From centreline to road.
Select the plan lines, type the elevations you know, press Build. Roadbox turns them into a 3D road surface inside SketchUp — lanes, kerbs, sidewalks, medians and junctions that actually fit — in one Undo step.
The network as Roadbox sees it: your centrelines, the surfaces it builds on them, and the elevations you typed at the ends and junctions.
Three steps, no modelling. Your lines stay yours; Roadbox builds next to them.
Roadbox reads the centrelines you already have — CAD import, hand-drawn, arcs, polylines — and never edits them. Everything it makes lives in its own group with a single Undo.
Select the centrelines
Pick the edges on the plan and press Create network. Crossings become junctions, a polyline or arc is one road, small drawing gaps are closed for you.
Elevations and cross-sections
Type the elevations at the points you know — road ends and junctions. Everything in between interpolates. Assign a named cross-section to any road.
Check, then build
Check previews the outlines on the plan and lists anything that does not fit, with the fix on a button. Build writes the surface — one Undo step.
Built for how road designers actually work.
Every picture below is the real panel, on a network the engine built.
Roads and junctions, in two lists.
A road runs from one junction to the next; a junction is where roads meet. Each road shows its length, grade, start and end elevation, cross-section and transition. Each junction takes one radius. Nothing to hunt for, nothing named after a vertex.
Your own cross-sections.
Lanes, shoulders, bike lanes, sidewalks with kerbs, raised medians — as many named profiles as you like, symmetric or not, assigned per road. Kerb heights and crossfalls are yours; the live section shows what you typed.
Elevations where you know them, grades everywhere else.
Type an elevation at a road end, a junction, a point you surveyed — and only there. Everything between interpolates; every grade break gets a vertical curve; every junction sits on a plane that fits all its arms, and each road eases back to its own grade over a transition you set.
Problems, explained — with the fix on the button.
Nothing fails silently. Whatever does not fit is listed in plain words, one line per kind, marked on the plan. Open the detail and the fix is a button: set this radius to 14 m, join this loose end to that road, make this crossing a junction. A wizard walks you through them one at a time, showing each result in yellow before you commit.
Place junctions where you want them.
Click a road on the plan to put a junction there; click a bend to make it a junction or a through point again. Add elevations the same way. The plan is the drawing board — the model updates when you build.
Everything in the box.
One extension, one panel. No add-ons, no modules.
Any centreline
Lines, polylines and arcs from CAD or drawn by hand. One edge of a curve selects the whole curve; gaps and near-misses are closed within a tolerance you set.
Elevations and vertical curves
Type elevations only where you know them. Grade breaks get a parabolic vertical curve with a length you control; short arms shorten it automatically.
Named cross-sections
Lanes, shoulders, bike lanes, sidewalks with kerbs, raised medians. Symmetric or not. Assign a profile per road; the section preview updates as you type.
Junctions with one radius
Three-arm, four-arm, T and Y. One radius per junction on the outer edge — or corner by corner when you need it. The plane fits every arm, or you pick the main road.
Problems in plain words
A summary first, the detail on request. Each item says what, where and why, is marked on the plan, and carries its fix as a button. Skip what you mean to leave.
Network fixes, not manual surgery
A loose end that stopped short of a road? Two lines crossing without a node? One click joins the tip, makes the crossing a junction, or collapses a stray sliver.
Fold two networks into one
Two Roadbox groups in one model? Select both and fold the second into the first: shared nodes join, crossings become junctions, profiles and elevations come along.
Revise without redoing
Changed the centreline? Select the revised lines and update. Profiles, elevations, radii and per-road settings are matched by position and kept.
Clean SketchUp geometry
Real faces, softened edges, one material per strip, everything in one group. Your source lines are never touched; the surface rebuilds in a single Undo step.
It sits beside your model, not in the way.
This is the actual panel, running on a demo network. Click around: select a road, open a junction, try the tools.
English and Turkish, switchable in the panel.
Get Roadbox
Start with the trial. It is the whole product for three days — no card, no form.
Trial
- The whole product, not a preview.
- No card, no sign-up form.
- Once per computer.
Standard
- One person; install on your computers, one SketchUp open at a time.
- 72 hours offline after the last check-in.
- Every update while you subscribe.
- Cancel anytime.
Questions people ask first
Which SketchUp versions are supported?
SketchUp 2022 and newer, on Windows and macOS.
What do I need to draw first?
Only the centrelines, on a horizontal plane, at the model root — lines, polylines or arcs, from CAD or by hand. The plane may sit at any height; Roadbox keeps its guides there. Elevations are typed in the panel, not drawn.
Does it change my drawing?
No. Your lines are read, never edited, exploded or moved. Everything Roadbox makes goes into its own group, and every build is one Undo step.
Which junctions can it build?
Two-arm bends, T and Y junctions and four-arm crossings, at any angle. Each corner is a true tangent arc on the outer edge; sidewalks and kerbs continue around it. Five or more arms, and very shallow merges, are not supported yet — they are reported, not guessed.
What happens when something does not fit?
The rest is still built. The problem is listed in plain words, marked on the plan, and the fix is a button. You can also let Roadbox shrink radii and transitions automatically and tell you what it changed.
On how many computers can I install one licence?
Install it on your computers; one SketchUp may hold the licence at a time. The licence code is the account — enter it once on each machine.
Does it work without an internet connection?
For 72 hours after the last successful check-in. Without a licence the panel still opens, reads networks and runs Check; only Build is locked.
Can I get a refund?
Fourteen days, no reason needed — write to us and we refund the charge in full. There is also the free trial, so you can find out before paying anything. See refunds & cancellation.
How do I cancel?
Open the subscription-management link at the bottom of any receipt Paddle sent you, or write to us and we will do it. You keep access to the end of the period you have paid for.