland hills. Since it is unincorporated, Castro Valley is governed by the County of Alameda, which has its county seat in Oakland.
Fremont is a suburban city in the southern part of the East Bay of the San Francisco Bay Area; it is the 4th largest city in the Bay Area by population. Fremont is in the southern part of Alameda County, California, between Union City to the north, Sunol and the hills to the east, Milpitas and Santa Clara County to the south, and the San Francisco Bay to the west. The city of Newark, near the edge of the Bay, is surrounded by the city of Fremont.
Fremont industry is not particularly large relative to other parts of the Bay Area, but neither is it a bedroom community. Many people in Fremont work locally in the electronics and high-tech industry, while many others commute to Silicon Valley or San Francisco locations for work.
Doable as a same-day drive at 23m. Total distance: 15.5 miles.
Family Friendly
Moderate complexity with 0 natural rest stops along the way.
Solo Traveler
23m drive, comfortable solo distance.
EV Driver
0 DC fast chargers along the route. Coverage: unknown.
First-Time Driver
Mostly highway driving (59%). Some complex stretches to watch for.
Scenic Drive
Mixed drive route profile with national parks nearby.
Drive Character
This drive is a mixed bag, with 59% of the journey taking place on the interstate. You'll spend a significant portion on I 880, experiencing its typical highway flow for up to 8 miles at a time. As you approach Fremont, the route transitions, incorporating local roads like Jackson Street and Mowry Avenue. Expect a blend of faster highway travel and more measured, signal-controlled city driving.
Expect a mix of faster highway mileage and slower local approaches near the beginning or end.
There are about 15 navigation steps in the underlying route data, so the final approach matters more than the middle miles.
I 880 is the longest continuous segment at about 8 miles.
How Hard Is This Drive?
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 0.7 miles in near CA 238 / Foothill Boulevard.
Driving Effort8/10
Focused - busy navigation packed into a short drive
Balances navigation complexity with total wheel time.
This is a short but busy drive. With 10 decision points packed into just 15.5 miles, you will need to pay attention to lane changes and exits — but the whole thing is over in 23m.
Where does it get tricky?
The main spots that need attention: at 0.7 miles (CA 238 / Foothill Boulevard): Lane positioning matters here; at 1.9 miles (A Street): Lane positioning matters here; at 2.1 miles (Mission Boulevard): Lane positioning matters here.
Critical Maneuvers
5 of 10 key points
These are the spots where you need to pay the most attention. Preview them before you drive.
6
0.7 mi into trip|~1m in|CA 238 / Foothill Boulevard
Turn left onto CA 238 / Foothill Boulevard
Lane positioning matters here
Use the left lane.
6
1.9 mi into trip|~3m in|A Street
At end of road, turn right onto A Street
Lane positioning matters here
Use the right lane.
6
2.1 mi into trip|~4m in|Mission Boulevard
Turn left onto Mission Boulevard
Lane positioning matters here
Use the left lane.
7
4.1 mi into trip|~8m in
Take the exit toward I 880 South: San Jose
Exit ramp - move to the correct lane early. Lane positioning matters here
Use the slight right lane.
Exit 26A
Toward I 880 South: San Jose
8
13.6 mi into trip|~19m in
Take the exit toward Mowry Avenue, Central Fremont
Exit ramp - move to the correct lane early. Lane positioning matters here. Multiple destination signs - pick the right one
Use the straight / slight right lanes.
Exit 17
Toward Mowry Avenue, Central Fremont
Main Roads
Road
Distance
Duration
I 880
8 mi
8m
Jackson Street
1.7 mi
3m
Mowry Avenue
1.6 mi
3m
Foothill Boulevard
1.2 mi
2m
Nimitz Freeway
1.2 mi
1m
Castro Valley Boulevard
0.7 mi
1m
Mission Boulevard
0.3 mi
<1m
A Street
0.2 mi
<1m
Longest stretch:
I 880
— 8 mi, about 8m
Turn-by-Turn Driving Directions
Step-by-step road directions between Castro Valley, CA and Fremont, CA.
1
Start on Lake Chabot Road
60 ft·4 sec·Lake Chabot Road
2
Turn left onto Castro Valley Boulevard
0.7 mi·1 min·Castro Valley Boulevard
3
Turn left onto CA 238
1.2 mi·2 min·Foothill Boulevard
Use the left lane.
4
At end of road, turn right onto A Street
0.2 mi·34 sec·A Street
Use the right lane.
5
Turn left onto Mission Boulevard
0.3 mi·44 sec·Mission Boulevard
Use the left lane.
