5.7. Assemblies and Corridors

The corridor system turns an alignment plus a parametric cross-section (“assembly”) plus a ground surface into a 3D road model with cut/fill volumes, top and datum surfaces, and feature lines.

5.7.1. Overview

An assembly is a named cross-section template containing left and right rows of pre-built road elements: lanes, shoulders, curbs, sidewalks, medians, slopes. Each drawing has its own Assembly Library, accessed via Civil › Assemblies….

A corridor is a binding between one alignment, one target surface (an existing-ground TIN), and one assembly. The Build Corridor command evaluates the assembly along the alignment and produces 3D outputs in the drawing.

You need three things to build a corridor:

An alignment with horizontal geometry and a vertical profile.
A target surface (TIN) representing the existing ground.
An assembly describing the cross-section.

../../_images/assembly_concept.png — Three inputs (alignment, assembly, target TIN) combine into a single corridor entity that produces six output artifacts.

5.7.2. Assembly elements

Seven row types cover the building blocks of a typical road cross-section. Rows are added in order from the centerline outward on each side via the row-palette buttons in the Assembly Editor.

5.7.2.1. Lane

A drivable carriageway segment. Parameterised by width, cross-slope (superelevation-aware), and pavement depth. The pavement depth drives the datum surface — what sits under the road.

../../_images/element_lane.png — Lane element schematic.

Parameter	Description
Width	Lane width in metres, measured from the parent point outward.
CrossSlope	Signed cross-slope as a decimal fraction. Negative means falling away from CL. Receives the alignment’s superelevation when `Peraltable=True`.
PaveDepth	(v1 legacy — migrated to a single course on load; use Courses…) Vertical pavement thickness in metres. In the current model the pavement is a course stack — see “Pavement structure — courses and materials” below.
Peraltable	When True, the cross-slope is overridden by the alignment’s SuperelevationLeft / SuperelevationRight value at each station.

When to use it. Every road has at least one lane per direction. For divided roads, combine with a Median element between the opposing directions.

5.7.2.2. Shoulder

A narrower paved strip outboard of the outermost lane, typically sloped more steeply away from CL to shed water. Mechanically a narrower Lane with its own layer and label, named differently so quantities and feature lines distinguish it from the carriageway.

../../_images/element_shoulder.png — Shoulder element schematic (with parent Lane).

Parameter	Description
Width	Shoulder width in metres. Typical 0.5–2.5 m depending on road class.
CrossSlope	Signed cross-slope, typically steeper than the lane (e.g. −3%).
PaveDepth	(v1 legacy — migrated to a single course on load; use Courses…) Pavement thickness, usually thinner than the lane (e.g. 0.05 m).
Peraltable	When True, follows the alignment’s superelevation.

When to use it. Rural and highway designs almost always have shoulders. Urban designs typically use a Curb + Sidewalk instead.

5.7.2.3. Median

A divider strip at the centerline of a divided road, typically depressed below the running surface for drainage. Sits at the pivot.

../../_images/element_median.png — Median element schematic.

Parameter	Description
HalfWidth	Half the total median width in metres (the full median is 2 × HalfWidth across both sides).
Depth	Vertical depression below the lane level in metres.
InnerSlope	Slope of the inner face of the median (V/H).

When to use it. Divided highways and urban boulevards. Place the Median as the first row on each side so the lanes that follow sit on its outer edge.

5.7.2.4. Curb

An urban kerb — a stepped concrete profile separating the carriageway from the sidewalk. Three points define the profile: foot (at lane edge), top (raised), back (where the sidewalk begins).

../../_images/element_curb.png — Curb element schematic (with parent Lane).

Parameter	Description
FaceW	Horizontal width of the curb face in metres (typically 0.02–0.10 m).
FaceH	Vertical face height in metres (typically 0.10–0.20 m).
TopW	Top width in metres (the flat top of the kerb stone).

When to use it. Urban streets with sidewalks. Combine with a Sidewalk row immediately after the Curb.

5.7.2.5. Sidewalk

A pedestrian walking surface outboard of the curb. Mechanically similar to a Lane (width + cross-slope + depth) but typically with gentler slopes and shallower pavement.

../../_images/element_sidewalk.png — Sidewalk element schematic (with parent Lane + Curb).

Parameter	Description
Width	Sidewalk width in metres. Typical 1.0–3.0 m.
CrossSlope	Drainage slope, typically gentle (e.g. −2%).
PaveDepth	(v1 legacy — migrated to a single course on load; use Courses…) Pavement thickness, typically shallow (e.g. 0.05 m).

