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Idaho Flagger Lane Closure Traffic Control Plan
On a two-lane, two-way road you close one lane and flaggers alternate both directions through the single open lane. That is MUTCD TA-10, and it is the most common work-zone setup in the country. Below are the computed dimensions for Idaho at four posted speeds — taper, advance sign spacing, buffer, and device count.
Real MUTCD dimensions, a title block, and a printable sheet — no account, no cost.
Build this plan free — takes about 2 minutesComputed MUTCD dimensions
Governing typical application: TA-10 — Lane Closure on a Two-Lane Road Using Flaggers. Assumptions: urban collector, 2 through lanes, 12 ft lanes, 12 ft lateral offset, 100 ft work space, short-term duration. Rule set MUTCD 11th Ed. + 50-state/DC adoption layer + ID/ACHD profiles, rule set 2026-08 rev 4.
| Posted speed | Taper length (one lane two way) | Advance signs A / B / C | Longitudinal buffer | Device spacing taper / tangent | Channelizing devices |
|---|---|---|---|---|---|
| 25 mph | 100 ft | 100 ft / 100 ft / 100 ft | 155 ft | 20 ft / 50 ft | 19 |
| 35 mph | 100 ft | 250 ft / 250 ft / 250 ft | 250 ft | 20 ft / 70 ft | 18 |
| 45 mph | 100 ft | 350 ft / 350 ft / 350 ft | 360 ft | 20 ft / 90 ft | 19 |
| 55 mph | 100 ft | 350 ft / 350 ft / 350 ft | 495 ft | 20 ft / 110 ft | 19 |
What applies in Idaho
- Agency rule set
- State of Idaho (MUTCD as adopted)
- MUTCD adoption
- National MUTCD adopted with a state supplement (cross-checked against a second source)
Printed on every Idaho sheet:
- Idaho has adopted the national MUTCD for use on Idaho highways and streets; the national Part 6 requirements apply unless the local highway authority has modified them.
This rule set holds no Idaho-specific permit form, review time, or closure-hour restriction, so none is shown. Those are set by whoever owns the road — state DOT, county, city, or highway district — and have to come from them.
Governing citation: Idaho Code §49-201(3) — the Idaho Transportation Board shall adopt a manual of traffic-control devices correlating with and conforming to the most recent edition of the national MUTCD; implemented by IDAPA 39.03.41 “Rules Governing Traffic Control Devices,” which adopts the MUTCD for use in Idaho. See also Idaho Code §49-209 (local traffic-control devices) for city and highway-district authority, and the ITD Traffic Manual Idaho Supplement for state-highway modifications.
Questions people actually ask
What does a flagger lane closure plan need in Idaho?
The same Part 6 elements everywhere: advance warning signs at the table spacing for the setting and speed, a flagger symbol sign and a flagger station on each approach, a 100 ft one-lane two-way taper, a longitudinal buffer equal to the stopping sight distance, and channelizing devices at the tabulated spacing. Local requirements sit on top of that, not instead of it.
How many cones do I need?
The count in the table is what the geometry requires: taper devices at the taper spacing, tangent devices along the work space at the tangent spacing, plus the downstream termination. It scales with the length of your work space, so set the real length in the builder before you buy or load.
Do two flaggers need radios?
If they cannot see each other, they need a way to communicate — radios, a pilot car, or a traffic control signal. MUTCD does not let a flagger release traffic into a lane the other end has not cleared. Sight distance between stations is the thing to check before you set up.
Real MUTCD dimensions, a title block, and a printable sheet — no account, no cost.
Build this plan free — takes about 2 minutesDISCLAIMER — READ BEFORE USE
This traffic control plan was generated by an automated tool for planning and reference purposes only. It is based on the MUTCD 11th Edition Part 6 typical applications and the agency rule set selected above. It is not a certified, sealed, or professionally engineered document and has not been reviewed against actual field conditions at this site. It must be reviewed, adapted to field conditions, and approved by a qualified person — and, where required, by the permitting agency and/or a licensed Professional Engineer — before use. Field conditions govern. The user is solely responsible for work-zone safety, for conformance with all applicable federal, state, and local requirements, and for obtaining all required permits. PM Axsus disclaims all liability arising from use of this document.