Traffic Control Plans (MUTCD)¶

Draw a work zone, right-click it, and TrafficCAD generates a complete temporary traffic control layout per MUTCD 11th Edition (Revision 1) Part 6 — advance warning, transition tapers, buffer, work space, and termination, with channelizing devices at the cited spacing, flaggers and protection vehicles, editable dimensions, and a cited compliance report. The plan is parametric: edit the zone, the road, the speed, or any override and the whole layout re-derives.

Quick start¶

1. Make sure the road exists as a Road markup — either vectorize the area (Auto Site → draw a box; it captures OSM lanes, one-way direction, posted speed, and road class, and splits streets into per-block segments at intersections so each block's lanes are editable on their own) or draw one with the Road tool and set its lanes/width/shoulders in Selected road.
2. Draw the work zone footprint with any closed shape — Rectangle, Polygon, or Zone.
3. Right-click the shape → Generate traffic control plan.

Step 3: the drawn footprint, right-clicked — Generate traffic control plan does the rest.

TrafficCAD finds the road under the zone, works out which lanes (or shoulder) it occupies and in which direction of travel, classifies the closure strategy, and swaps your shape for a TTC plan object. One Ctrl+Z restores the original shape.

Generate directly on the satellite¶

You don't need to vectorize first — right-click a zone drawn on the bare basemap or satellite imagery and generate. TrafficCAD fetches the road network around the zone in the background (two passes: a survey pass identifies the street and its speed/class, then the plan's true station reach — advance signs can sit a mile upstream on a freeway — is derived and the fetch re-covers that whole extent along the real alignment) and commits it to a hidden sketch layer, "Road context (TTC)". The plan then renders directly on the imagery — tapers, device chains, buffers, signs, and dimensions over the real pavement — while the invisible roads keep driving its stationing, junction gaps, and sign placement.

Tick Show road context layer in the plan's panel (or toggle the layer in the Layers panel) whenever you want to see or edit the underlying alignment; hidden context roads never clip or restripe the roads you actually drew. If a Road markup already exists under the zone, it is used as before and nothing is fetched.

If no road can be found (offline, or no mapped street), the plan is created with a "no road context" error finding — draw a road manually or re-run detection later with Re-detect road.

A generated plan (TA-1-style work beyond the shoulder): advance signs at the Table 6B-1 spacings, device chains, work space, and derived dimensions — all editable.

What gets generated¶

Everything below derives from the zone geometry, the road's lane configuration, and the design speed — with every number produced by the cited MUTCD rules engine (see MUTCD Rules Data):

• Signs — real, editable sign symbols from the MUTCD catalog (see Automatic signing below): the advance series at the Table 6B-1 A/B/C spacings per approach, in-zone regulatory signs, END ROAD WORK, and cross-street warnings at intersections.
• Transition area — merging (L), shifting (½L), or shoulder (⅓L) tapers per Tables 6B-3/6B-4, drawn as device chains that follow the road around curves. Shoulders ≥ 8 ft are closed with devices in advance of a merging taper (TA-33 note 3).
• Buffer space — the longitudinal buffer at the Table 6B-2 stopping sight distance (an Option you can shorten or omit; the compliance panel tells you what the table value is).
• Work space — your drawn footprint, hatched, inside the closed-lane corridor.
• Termination area — the 50–100 ft downstream taper with ~20 ft device spacing (§6B.08 ¶12), plus an END ROAD WORK anchor when enabled.
• Channelizing devices — one dashed device line per run with a device glyph at every station: ≤ 1×speed spacing in tapers, ≤ 2×speed in tangents (§6K.01 ¶04), ~20 ft in the short tapers, and ≤ S/2 where devices substitute for the center line in two-way operation (TA-32 note 3). Pick cones, tubular markers, vertical panels, drums, or barricades; device glyphs stand up as 3D meshes when the camera tilts.
• Flaggers, vehicles, arrow boards — see Protection options.
• Dimensions — real, editable dimension markups for every component (see Dimensions).
• Labels — component callouts (BUFFER SPACE, MERGING TAPER L = …, DEVICES @ … O.C.) and a plan title with the strategy, TA citation, and design speed.