When to use it. Urban roads with pedestrian provision. Always follows a Curb.

5.7.2.6. Slope

The daylight chain — connects the outermost designed point to the existing-ground TIN. Walks at the cut slope until the TIN is reached if the design is above ground; walks at the fill slope if below ground.

../../_images/element_slope.png — Slope element schematic showing cut and fill daylighting.

Parameter	Description
CutSlope	Vertical-to-horizontal ratio for cut sections (design above ground). E.g. `0.6667` = 1V:1.5H, the typical default. Steeper for rock, gentler for soft soils.
FillSlope	Vertical-to-horizontal ratio for fill sections (design below ground). E.g. `0.5` = 1V:2H. Typically gentler than cut slopes.

When to use it. The last element on each side of every assembly. Without it the corridor has no defined edge to the existing-ground.

5.7.2.7. Generic

An escape hatch for cross-section elements not covered by the catalogue. Specifies a raw (DX, DY) offset from the parent point. No automatic relationship to lanes, layers, or superelevation — exactly what you type is exactly what you get.

../../_images/element_generic.png — Generic element schematic — raw DX/DY offset.

Parameter	Description
DX	Horizontal offset in metres from the parent point. Sign is absolute (not flipped by side), so author Left- and Right- side Generic rows with opposing signs if you want symmetry.
DY	Vertical offset in metres from the parent point.

When to use it. Crash barriers, retaining walls, custom guardrails, ditches that don’t fit the Slope template, or any geometry the Lane/Shoulder/Curb/Median/Sidewalk vocabulary doesn’t capture.

5.7.3. Pavement structure — courses and materials

Lane, Shoulder, and Sidewalk rows no longer carry a single pavement thickness. Each carries a course stack: an ordered list of courses, where each course is a parametric shape (material + width + thickness + edge treatment) anchored to an earlier point in the assembly.

5.7.3.1. What a course is

A course has:

Material — a name from the drawing’s material library (below).
Width / Thickness — in metres; a Width of 0 inherits the parent row’s width.
Edge treatment (left and right independently) — Vertical (a plain rectangular edge) or Taper with a slope (dh/dv), which widens the course’s bottom edge outward, producing a benched or stepped course boundary.
Anchor — a 9-point attachment: SelfPt (the course’s own corner) glued to TargetPt (a named point of an earlier structure), plus a DX/DY offset. The nine anchor points are the corners and edge midpoints of the course’s rectangle: TL / TC / TR / ML / MC / MR / BL / BC / BR (top/middle/bottom × left/centre/right).

5.7.3.2. Chain default

Leave Target blank and a course anchors to the chain default: the first course (index 0) hangs from the row’s top link (TL); course k hangs under course k − 1’s bottom-left corner (TL → BL). This is exactly the historical single-PaveDepth behaviour — templates only need explicit anchors where they deviate from a straight-down stack.

5.7.3.3. Wider / centered courses

A base or subbase course usually needs to be wider than the layer above it. To centre the extra width on both sides, set SelfPt = TC and TargetPt = BC (top-centre onto bottom-centre) together with a Width greater than the row width: the course centres itself under the course above and steps out evenly on both sides. The shipped Base course instead widens outward only (see below): it keeps the default anchor, so its inner edge stays pinned directly under the course above (and ultimately under the row’s own inner anchor) while the full extra width goes on the outer edge (width = W + 0.6).

5.7.3.4. Taper feet

Set an edge to Taper with a slope to get a widening foot instead of a vertical step — typical for a subbase course that needs to bear on undisturbed ground beyond the layers above it. The shipped Subbase course uses Taper 1:1 on its outer edge only — the inner edge stays vertical, pinned at the row’s own inner anchor — with width = W + 1.2.

5.7.3.5. Cross-row anchoring

A course’s Target field can name another row’s structure, not just “the course above” — e.g. a drainage course anchored to LaneL.Subbase.BR ties its self point to the bottom-right corner of the left lane’s subbase course, letting one row’s stack key off another row’s. Anchoring to a structure that hasn’t been built yet (a forward reference, or a cycle) fails the build with a console error naming the unresolved target instead of crashing — fix the name and rebuild.

