Fog driving — Iowa Permit Test
Fog driving on the Iowa permit test — 3 rules, each with the reason behind it and a question on it while it is fresh.
The rules
In fog, use low-beam lights or fog lights, not high beams, which reflect off the fog and cause glare.
Bright high beams bounce back off the fog like a wall of light. Low beams shine lower and let you see more of the road.
Don’t use high beams — they reflect off the fog, causing glare and reduced visibility.
In fog, slow down until your speed matches your ability to see.
In thick fog you may only see a short way ahead. You need to be able to stop within that distance if something appears.
Slow down until your speed matches your ability to see.
If fog is too thick, get off the road and find a safe place to park.
When you can barely see, pushing on puts you and others at risk. Waiting in a safe spot until the fog lifts is the better choice.
If needed, get off the road and find a safe place to park.
On the test
Which lights should you use when driving in fog?
Low beams or fog lights. Bright high beams bounce back off the fog like a wall of light. Low beams shine lower and let you see more of the road. Iowa Driver's License Manual, p.60: “Don’t use high beams — they reflect off the fog, causing glare and reduced visibility.”
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 Iowa Driver's License Manual, published by the Iowa Department of Transportation, and against the state code itself. Last checked 2026-10-04.
- src/assets/drivers-manuals/IA.pdf (Iowa Driver's License Manual, edition M1170 07/23/2026, Iowa Department of Transportation, retrieved 2026-09-14; sha256 pinned in SOURCES.json)
- src/assets/drivers-manuals/IA.pages.txt (the plain pdftotext fixture every citation here was cut from and verified against; sha256 pinned in SOURCES.json)
- https://iowadot.gov/drivers-licenses-ids/driver-education/manuals-practice-tests/drivers-manual
- https://iowadot.gov/drivers-licenses-ids/driver-education/online-permit-test-skip-trip (read 2026-10-04; states no count or mark)
- https://iowadot.gov/drivers-licenses-ids/get-or-renew-drivers-licenses-ids-permits/under-18-permit-license-or-id/instruction-permit-under-age-18 (read 2026-10-04; states no count or mark)
- https://iowadot.gov/drivers-licenses-ids/driver-education/manuals-practice-tests/take-practice-test (read 2026-10-04; its 25 questions and 80% describe the practice test and are not used)
- https://www.legis.iowa.gov/docs/iac/chapter/761.604.pdf (IAC 10/1/25; 761-604.9(1): "will declare the minimum passing score for each test")
- docs/plans/iowa-exam-shape.md (every official source checked for the exam's shape, and what each gave)