Following distance — District of Columbia Permit Test
Following distance on the District of Columbia permit test — 4 rules, each with the reason behind it and a question on it while it is fresh.
The rules
Most rear-end collisions are caused by following too closely, so leave as much space as you can between you and the vehicle ahead.
If the car ahead stops suddenly, the space in front of you is the only thing that keeps you from hitting it.
Most rear-end collisions are caused by following too closely.
Watch the car ahead pass a fixed point and count 'one thousand one' to 'one thousand four'; if you reach that point before you finish counting, you are following too closely.
Counting turns a distance you cannot judge well into a time you can, and it works at any speed.
If you pass the same spot before you are finished counting to one thousand four, you are following too closely.
When following vehicles that stop often, such as buses and post office vans, allow more following distance than usual.
A bus or mail van can stop at any corner, giving you less warning than a car on a long trip.
When you are following vehicles which stop often (buses, post office vans) you should allow more following distance than usual.
In bad weather, increase the distance between you and the vehicle ahead to 4 or 5 seconds.
Rain or snow means a longer stop, so you need more time between you and the car ahead.
When driving in bad weather, you should increase the distance between your vehicle and the one ahead of you to four or five seconds.
On the test
What causes most rear-end collisions?
Following too closely. If the car ahead stops suddenly, the space in front of you is the only thing that keeps you from hitting it. DC Driver Manual, p.35: “Most rear-end collisions are caused by following too closely.”
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.
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All District of Columbia permit topics
Where these come from
Every rule here is checked against DC Driver Manual, published by the District of Columbia Department of Motor Vehicles, and against the state code itself. Last checked 2026-10-05.
- src/assets/drivers-manuals/DC.pdf (DC Driver Manual (English), Rev. 7/29/2021, District of Columbia Department of Motor Vehicles, fetched 2026-10-05 from the Wayback Machine's original-bytes capture of dmv.dc.gov; sha256 pinned in SOURCES.json)
- src/assets/drivers-manuals/DC.pages.txt (the plain pdftotext fixture every citation here was cut from and verified against; sha256 pinned in SOURCES.json)
- https://dmv.dc.gov/publication/dc-dmv-automobile-driver-manual (read 2026-10-05; links only the 2023 Issuu flipbooks)
- https://issuu.com/dcdmv/docs/dc_dmv_driver_manual_english_revised_final (the current 2023 edition, read 2026-10-05 from its public page images to diff against the pinned edition; not pinnable)
- https://dmv.dc.gov/service/knowledge-tests (read 2026-10-05; states no count or mark for the knowledge test)
- https://dcregs.dc.gov/Common/DCMR/RuleList.aspx?ChapterNum=18-1 (18 DCMR chapter 1, sections 100-114, read 2026-10-05; section 104 sets what the examination covers and states no figure)
- https://code.dccouncil.gov/us/dc/council/code/sections/50-1401.01 (D.C. Code 50-1401.01, read 2026-10-05; requires a knowledge examination and states no figure)