How TrafficCAD reads your work zone¶

The analyzer projects the zone onto the road's centerline and measures its station extent (along the road) and lateral extent (across it), then checks every lane and shoulder band for encroachment:

• a lane with less than 9 ft left is treated as closed (the MUTCD short-term floor, §6N.07);
• partial encroachments stay open but are width-checked;
• the affected direction(s) of travel come from the road's lane configuration (forward/reverse lanes, one-way).

From that occupancy it picks the closure strategy automatically:

Set Strategy in the panel to override the classification; the measured lane occupancy still drives the geometry.

The Selected TTC plan panel¶

Select the plan (click any of its zones/devices) to open the editor. The header reports the strategy, its TA/figure citation, the road, the work space length, and the device count.

A generated plan selected: the header cites the strategy and figure, and every value below it — speed, buffer, tapers, devices — is a control with the table value as its placeholder.

Below the controls: Basis of design (every distance and count with its MUTCD citation) and MUTCD compliance (see Compliance).

Overrides are never blocked — enter any value; if it falls below a Standard or outside Guidance, a finding tells you exactly which table or section you're deviating from.

Dimensions — selectable and editable¶

Generating a plan also creates real dimension markups — the same objects the Dimension tool draws — one for each component:

• MERGING/SHIFTING/SHOULDER TAPER — the transition length L,
• W — the lateral offset width the taper formula uses (Table 6B-4),
• BUFFER, WORK SPACE, DOWNSTREAM,
• A / B / C — the advance-sign spacings (Table 6B-1).

Because they're ordinary markups you can select, move, restyle, and relabel each one:

• Move / re-seat — drag the endpoints or the offset grip; the value re-measures live (true ground distance).
• Style — with the dimension selected, the markup style editor sets stroke color/width, text size and color, tick marks, and the upright/flat label mode.
• Label — the Selected dimension panel edits the name that prints before the value ("MERGING TAPER 540 ft"). Blank = value only.
• Delete the ones you don't want on the sheet.

Two supporting behaviors keep the numbers honest:

• Regenerate dims (panel button, or right-click the plan → Regenerate dimension markups) replaces the whole set from the current derivation — use it after changing the speed or strategy, re-shaping the zone, or when you want to discard your rearranging. One undo restores the previous set.
• Derived dims (checkbox) turns the plan's built-in, non-editable dimension overlay back on — handy as a check layer to compare your edited markups against the current MUTCD-derived values side by side.

Automatic signing¶

Generating a plan spawns the complete sign layout as real sign symbols (catalog artwork, individually movable/deletable, each carrying its MUTCD citation in its comments):

• Advance series per approach, chosen by strategy and condition: W4-2 + W20-5 + W20-1 for lane closures (LEFT/RIGHT artwork follows the taper side; "2 RIGHT LANES" wording on multi-lane closures), W9-3 for interior closures, W20-7/W20-4/W20-1 for flagger control (W3-3 for signal control), W21-5/W21-5a for shoulder work, W1-4 reverse curves for shifts and half-road crossovers, W20-3/W20-2 for closures. Distance legends adapt to the spacing ("1 MILE" at freeway setbacks), and the series trims on low-volume urban streets — always keeping W20-1 furthest upstream (§6H.02 ¶02).
• Both roadsides on divided/one-way highways (§6B.04) — every advance sign mirrors to the left side.
• In-zone regulatory signs: KEEP RIGHT (R4-7) at a center-work nose, TWO-WAY TRAFFIC (W6-3) and optional DO NOT PASS (R4-1) through half-road two-way sections, STAY IN LANE (R4-9) on shifts, YIELD (R1-2) for stop/yield one-lane control, ROAD CLOSED (R11-2) on barricade lines.
• Cross-street warnings at detected intersections: W20-1 on each side road approach at that road's own A distance (§6B.04 ¶08 — the TA-21…25 near-side/far-side/multi-lane intersection idiom).
• Optional signs included and marked — plaques (W13-1P advisory speed, distance plaques), END ROAD WORK, detour arrows carry an "OPTIONAL" note and can be excluded wholesale with the Optional signs toggle.

