Clay, CA to San Diego, CA is 492.9 miles and takes about 9h 21m via Westside Freeway and I 5 Truck, with a fuel budget near $112 and enough daylight to finish in a day if you start early. This route covers a significant portion of California's Pacific Coast region, primarily utilizing major freeways. It's a straightforward drive that's well-suited for a single-day push for experienced drivers, or a relaxed overnight for those who prefer to break it up. You'll spend almost the entire trip on the highway, making it an efficient way to travel between Northern and Southern California.
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
246.5 miles from Clay, CA
A natural place for your longest stop of the day
, about 4h 34m into the drive
.
Main Roads
Road
Distance
Duration
Westside Freeway
250.2 mi
4h 28m
I 5 Truck
83.3 mi
1h 36m
San Diego Freeway
76.5 mi
1h 29m
Santa Ana Freeway
35 mi
40m
South Sacramento Freeway
23 mi
26m
CA 104
9.3 mi
16m
Golden State Freeway
5.3 mi
6m
Crosstown Freeway
2.4 mi
2m
Longest stretch:
Westside Freeway
— 250.2 mi, about 4h 28m
Traffic on I-5
Hour-of-day weekday pattern from 476 FHWA count stations on your route.
Peak
3 PM
~3,834 veh/hr typical
· worst 4,705
Quietest
2 AM
~535 veh/hr
Peak-to-quiet ratio
7.2×
busier at peak than in the quiet hours
12a6anoon6p11p
Averaged across 96 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 Clay, CA and San Diego, CA.
1
Start on CA 104
9.2 mi·16 min·CA 104
2
Enter roundabout onto CA 104
103 ft·2 sec·CA 104
3
Continue on CA 104
0.1 mi·11 sec·CA 104
4
Enter roundabout onto Stockton Boulevard
175 ft·3 sec·Stockton Boulevard
5
Continue on Stockton Boulevard
0.1 mi·17 sec·Stockton Boulevard
6
Take the ramp
0.1 mi·19 sec
7
Merge onto CA 99
23 mi·26 min·South Sacramento Freeway
8
Take the exit
0.5 mi·1 min
Toward CA 4
9
Merge onto CA 4
2.4 mi·2 min·Crosstown Freeway
10
Take the exit onto CA 4
0.4 mi·50 sec·CA 4
Toward I 5: Sacramento
11
Keep slight left at fork onto CA 4
0.7 mi·1 min·CA 4
Toward I 5 South
12
Merge onto I 5; CA 4
13 mi·14 min·Westside Freeway
13
Keep slight left at fork onto I 5
0.8 mi·48 sec·Westside Freeway
14
Keep slight left at fork onto I 5
237 mi·4 hr 13 min·Westside Freeway
Use the straight / slight right lanes.
15
Keep slight right at fork onto I 5 Truck
58 mi·1 hr 6 min·I 5 Truck
Use the straight / slight right lanes.
16
Keep slight left at fork onto I 5
4.1 mi·4 min·Golden State Freeway
Use the straight / slight right lanes.
17
Keep slight right at fork onto I 5 Truck
0.3 mi·17 sec·I 5 Truck
Exit 158Toward I 405 SouthUse the straight / slight right lanes.
18
Keep slight left at fork onto I 5 Truck
25 mi·29 min·I 5 Truck
Use the straight / slight right lanes.
19
Keep slight left at fork onto I 5
1.3 mi·1 min·Golden State Freeway
Toward CA 60 East, I 5 South: Pomona, Soto Street, Santa AnaUse the slight left / straight lanes.
20
Merge onto I 5
26 mi·30 min·Santa Ana Freeway
Use the straight / slight right lanes.
21
Keep slight right at fork onto I 5
0.2 mi·16 sec·Santa Ana Freeway
Use the straight / slight right lanes.
22
Take the exit
0.8 mi·57 sec
Toward Broadway, Main Street, Santa AnaUse the straight / slight right lanes.
23
Keep slight left at fork
0.1 mi·10 sec
Use the straight / slight right lanes.
24
Keep slight left at fork
0.2 mi·12 sec
Toward I 5 South
25
Merge onto I 5
0.8 mi·54 sec·Santa Ana Freeway
26
Keep slight right at fork onto I 5
0.8 mi·52 sec·Santa Ana Freeway
27
Keep slight right at fork onto I 5
1.2 mi·1 min·Santa Ana Freeway
Use the straight / slight right lanes.
28
Take the exit
0.7 mi·1 min
Exit 102Toward Newport AvenueUse the slight right lane.
29
Turn right onto Newport Avenue
0.4 mi·44 sec·Newport Avenue
Use the right lane.
