San Diego has a 25 mph prima facie speed limit on residential streets, the California default set by state law. School zones are typically 25 mph when children are present, while freeways such as I-5, I-8, and I-15 run up to 65 mph.
San Diego speed limits at a glance
| Road type | Limit |
|---|---|
| City streets (default) | 25 mph (40 kph) |
| Residential / school zones | 25 mph (40 kph) |
| Major roads / arterials | 35 mph (56 kph) |
| Highways through the city | 65 mph (105 kph) |
About speed limits in San Diego
San Diego follows California's prima facie speed law, which sets a 25 mph default on residential and business-district streets unless a street is signed otherwise. Because it is a prima facie limit, 25 mph is presumed reasonable but a driver can in theory be cited for less if conditions demand. Many streets outside San Diego's designated Engineering and Traffic Survey network default to this 25 mph rule, which covers most neighborhood blocks across the city. Higher-volume arterials are posted from engineering-and-traffic surveys, commonly 30 to 45 mph.
California's Assembly Bill 43, effective 2022, gave cities far more flexibility to lower speed limits based on safety and street context, undoing older rules that pushed limits upward toward the 85th-percentile speed. In February 2026, San Diego released a Comprehensive Speed Management Plan implementing AB 43 and related bills, finding that more than 20 percent of the city's roadway network, roughly 679 centerline miles, is eligible for potential speed-limit reductions. The city is moving to lower limits on many of these corridors.
Residential streets default to 25 mph, and school zones are generally 25 mph when children are present or during posted hours. California prohibits most automated speed cameras, though a state pilot program has authorized a handful of cities to test them; San Diego relies on officer enforcement rather than mailed camera tickets for speeding. Radar and LIDAR speed enforcement requires an up-to-date engineering-and-traffic survey to hold up in court.
Freeways carry the region's top limits. Interstates I-5, I-8, and I-15, along with state routes such as SR-163 and SR-52, generally run 65 mph, the California freeway maximum, with a few outlying segments posted at 70 mph. These are patrolled by the California Highway Patrol rather than city police, and officer enforcement, not cameras, applies throughout.
Enforcement
San Diego enforces speed limits with officers rather than cameras. San Diego police patrol city streets and the California Highway Patrol covers freeways, using radar and LIDAR. California generally bans automated speed cameras outside a narrow state pilot program, so San Diego does not mail speeding tickets from cameras.
Tolerance
There is no fixed automated tolerance in San Diego because it uses officer enforcement. Radar or LIDAR citations require a current engineering-and-traffic survey to be valid, and stops are made at the officer's discretion for driving above a limit deemed unsafe for conditions.
Speeding fines in San Diego
California speeding fines start from a modest base but balloon with mandatory penalty assessments that multiply the base roughly four to five times. A typical ticket for 1 to 15 mph over runs around $230 to $240 all-in, and 16 to 25 mph over around $360, before traffic-school and insurance costs. Excessive speeds above 100 mph carry base fines of $500-plus and possible license suspension.
Frequently asked questions
What is the speed limit in San Diego?
The default residential speed limit in San Diego is 25 mph, a California prima facie limit. School zones are typically 25 mph when children are present, and freeways such as I-5, I-8, and I-15 run up to 65 mph.
How does California AB 43 affect San Diego speed limits?
AB 43, effective 2022, lets cities lower limits based on safety and street context. San Diego's 2026 Speed Management Plan uses it to target more than 20 percent of the road network, about 679 centerline miles, for potential reductions.
Are there speed cameras in San Diego?
No. California generally bans automated speed cameras outside a limited state pilot program, so San Diego does not mail speeding tickets from cameras. Speed enforcement is handled by police and CHP officers using radar and LIDAR.
Are there higher limits on San Diego freeways?
Yes. City streets are largely 25 to 45 mph, but freeways including I-5, I-8, and I-15 run at the 65 mph California maximum, with a few outlying segments posted at 70 mph. These are patrolled by the California Highway Patrol.
More California speed limits
- California speed limit — statewide interstate, highway, and city limits.
- Los Angeles speed limit — city defaults, school zones, and camera enforcement.
Related tools
- Convert MPH to KPH — convert any speed reading between units.
- Car speed test — verify your speedometer accuracy.
- Live GPS speedometer — see your actual speed in the browser.
- Stopping distance calculator — how far you need to brake from each speed.
- US speed limits overview — federal background and national patterns.