How to grade intersections perfectly on the sketchup?

SketchUp
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1

Hi everyone,

I’m trying to model an urban road layout on a sloped terrain in SketchUp, similar to the attached image.

My main difficulty is not modeling the terrain itself, but creating the road surfaces correctly where different slopes meet.

In one direction, the road follows a longitudinal slope, going uphill/downhill. But in the transverse direction, the road also needs a cross slope/camber for drainage. The hardest part is where two roads or streets intersect, because the longitudinal grade, cross slope, road crown, curbs, sidewalks and terrain all need to transition smoothly.

I believe this is related to terms like:

  • intersection grading

  • road crown transition

  • cross slope transition

  • pavement warping

  • cut and fill / daylighting

  • road corridor modeling

Is there a good workflow in SketchUp for modeling this kind of road intersection on sloped terrain?

I’m especially looking for an advanced method, not a basic Sandbox terrain tutorial. I would like to understand how to build the road surface, curbs, sidewalks and surrounding terrain so the slopes meet correctly and the geometry looks realistic.

Would you recommend using native SketchUp tools, Sandbox, Artisan, Vertex Tools, Curviloft, Fredo tools, or another extension/workflow?

Any tutorials, examples, plugins, or workflow suggestions would be very helpful.

Thanks!

image
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2

I’d 1000% recommend investing in the Landshape extension by Holygon. I recently did a test run of it on a mountainous road - complete with retaining walls transitions, sidewalks, road centerlines etc. https://www.youtube.com/watch?v=A5NIiTbzqRI

3

I use vertex tools when I try to do something like that, it has flatten tool that I use it with a smoothing radius to make the transitions between flat and the organic shape of the terrain look natural.

4

Or look at Valiarchitects “Instant Roads” on the extension warehouse.. here is a link to a project 10 years ago using the extension

https://3dwarehouse.sketchup.com/model/37472851-08f1-4eae-83ac-f8b2f0f3e5d7/TOPOGRAPHY-MODEL-WITH-ROADS

5

I agree with @eric-s . The best extension to model that terrain is Landshape.

6

teren-03.skp (200.4 KB)

I created a terrain with a certain road configuration so that different extensions can be tested, if you want to try. The road must be “flat and horizontal”, similar to a real one.

teren-03
teren-031215×879 128 KB

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I know, it looks like pretty, but isn’t real life applicable. The car that’s will follow the road can’t drive on that road. I need something more professional.

8

You misunderstood the post. :slight_smile:
When someone asks for help, it would be useful to also provide an SKP model so that those who can help them don’t start guessing what the model looks like from the description or picture and don’t have to recreate it to be able to test solutions to offer.
Knowing this, I created a model and made it available to those who want to offer solutions.

:fast_forward_button: teren-03f.skp (650.9 KB)

A model created using extensions: yol_duzenleyici (by @kenancakir), Select Curves, Vertex Tools, Artisan, Fredo Curviloft, Fredo Spline, Fredo ThruPaint.

teren-03f
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teren-03f2
teren-03f21331×828 161 KB

Once you have the model properly prepared, you can then add the necessary details (road drainage slopes, sidewalks, curbs, etc…).

See discussions about roads here - Hobby mihai.s - #434 by mihai.s

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Adding details to roads and terrain