30
Turn left onto Walnut Avenue
2.2 mi·4 min·Walnut Avenue
31
Turn left onto Jamboree Road
0.5 mi·37 sec·Jamboree Road
Toward CA 261 Toll North: Jamboree Road, RiversideUse the left lane.
32
Take the exit
0.3 mi·21 sec
Toward I 5 South
33
Merge onto I 5
5.5 mi·6 min·Santa Ana Freeway
Use the straight / slight right lanes.
34
Keep slight left at fork onto I 5
0.8 mi·55 sec·Santa Ana Freeway
Use the straight / slight right lanes.
35
Merge onto I 5
76 mi·1 hr 29 min·San Diego Freeway
Use the straight / slight right lanes.
36
Take the exit
0.2 mi·28 sec
Exit 17Toward Front Street, Civic Center, 2nd AvenueUse the straight / slight right lanes.
37
Keep slight right at fork
0.1 mi·14 sec
Toward Front Street, Civic Center
38
Continue on Front Street
0.5 mi·1 min·Front Street
Use the straight / left lanes.
39
Arrive at destination
Front Street
Trip Plan
Given the 9h 21m duration, starting from Clay, CA early in the morning is recommended to maximize daylight. With 2 planned stops, you can break up the 492.9 miles into manageable segments. Consider stopping around the halfway point to refuel and stretch your legs. The fuel cost is estimated at $112, so ensure your tank is full before departing and be aware of fuel prices along the I 5 corridor. Keep an eye out for the 250.2-mile stretch on Westside Freeway; this will be your longest continuous driving segment without significant breaks.
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 246.5 miles from Clay, CA, or about 4h 34m 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 108 miles or 2h 6m in
Use this first pause for coffee, a restroom break, and a quick traffic check ahead.
Halfway reset
Around 246.5 miles or 4h 34m 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 246.5 miles or 4h 34m
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 8h 10m
Traffic, exits, and arrival timing usually matter more near San Diego, CA than in the middle of the route.
Before You Leave
+
Open the route before leaving Clay, 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 Clay, CA
Aim for roughly 246 miles and 4.7 hours of wheel time on this day.
Day 2
Finish the approach into San Diego, CA
Aim for roughly 246 miles and 4.7 hours of wheel time on this day.
Your first comfortable stop window is around 108 miles from Clay, 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 34
5 decision points cluster between mile 349.1 and 492.1 — GPS handles the exact turns, but know they're coming. Your lane choice matters more than the turn itself.
8
349.1 mi into trip|~6h 29m in|I 5 Truck
Keep slight right at fork onto I 5 Truck toward I 405 South
Highway fork - watch signs carefully. Lane positioning matters here
Use the straight / slight right lanes.
Exit 158
Toward I 405 South
8
374.1 mi into trip|~6h 59m in|I 5 / Golden State Freeway
Keep slight left at fork onto I 5 / Golden State Freeway toward CA 60 East, I 5 South: Pomona, Soto Street, Santa Ana
Highway fork - watch signs carefully. Lane positioning matters here. Multiple destination signs - pick the right one
Use the slight left / straight lanes.
Toward CA 60 East, I 5 South: Pomona, Soto Stre...
7
401.4 mi into trip|~7h 31m in
Take the exit toward Broadway, Main Street, Santa Ana
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.
Toward Broadway, Main Street, Santa Ana
8
408.5 mi into trip|~7h 41m in|Jamboree Road
Turn left onto Jamboree Road toward CA 261 Toll North: Jamboree Road, Riverside
Lane positioning matters here. Multiple destination signs - pick the right one
Use the left lane.
Toward CA 261 Toll North: Jamboree Road, Rivers...
8
492.1 mi into trip|~9h 19m in
Take the exit toward Front Street, Civic Center, 2nd Avenue
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 Front Street, Civic Center, 2nd Avenue
Fuel & Cost
Regular Gas
$119.25 one way
$238.49 round trip
$6.15/gal25.4 MPG avg173 kg CO2
Fuel Type
$/gal
One Way
Round Trip
midgrade
$6.34
$123.01
$246.02
premium
$6.50
$126.06
$252.12
diesel
$6.28
$121.79
$243.58
No toll roads detected on this route.
Estimated Trip Cost (one way, 1 person)
Fuel
$119
Hotel (1n)
$80–$140
Meals
$50–$100
Total
$249–$359
Rough estimate based on US averages. Hotel $80–$140/night, meals $25–$50/day.
Estimated CO2 emission: 172.5 kg one way.
Prices: EIA weekly data, 2026-10-19.
Driving Electric?
