Channeling devices — District of Columbia Permit Test
Channeling devices on the District of Columbia permit test — 2 rules, each with the reason behind it and a question on it while it is fresh.
The rules
Barricades, cones and drums are the devices most commonly used to guide drivers through work areas.
They mark a path around the digging and the crews, so following them keeps your car out of the hole.
Barricades, cones and drums are the most commonly used devices to guide drivers safely through work areas.
At night, barricades, cones and drums may carry warning lights so drivers can see them.
A plain cone is hard to spot in the dark, and a light on it shows you the edge of the work area in time.
At night they may be equipped with warning lights for improved visibility.
On the test
Which devices are most commonly used to guide drivers safely through work areas?
Barricades, cones and drums. They mark a path around the digging and the crews, so following them keeps your car out of the hole. DC Driver Manual, p.86: “Barricades, cones and drums are the most commonly used devices to guide drivers safely through work areas.”
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
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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)