The basic speed law — California Permit Test
The basic speed law on the California permit test — 5 rules, each with the reason behind it and a question on it while it is fresh.
The rules
In California you may never drive faster than is safe for the current road conditions, which is known as the Basic Speed Law.
The posted number is a ceiling, not a promise that the road will take it today.
In California, you may never drive faster than is safe for the current road conditions.
Regardless of the posted speed limit, your speed should depend on the number of vehicles on the road, the speed of other vehicles and the road surface.
A rough, crowded road takes more from your tires than a smooth, empty one.
The number of vehicles on the road.
Your speed should also depend on bicyclists or pedestrians on or crossing the road, on the weather, and on traffic congestion.
Every one of those is a reason the safe speed today is lower than the sign.
Bicyclists or pedestrians on or crossing the road.
Unless otherwise posted, the ideal maximum speed limit on most California highways is 65 mph.
It is the highest number California puts on an ordinary highway, and it assumes good conditions.
Unless otherwise posted, the ideal maximum speed limit on most California highways is 65 mph.
The maximum speed limit is 55 mph on a two-lane undivided highway and for vehicles towing trailers.
On an undivided road the oncoming traffic is a few feet away with nothing in between.
It is 55 mph on a two-lane undivided highway and for vehicles towing trailers.
On the test
What is California’s Basic Speed Law?
Never drive faster than is safe for conditions. The posted number is a ceiling, not a promise that the road will take it today. California Driver’s Handbook, p.67: “In California, you may never drive faster than is safe for the current road conditions.”
How this works
Most practice tests hand you a bank of questions and leave the manual somewhere else. This one puts them together.
You read one law and the reason behind it, then answer a question on that law while it is still fresh. Get it right and you move on; get it wrong and you have found the gap while it is cheap to fix, not on the morning of the exam.
Learning one rule at a time, and proving it immediately, is what turns a manual you skimmed into something you actually know — and it makes studying feel like getting somewhere rather than like waiting to find out.
What it costs
- One payment, once — not a subscription. Nothing renews and there is nothing to cancel, for an exam you sit one time.
- Free to start: a 10-question test and the first section of cards. No sign-up and no account.
- Paying opens the rest of the cards, unlimited full-length practice tests, and retests built from exactly the questions you got wrong.
- Every level up to Prepared — 3 tests passed in a row.
- Do the work, fail the real exam, and we refund you.
Where these come from
Every rule here is checked against California Driver’s Handbook, published by the California Department of Motor Vehicles, and against the state code itself. Last checked 2026-09-21.
- src/assets/drivers-manuals/CA.pdf (California Driver’s Handbook, DL 600 ENGLISH (REV. 6/2025), retrieved 2026-09-14; sha256 pinned in SOURCES.json)
- src/assets/drivers-manuals/CA.pages.txt (the pdftotext -layout fixture every citation here was cut against and verified against; sha256 pinned in SOURCES.json)
- src/assets/drivers-manuals/SOURCES.json, CA entry — the folio offset of 6 and its basis, the three non-law pages, the two sign gallery pages, and the record of why California’s exam shape is this app’s own
- docs/plans/chosen-exam-shapes.md section 5 — the decision that a state publishing neither exam figure ships 40/32 with both disclosed
- docs/plans/how-to-build-laws.md — the rule that the handbook is the syllabus and nothing enters this file without a page in it