5.7.3.6. Drawing-level material library

Every drawing has its own material library (independent of the assembly library), opened with the Materials… button in the Assembly Editor header. It comes seeded with seven defaults:

Asphalt Wearing
Asphalt Binder
Asphalt Base
Base (crushed stone)
Subbase
Concrete
Drainage gravel

Each material is a name plus a display colour; add, delete, or recolour entries freely, and reference any of them from any course’s Material field.

5.7.3.7. The datum: bottom of the last course

The corridor’s datum surface follows the outer bottom corners of a row’s LAST course — not whichever course happens to be geometrically deepest. Because custom anchors (cross-row targets, DX/DY offsets) mean the true deepest bottom isn’t knowable until the whole stack resolves, the rule is simply “the deepest course goes last”; every shipped template already follows it (subbase is always the final course). Curb, Median, and Generic rows still advance the datum chain the way they always did (to their Back / Edge / offset point). A row with no courses (a “zero-course” row — see below) advances the datum from its own top link only.

5.7.3.8. Quantities: per-material volumes + excavation-to-formation

BUILDCORRIDOR now prints, after the usual cut/fill/net line:

Excavation (to formation) — the volume between existing ground and the datum surface where ground sits above datum, i.e. what actually has to be dug to reach subgrade. This is distinct from the ground-vs-top cut/fill figure, which ignores everything below the finished road surface.
A material table, one row per material referenced anywhere in the assembly, each the integrated volume of every course tagged with that material along the whole corridor.

5.7.3.9. Known v1 simplifications

Two shortcuts are accepted in this phase and may be refined later. (The 2026-07-22 final review corrected both this section and the shipped templates themselves — see below; the previously-published “roughly 0.075 m²” figure was wrong on top of describing the wrong joint, by about 8x.)

CL/median joint — none. Base and Subbase widen outward only from each row’s own inner anchor (never back past CL or a median edge), so on a single-lane side (Rural, Rural-Narrow, Urban) the two lanes’ courses meet exactly at the shared edge with zero overlap.
Adjacent-lane stack overlap (multi-lane sides only). On a multi-lane side (Urban-Boulevard, Highway, Freeway) each lane’s Base/Subbase still widens outward past its own outer edge into the footprint of the next lane, whose own courses start fresh from its own inner edge and never reach back — so the same kind of double count still happens, just at the internal lane-to-lane joint instead of at CL. For the shipped stacks: Base overlaps 0.6 m × 0.25 m = 0.15 m², Subbase overlaps 1.5 m (1.2 m rectangle + 0.3 m taper foot) × 0.30 m = 0.45 m², roughly 0.6 m² of cross-section per internal lane-to-lane joint (every shipped multi-lane template’s lane width exceeds the 1.5 m Subbase reach, so this figure is exact, not capped by a narrower neighbour).
Shoulder interface. The same outward reach also overlaps a Lane’s own following Shoulder — capped by the shoulder’s width where that is narrower than the 0.6 m/1.5 m reach (e.g. Rural-2x3.5’s 1.0 m-wide shoulder caps the Subbase overlap at 1.0 m × 0.30 m = 0.30 m² rather than the full 0.45 m²) — on top of the pre-existing small thickness step where the shoulder’s own Wearing course meets the lane’s Binder course rather than tying in continuously. A fully continuous tie-in is possible today via cross-row anchors but the shipped templates don’t yet author it — planned template work for a later phase.

5.7.3.10. Zero-course rows

A pavement row (lane/shoulder/sidewalk) with an empty course array is a legal “zero-course” row: for datum purposes it behaves like a bare top-only row — only its top link is emitted, no separate datum point is paired to it, and the next row’s stack continues from that top link exactly as before courses existed. This is also the shape a lane/shoulder/sidewalk row takes if you delete every row in its Courses… dialog.

5.7.4. Section styles

Corridor cross-sections — both model-space section views (TAECC_SECTIONVIEW) and the section sheets generated for plotting (TAECC_SECTIONSHEET) — draw their appearance from a named corridor section style. A style is a single named record that controls material fills (solid colour or hatch), per-element outline colours, the corridor silhouette pen, the background/grid, cut/fill shading, and four independent annotation toggles. Styles live in a library on the drawing, exactly like the alignment, surface, and profile-view style libraries; a view or sheet picks one by name, and a blank name — or a name that no longer exists in the library — falls back to Standard.

Geometry (extents, datum/top elevation, vertical exaggeration, title) stays on the view/sheet itself; the style only ever controls how that geometry is drawn.

