California speed limits, from 65 down to 15
The posted numbers are only half the rule. California's handbook sets one principle above all of them — and then four specific limits the knowledge test expects you to know cold.
The rule above the numbers: the Basic Speed Law
You may never drive faster than is safe for current conditions, regardless of the posted limit. Traffic, road surface, weather, pedestrians and bicyclists all lower the legal speed below the number on the sign. If an exam question offers "the posted limit is always legal" as an answer, it is the wrong one.
| Limit | Where it applies |
|---|---|
| 65 mph | most California highways, unless otherwise posted |
| 55 mph | two-lane undivided highways, and any vehicle towing a trailer |
| 25 mph | business and residential districts unless posted; within 500 feet of a school while children are outside (some school zones drop to 15) |
| 15 mph | blind intersections, alleys, and within 100 feet of a railroad crossing where you cannot see 400 feet down the tracks |
The three 15 mph situations, precisely
A blind intersection is one with no stop signs at any corner — if your view is blocked, edge forward slowly until you can see. An alley is any road no wider than 25 feet used to reach the rear or side of buildings. At railroad crossings, the 15 mph limit applies within 100 feet of the tracks when you cannot see 400 feet in both directions; you may go faster only if the crossing is controlled by gates, a warning signal or a flagman.
The school bus rule, word for word
When a school bus flashes its red lights, you must stop — from either direction — until the children are safely across and the lights stop flashing. Failing to stop can cost you a fine of up to $1,000 and a one-year suspension. The single exception: the bus is on the other side of a divided or multilane highway with two or more lanes in each direction. Yellow flashing lights mean the bus is about to stop — slow down and prepare.
Test yourself on this
Speed limits fall under rules of the road — one of the heaviest topics on the knowledge test.
Questions on rules of the roadSource: California Driver's Handbook (DL 600, rev. 6/2025), Section 7 — Laws and Rules of the Road (speed limit zones, school buses) and Section 8 — Safe Driving (Basic Speed Law, highway limits). Written and checked by Fernando Aguilera. Aprobify is not affiliated with the California DMV.