Set Traffic volume in the panel (the plan assumes HIGH until you do, and says so in the findings): low volume unlocks the low-volume typical applications, trims urban sign series, and validates STOP/YIELD or self-regulating one-lane control. Regenerate signs replaces the set after any change — one undo restores the old signs. The Derived signs checkbox overlays the current derivation for comparison, and unknown catalog codes keep their anchor placard instead of spawning.

Intersecting roads stay open¶

When another road crosses the one you're working on, TrafficCAD follows the manual's intersection idiom (TA-21…TA-27; TA-33 note 2): the channelizing device line stops at the near side of the cross street and resumes on the far side, and the taper/buffer/closed-corridor shading opens across the same span, so cross traffic is never corked by the mainline's devices. Devices redistribute within each piece at the cited spacing, tightening to the corners of the opening the way the figures show. The gap is sized from the side road's own drawn width plus a curb-return clearance on each side.

Around each detected intersection you also get, automatically:

• Cross-street ROAD WORK AHEAD signs on the side road's approaches at that road's own A distance (§6B.04 ¶08).
• A plan note at the junction station recording that the device line was opened and citing the treatment.
• A finding: an intersection inside the work zone raises a warning — the manual says additional devices shall be placed as needed there (TA-33 note 2 is a Standard), so confirm whether the side road should stay open, be closed, or get turn restrictions, and pick the matching typical application. An intersection in the advance/termination area is an informational note.

If the side road is actually closed for your operation, drag a work-zone edge across it or draw a second plan on the side road — the gap only models the open-to-traffic case, which is the manual's default.

Pedestrian crosswalks¶

Marked crosswalks (Crosswalk markups) crossing the plan road are detected the same way:

• A crossing inside the work space is treated as closed: R9-3a CROSSWALK CLOSED signs are placed on both roadside edges at the crossing, a basis-of-design note records it, and a warning finding reminds you to provide and sign an alternate accessible pedestrian route with detectable barriers (§6D.01, §6D.02).
• A crossing in the advance-warning or termination area stays open: the channelizing device line opens across the crossing band (the intersection idiom applied to pedestrians) while zone shading and point devices are unaffected, with an informational finding to verify pedestrians remain separated from the work.

Move the crosswalk or reshape the zone and the treatment re-derives live.

Protection options — flaggers, vehicles, arrow boards¶

Everything the typical applications show as an Option is a toggle, so you can match your agency's practice:

• Shadow vehicle (TMA) — drawn in the closed lane within the buffer; defaults on for lane-closing strategies. The manual counts only the area upstream of it as buffer (§6B.06 ¶13). Turning it off on a higher-speed closure surfaces an informational finding, not an error.
• Work vehicle — a second vehicle glyph inside the work space itself (the manual's legend distinguishes the two).
• Arrow board — placed just past the taper in the closed lane. On freeway lane closures it's a Standard (one per closed lane, TA-33 note 7 / TA-37 note 1): disabling it produces an error finding.
• Flaggers — one-lane two-way plans place a flagger at each end (coordinated, §6E.02), positioned by the taper on the closed side. Switch One-lane control to a temporary signal (TA-12), STOP/YIELD (TA-11), or self-regulating operation and the sign series updates.

Vehicles draw as detailed plan-view trucks (mirrors, bed equipment, the TMA's chevron cushion on the shadow vehicle) and flaggers as a recognizable person — hard hat, hi-vis vest, extended STOP paddle. Tilt the camera and all of them stand up as true 3D models, the flagger included.