5.7.4.1. Built-in styles

Every drawing’s corridor section style library ships with two built-in styles that cannot be renamed or deleted:

Style	Description
Standard	Solid material fills using each material’s colour from the drawing’s material library (the same colours seen in the Assembly Editor preview), grey course outlines, and a yellow dash-dot corridor silhouette.
Monochrome	Plot-ready: white background, black pens throughout (grid, ground, outlines, silhouette), cut/fill shading turned off, and all seven default materials filled with a black ANSI31 hatch (alternating 0°/90° angle material-to-material) instead of a solid colour.

Both built-ins, and any custom style you add, are available to every section view and sheet in the drawing.

5.7.4.2. Opening the Style Editor

Civil › Style Manager, then select Section View Styles in the left-hand category tree. The editor embeds in the manager’s right pane: a left list strip of every style in the library — New, Duplicate, Rename, Delete buttons below it (Standard is protected from rename and delete) — and a tabbed panel on the right with five tabs: View, Ground, Corridor, Annotations, Preview.

5.7.4.3. Editable fields

View tab
Field	Meaning
Show grid	Toggles the background grid.
Background / grid / minor-grid colour	Colours for the view background and the major/minor grid lines.
Major/minor grid X/Y	Grid line spacing, horizontal and vertical, in drawing units.
Axis text height	Pixel height of the offset/elevation axis labels.

Ground tab
Field	Meaning
Ground pen colour / width	Pen for the existing-ground surface polyline(s).
Show cut/fill shading	Toggles the tinted region between existing ground and the corridor’s top surface.
Cut colour / Fill colour	Shading colours for the cut region (ground above design) and the fill region (ground below design).

Corridor tab
Field	Meaning
Show material fills	Master toggle for every course-shape fill (solid or hatch).
Overrides grid	Per-material fill overrides — see “Material fills and overrides” below.
Outline colours (7)	One colour per row kind — Lane, Shoulder, Median, Curb, Sidewalk, Slope, Generic — for the course-shape outlines of that kind.
Silhouette colour / width / style	Pen for the corridor’s outer silhouette (Top left-to-right, Datum right-to-left) — the single yellow dash-dot line sections drew before this feature shipped.
Course-line colour	Reserved colour field for course-boundary lines; the shipped renderer currently draws course boundaries through the outline pens above.

Annotations tab
Field	Meaning
Show slope/width labels	`W=<width> s=<slope>%` labels on each segment of the corridor’s top surface.
Show point marks / Show point names	Marker + name for every named corridor point (`CL`, `EPS`, …) carried on the section.
Show area block	Per-station cut/fill/excavation-to-formation figures plus a per-material area table, drawn beside the section.
Show legend / Legend per sheet	Material-color legend box; per sheet draws one legend for the whole sheet instead of one per section cell.
Annotation text height	Pixel height shared by every annotation label.

The Preview tab paints a small synthetic section (two course shapes plus a ground polyline) through the same renderer used for real section views and sheets, so every field change is visible immediately without building a corridor.

5.7.4.4. Material fills and overrides

Every course shape resolves its fill in this order:

Override — if the style has a row for the shape’s material in the Corridor tab’s overrides grid, that row wins: Mode (typed as solid or hatch), and for hatch a Pattern name (e.g. ANSI31, any pattern from the drawing’s hatch-pattern library), Scale, Angle, and Colour.
Material colour — otherwise, the shape fills solid with its material’s colour from the drawing’s material library (the same library the Assembly Editor’s Materials… button opens).
Row-kind fallback — untagged shapes (curbs, medians — see “Pavement structure” above) fall back to a colour keyed by row kind.

This is the same resolution the Assembly Editor’s schematic preview uses (see “Editor display” below), so a material recoloured via Materials… updates consistently everywhere: assembly preview, thumbnails, section views, and section sheets.

Add or remove override rows with the grid’s Add/Delete buttons; each row is independent, so a style can hatch-fill some materials while leaving others solid.

5.7.4.5. Persistence

The style library is saved into the drawing (IQML/IQZ) under a CorridorSectionStyles element, alongside the other civil style libraries. Section views and sheets store only the style name; resolution to a concrete style happens at draw time, so a missing or deleted style name falls back to Standard without invalidating the view or sheet. Because assemblies and corridor sections were not previously released, there is no legacy-drawing migration concern — every existing view/sheet simply resolves as Standard.

Note

The Create Section Sheet… dialog’s Settings tab now includes a Section style combo (defaulting to Standard) so a new sheet can be assigned any style, including Monochrome, at creation time. There is still no per-entity control to switch an existing view or sheet to a different style after the fact — use the Preview tab above to check how any style will render before that control ships in a later phase.

