CA Road Signs Cheat Sheet.
The night-before summary, built like the exam.

The rule that reframes the rest

Basic Speed Law: you may never drive faster than is safe for current road conditions — whatever the sign says. The posted number is a ceiling for good conditions, not permission. A citation for 65 in a 65 zone can stand in heavy rain, with no lower sign posted and no crash required.

California speed ceilings

• 65 mph on most California highways.
• 55 mph on a two-lane undivided highway, and 55 when towing a trailer — either condition alone gives the lower figure.
• 25 mph within 500 feet of a school while children are outside or crossing; some zones posted as low as 15 mph.

School buses — a broad exception

Stop from either direction when red lights flash. Stay stopped until both: children safely across and lights stopped flashing. Either alone is not enough.

Exception: no stop needed if the bus is across a divided or multilane highway (two or more lanes each direction). No physical barrier required — lane count alone releases you. This is broader than most states.

Penalty: fine up to $1,000, driving privilege suspended up to one year.

Alcohol — the strictest under-21 figure

• 0.08 adult.
• 0.04 commercial — attaches to the vehicle operated, not the licence held.
• 0.01 under 21. Not .02. A 20-year-old at 0.02 is in violation.

First zero tolerance offence: driving privilege suspended one year — not six months.

Implied consent: driving is consent to testing; refusal suspends on its own track, so beating the charge does not save the licence. Only time lowers BAC.

Permit and testing

• Learner's permit: 15½ but under 18. The half-year matters; the upper bound exists because this is the under-18 route.
• Three attempts at the knowledge test before you must reapply — and those three belong to one application.

Right-of-way

1. Four-way stop: arrival order. Right-hand rule breaks ties only.
2. Left on a green ball: yield to oncoming. Only a green arrow grants priority.
3. All-directions flashing red: treat as an all-way stop.

Signals

• Flashing red = stop sign.
• Steady yellow = red is coming; stop if safe. Too close to stop without hard braking? Continue through.

Signs and lines (national)

• Octagon stop · downward triangle yield · diamond warning · pentagon school · circle railroad. One message per shape.
• Orange work zone · blue motorist services · brown recreational and cultural.
• White = same direction; yellow = opposing. Solid yellow on your side = no passing on your side. Read outward from your own lane.
• Following distance: three seconds good conditions; more in rain, at night, or loaded.