Compliance — cited, never blocking¶

The MUTCD compliance list re-checks the plan on every edit. Severities:

• ● Error — a Standard ("shall") is violated or an override falls below a required value: taper shorter than Table 6B-3/6B-4, device spacing over the §6K.01 maximum, remaining lane under 9 ft, freeway closure without an arrow board.
• ▲ Warning — Guidance not met or a safety-critical assumption: unconfirmed design speed, buffer below Table 6B-2, tapers crossing a horizontal curve (§6B.08 ¶01), a side road inside the zone (TA-33 note 2), one-lane sections over a mile with flaggers (§6E.03).
• ℹ Info — Options and reminders: buffer omitted, shadow vehicle omitted at speed, 28-inch cone requirement on high-speed roads (§6K.03), short-duration simplifications (§6N.01), and the standing §6P.01 engineering-review note.

Every finding carries its citation, so the plan review writes itself.

Speed is safety-critical¶

The design speed drives everything — taper lengths, buffer, device spacing, sign spacing. TrafficCAD inherits the posted speed from the road (vectorized roads capture OSM maxspeed) but always flags it unconfirmed until you check Speed confirmed. Change the speed and the entire plan re-derives; press Regenerate dims to re-seat the dimension markups to the new lengths.

Editing and re-deriving¶

The plan is a live parametric object:

• Drag the work-zone vertices (select the plan; grips appear on the footprint) — tapers, buffer, devices, and zones re-derive as you drag.
• Edit the road (lanes, width, shoulders, alignment) — every plan on it follows, including the spawned dimension and sign markups: with Auto-update markups on (the default), any road, crosswalk, or junction edit that moves the derivation regenerates the tracked dims/signs to match. Your position/style edits on those markups are replaced by the regeneration — untick Auto-update markups to freeze them for manual editing (the Regenerate buttons still work on demand).
• Move the zone to another street — Re-detect road re-links the plan, inherits that road's speed/class, and re-seats the dimensions.
• Undo — generation, regeneration, re-detection, and explode are each a single Ctrl+Z step.

Callouts — move, edit, hide¶

Every derived text callout (WORK SPACE, BUFFER SPACE, taper labels, the strategy title, FLAGGER / SHADOW VEHICLE tags…) is directly editable:

• Drag a callout on the map to move it — the nudge is stored on the plan, survives re-derivation, and prints at the same spot on sheets and PDF.
• The panel's Callouts list shows every derived callout: untick to hide one, type to replace its text (empty returns the derived text), ↺ resets position, text, and visibility at once.

Dimension & callout text style¶

Dim text size / bold / color in the panel restyle the plan's derived dimension values and callouts everywhere (map, sheets, PDF). The default is a readable bold 13 px; Auto on the color returns the per-component colors. The spawned dimension markups are ordinary dimensions — style those with the standard style toolbar.

Explode to markups¶

Explode to markups (panel button, or right-click → Convert to plain markups) freezes the plan into ordinary features: zone areas, dashed device lines, one device symbol per channelizing device (true-size, 3D-capable), flagger/vehicle/arrow-board symbols, and sign-anchor placeholders. Your dimension markups stay as they are. Use it for final manual staging or agency-specific tweaks the parametric plan doesn't cover; one undo restores the parametric plan.

Sheets and PDF¶

TTC plans plot as crisp vectors on sheets and in PDF exports — zone tints, device lines and glyphs, vehicle/flagger symbols, sign-anchor codes, and every dimension with its label, at true scale. Dimension labels stay readable on rotated viewports. The plan also appears in the markup list (with its TA code and zone area) and exports with the CSV.

Tips & current limits¶

• The zone is treated as station-uniform: a diagonal zone closes what its widest point closes. Draw the footprint parallel to the road for the tightest layout.
• Work zones spanning an intersection generate the standard closure plus review flags (TA-21…TA-27 corner treatments are on the roadmap); side roads near the zone are detected and flagged.
• Very short drawn roads can't carry the full advance-warning distance — the finding "extends beyond the drawn road" tells you to extend or vectorize more road.