5.7.5. Conditional rows, ditches and benching

(Corridor v1.3 Phase 5.) Three additions let an assembly’s daylight side adapt to the ground it actually meets, instead of always resolving the same geometry: a per-row Cut/Fill condition, a trapezoidal Ditch row for the cut side, and benching — tall daylights broken into repeated lift-and-bench steps rather than one long slope face. A related geometry fix ships alongside them: the daylight hinge now springs from the true edge of excavation on both branches (see “The excavation-edge hinge fix” below).

5.7.5.1. Row condition: Always / Cut / Fill

Every row in the Assembly Editor grid now carries a Cond column (inserted right after Name), a three-way choice: blank/Always (the row is unconditional — today’s behaviour, and the default for every existing row), Cut, or Fill. A row set to Cut or Fill only contributes its geometry, area, and section-view shapes at stations where the corridor resolver decides that side of the alignment is actually in cut (respectively fill) — at every other station the row emits nothing at all, as if it had never been authored.

The decision is made once per side per station, at the daylight hinge (the point described in the hinge fix below): the resolver probes the target surface directly above/below the hinge — ground higher than the hinge means the station is in cut on that side, otherwise it’s in fill — then activates every Cut-conditioned row and deactivates every Fill-conditioned row, or vice-versa. The losing branch is not merely hidden: it contributes zero to cut/fill/ excavation quantities, and its shapes never reach the section views or section sheets, exactly as if it were pruned from the assembly for that station.

In the Assembly Editor’s live preview, conditional geometry is drawn schematically on both branches at once so you can review each side’s design without building a corridor: the cut branch dashed and tinted orange, the fill branch dashed and tinted green. Only one branch will actually resolve at any given corridor station, but the preview always shows both so a conditional ditch or bench setup can be checked without needing test ground.

../../_images/element_ditch.png — A cut-only Ditch row (orange, dashed) ahead of the daylight.

5.7.5.2. Ditch

Ditch is a new row kind for a trapezoidal drainage channel, added with the +Ditch button under each side’s row grid (next to the other row-palette buttons). A new ditch row defaults to name Ditch, layer C-DTCH, and condition Cut — it is meant for the cut branch and is authored that way by default, though any condition is legal if you have an unusual use for it.

Parameter	Description
Depth	Vertical depth of the ditch invert below the point it springs from, in metres.
BottomWidth	Width of the ditch’s flat invert in metres. 0 produces a V-ditch (no flat bottom, the two slopes meet at a point).
ForeSlope	Slope of the near (inboard) face, as 1:n (rise:run — e.g. `2.0` = 1:2).
BackSlope	Slope of the far (outboard) face, as 1:n. Edited in the row params dialog (double-click any P column of a Ditch row) rather than the grid, alongside Depth/BottomWidth/ForeSlope.

A ditch springs from the excavation edge exactly like an unconditional daylight would, then walks down at ForeSlope to the invert, across BottomWidth, and back up at BackSlope — and it is that rising backslope which becomes the starting slope of the cut daylight chain that follows it, so the ditch and the cut face read as one continuous excavated profile rather than two unrelated elements. The ditch’s own bottom also extends the excavation envelope: quantities’ Excavation (to formation) figure counts everything down to the ditch invert on an active ditch, not just to the pavement datum, since a ditch is simultaneously a finished-surface feature (it’s what you see) and a formation feature (it’s what has to be dug). A ditch row draws as an open outline (no fill) using its own outline-colour slot in the section style’s Corridor tab, alongside Lane/Shoulder/Median/ Curb/Sidewalk/Slope/Generic.

5.7.5.3. Benching

Tall daylights no longer walk a single uninterrupted slope face all the way to the ground: a Slope row can now specify benching separately for its cut branch and its fill branch, each a triple of MaxHeight / BenchWidth / BenchSlope edited in the row params dialog (double-click a Slope row’s P column). Leaving MaxHeight at its default of 0 disables benching for that branch — the daylight behaves exactly as before.