About $52 in charging
· 1 stop
· 66% less CO2
Vehicle Type
kWh
Stops
DC Fast
Home Charge
Average EV
147.9
1
$51.75
$23.66
Efficient EV
123.2
1
$43.13
$19.72
EV Truck/SUV
197.2
2
$69.01
$31.55
Gas CO2
172 kg
EV CO2
58 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 24, 2026
Origin
Clay, CA
Morning
in Clay on Sunday
Local time
10:10 AM
PDT
Current temp
70°F
Sunny
S 5 mph0% chanceLive forecast
Coastal Flood Warning
Coastal Flood Warning issued October 23 at 11:03AM PDT until October 29 at 1:00PM PDT by NWS San Diego CA
Destination
San Diego, CA
Morning
in San Diego on Sunday
Local time
10:10 AM
PDT
Current temp
75°F
Sunny
SW 0 to 10 mph1% chanceLive forecast
Coastal Flood Warning
Coastal Flood Warning issued October 23 at 11:03AM PDT until October 29 at 1:00PM 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
5 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
9h 21m 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.
Cabrillo National Monument
National Monument
In 1542, Juan Rodriguez Cabrillo climbed out of his boat and onto shore, becoming the first European to set foot on what is now the West Coast of the United States. Cabrillo National Monument not only...
5 mi from route
~13 min detour
$20
near mile 492.9
Park Closure: Park Auditorium Closed Until Further Notice
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...
23 mi from route
~59 min detour
Free
near mile 340
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 289
Park data from the National Park Service API. Alerts update every 2 hours.
More Details
What kind of drive is this?
This trip is almost entirely highway driving, with a 99% highway share. You'll encounter the longest stretch of continuous highway at 250.2 miles on Westside Freeway. Expect frequent exits and merges as you navigate through various urban and suburban areas. The profile is mostly highway, so plan for consistent speeds and the typical traffic patterns associated with major interstates.
99% highway — fuel and pacing are the main things to plan.
39 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?
10/10
This is a straightforward highway drive that stays mostly on Westside Freeway and I 5 Truck. This route has several spots where lane changes, forks, or exits need your full attention. The trickiest moment comes around 349.1 miles in near I 5 Truck.
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 34 significant decision points across 492.9 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 349.1 miles (I 5 Truck): Highway fork - watch signs carefully. Lane positioning matters here; at 374.1 miles (I 5 / Golden State Freeway): Highway fork - watch signs carefully. Lane positioning matters here. Multiple destination signs - pick the right one; at 401.4 miles: Exit ramp - move to the correct lane early. Lane positioning matters here. Multiple destination signs - pick the right one.
Elevation Profile
Hilly terrain with moderate elevation changes
2,761 ft16 ft
Total Climb
3,252 ft
Total Descent
3,318 ft
Highest Point
2,761 ft
~316.9 mi in
Elevation Range
2,745 ft
Notable High Points
2,761 ft at ~316.9 miles+1,770 ft prominence
Towns Mentioned on Route Signs
Based on OSRM destination-sign hints, not a full list of every settlement the road passes.
Between Clay, CA and San Diego, CA, road signs point toward Santa Ana, Broadway and Riverside.
From balmy beaches with a laid-back attitude to a gleaming modern image, San Diego offers much for the tourist to enjoy. Situated on the Southern California seacoast, San Diego is the second largest city in the state, with 1.4 million residents (2020), and has long attracted travelers for its ideal climate, miles of beaches, and location on the Mexican border right across from Tijuana.
But there's much more here than surfer culture and a quick hop across the border. A rich maritime and military heritage lives on in San Diego, which is home to the Pacific Fleet of the United States Navy. The city has also become known for its part in the wildlife conservation movement, owing to the presence of the world-renowned San Diego Zoo and Safari Park and the Scripps Institution of Oceanography. Natural scenery abounds from rocky tidepools and seaside cliffs to desert hills and canyons inland.
Top landmarks
•San Diego Zoo — zoo in Balboa Park, San Diego, California, United States
•Balboa Park — historic park in San Diego, California
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 246 miles on day one.
Yes — we found about 41 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 San Diego, 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 41 rest areas along the route for bathroom stops.
The main spots that need attention: at 349.1 miles (I 5 Truck): Highway fork - watch signs carefully. Lane positioning matters here; at 374.1 miles (I 5 / Golden State Freeway): Highway fork - watch signs carefully. Lane positioning matters here. Multiple destination signs - pick the right one; at 401.4 miles: Exit ramp - move to the correct lane early. Lane positioning matters here. Multiple destination signs - pick the right one.
Yes — Cabrillo National Monument, 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 9.4 hours each way, a round trip means 18.7 hours of driving — that is an unsafe level of fatigue for most drivers. Plan at least one night at San Diego, CA before the return drive.