6
Turn slight right onto CA 92
1.7 mi·3 min·Jackson Street
Use the right lane.
7
Take the exit
0.4 mi·27 sec
Exit 26AToward I 880 South: San JoseUse the slight right lane.
8
Merge onto I 880
1.2 mi·1 min·Nimitz Freeway
9
Keep slight left at fork onto I 880
2.4 mi·2 min·I 880
Use the slight left lane.
10
Keep slight left at fork onto I 880
5.6 mi·6 min·I 880
Use the slight left lane.
11
Take the exit
0.3 mi·35 sec
Exit 17Toward Mowry Avenue, Central FremontUse the straight / slight right lanes.
12
Turn left
116 ft·3 sec
Use the left lane.
13
Turn straight onto Mowry Avenue
0.1 mi·10 sec·Mowry Avenue
14
Continue on Mowry Avenue
1.5 mi·2 min·Mowry Avenue
15
Arrive at destination
Mowry Avenue
Fuel & Cost
Regular Gas
$3.56 one way
$7.13 round trip
$5.84/gal25.4 MPG avg5 kg CO2
Fuel Type
$/gal
One Way
Round Trip
midgrade
$6.02
$3.67
$7.34
premium
$6.18
$3.77
$7.54
diesel
$5.61
$3.42
$6.84
No toll roads detected on this route.
Drive Cost (one way)
Fuel
$4
Estimated CO2 emission: 5.4 kg one way.
Prices: EIA weekly data, 2026-04-13.
Driving Electric?
About $2 in charging
· 0 stops
· 60% less CO2
Vehicle Type
kWh
Stops
DC Fast
Home Charge
Average EV
4.6
0
$1.63
$0.74
Efficient EV
3.9
0
$1.36
$0.62
EV Truck/SUV
6.2
0
$2.17
$0.99
Gas CO2
5 kg
EV CO2
2 kg (60% less)
This trip is well within single-charge range for most EVs. No charging stops needed if you start fully charged.
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 17, 2026
Origin
Castro Valley, CA
Evening
in Castro Valley on Friday
Local time
7:18 PM
PDT
Current temp
73°F
Sunny
NNW 3 to 7 mph0% chanceLive forecast
Wind Advisory
Wind Advisory issued April 17 at 5:29AM PDT until April 17 at 2:00PM PDT by NWS Los Angeles/Oxnard CA
Wind Advisory
Wind Advisory issued April 17 at 5:29AM PDT until April 17 at 2:00PM PDT by NWS Los Angeles/Oxnard CA
Destination
Fremont, CA
Evening
in Fremont on Friday
Local time
7:18 PM
PDT
Current temp
67°F
Unavailable
Live forecast
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
6 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
23m on the road
The weather snapshot is not static. If you are leaving later, give both cities one more quick forecast check before departure.
Weather data from the National Weather Service. Conditions may change; check closer to your travel date.
Frequently Asked Questions
The drive from Castro Valley, CA to Fremont, CA covers 15.5 miles and takes about 23m without stops. Add 15-30 minutes for a fuel or rest stop on longer drives.
The main roads are I 880, Jackson Street, Mowry Avenue. Expect a mix of highway and local road driving.
This is a comfortable same-day trip.
The midpoint is about 7.8 miles from Castro Valley, CA. Look for rest areas, gas stations, or food options near the halfway mark.
At current regular gas prices, expect to spend about $3.56 one way. This estimate uses 25.4 MPG — your actual cost will vary with your vehicle's fuel efficiency and current gas prices.
Leave by 9 AM and you'll arrive before lunch. Even a 4 PM departure gets you there before dark in summer.
This is a short but busy drive. With 10 decision points packed into just 15.5 miles, you will need to pay attention to lane changes and exits — but the whole thing is over in 23m.
The main spots that need attention: at 0.7 miles (CA 238 / Foothill Boulevard): Lane positioning matters here; at 1.9 miles (A Street): Lane positioning matters here; at 2.1 miles (Mission Boulevard): Lane positioning matters here.
The route from Castro Valley, CA to Fremont, CA does not surface many named destination signs beyond the main corridor.
Yes. Nearby national parks include San Francisco Maritime National Historical Park, Rosie the Riveter WWII Home Front National Historical Park and Port Chicago Naval Magazine National Memorial.
How this page is built
Compiled by the Trip.ovh planning team at COD Solutions Oy from open government datasets — OSRM over OpenStreetMap for geometry, EIA for fuel prices, and NPS for national parks. See our methodology for refresh cadence and limitations.