With benching enabled, the resolver walks the active branch’s slope for at most MaxHeight of vertical rise/fall; if the ground crossing is found inside that lift, the ordinary daylight point closes the chain there (to the usual 1 mm tolerance) and benching never engages for that station. If the ground is not yet reached, the daylight instead breaks outward: a bench point at the lift’s top, walking BenchWidth outward at BenchSlope to a second bench point, then the next lift starts from there. Named points appear along the way — DL.B1, DL.B1E, DL.B2, DL.B2E, … — one pair per completed lift, so section views and feature lines carry a distinct point per bench. Lifts repeat until the ground is met; a hard cap of 20 lifts stops the walk and flags that station Ungraded on the command line rather than looping forever on pathological ground.

The Assembly Editor’s preview draws one schematic bench break — a single jog partway along the branch’s daylight stub — whenever a branch’s MaxHeight is non-zero, as a reminder that benching is active; the preview’s flat test ground can’t show a real multi-lift walk, so the schematic jog is deliberately just an indicator, not a solved bench chain.

5.7.5.4. The excavation-edge hinge fix

Both the cut and the fill daylight now spring from the end of excavation — the outer bottom corner of a side’s outermost course stack, exactly where the excavation-to-formation envelope actually ends — rather than from the shoulder’s finished top edge as before. Previously the daylight point anchored to the row chain’s top link, which sits above and inboard of a widened subbase or a taper foot; because those courses are authored wider than the row itself (see “Pavement structure” above), the true excavated face reached further out than the daylight line implied, undercutting it. Anchoring to the excavation edge instead means the daylight — and any ditch feeding into it — starts exactly where the dig actually stops.

A short connector link closes the gap down the outermost course stack’s outer face (from the row’s top point to the excavation-edge point) so the Top chain stays continuous for area and silhouette purposes; on a side with no course stacks at all (e.g. a bare Generic or Median row feeding straight into a Slope), there is no excavation edge to speak of and the daylight falls back to anchoring at the row’s own top point, exactly as before this fix.

This is a bug fix, not a new option — every assembly with course stacks on its outer rows sees its daylight (and, if you add one, its ditch) start slightly further out and down than in earlier releases; unconditional daylight-only assemblies otherwise resolve bit-identical geometry.

5.7.5.5. Upgraded standard templates

All six templates in standard-roads.iqal (Rural-Narrow-2x3.0, Rural-2x3.5, Urban-2x3.5+walks, Urban-Boulevard-2x2x3.25, Highway-2x2x3.5+median, Freeway-2x3x3.75) now carry, on each side, immediately before the closing Slope row:

A Cut-only ditch — Depth 0.5 m, BottomWidth 0.5 m, ForeSlope 1:2, BackSlope 1:1.5.
Benching on both branches of the Slope row — 5 m lifts, 1.5 m benches, 4% bench slope.

Note

On Urban-2x3.5+walks and Urban-Boulevard-2x2x3.25 the ditch ends up sitting behind the sidewalk (Lane → Curb → Sidewalk → Ditch → Slope) — a cut-drainage ditch with no shoulder buffer ahead of it, which is unusual civil practice for an urban street. This is a literal application of “the ditch goes between the last row and the slope on each side” to templates that have no shoulder; the other four templates place the ditch after a shoulder, which reads normally. Review this per project: edit the ditch’s parameters, move it, or delete the row entirely on a copy of these two templates if a project doesn’t want cut drainage immediately behind its pedestrian walk.

5.7.5.6. Persistence

Row condition, ditch parameters, and both branches’ bench parameters round-trip through .iqal (and the equivalent IQML) exactly like every other row field: an unconditional row omits the condition attribute entirely (so pre-Phase-5 files still load with every row defaulting to Always), a Ditch row always writes its four ditch attributes, and a Slope row writes each of its six bench attributes only when non-zero. This is an additive extension of the existing v2 schema — no version bump was needed.

5.7.6. Standard sample library

IQcad ships six pre-authored road templates in standard-roads.iqal (under testdata/library/ in the distribution). An empty drawing’s assembly library auto-loads them the first time you open Civil › Assemblies… or run BUILDCORRIDOR — no manual import step is needed. You can also seed them on demand with SAMPLEASSEMBLIES (alias SAS), which is idempotent: assemblies that already exist by name are skipped. The Import button in the Assembly Editor remains available for loading additional/custom .iqal files from elsewhere.

5.7.6.1. Rural-Narrow-2x3.0

Low-traffic backroad. Narrow lanes and shoulders with relatively steep slopes — appropriate for mountain roads, forest tracks, and single-family rural access.

../../_images/sample_rural_narrow.png — Rural-Narrow-2x3.0 cross-section.

When to use it. Low-volume rural backroads where right-of-way is constrained and design speed is low (under 50 km/h).