Cities: Skylines

Cities: Skylines

1,628 ratings
Roundabout Builder
File Size
0.079 MB
Jan 15 @ 9:24am
Aug 12 @ 5:53am
19 Change Notes ( view )

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Roundabout Builder


Experiencing issues? Reinstall (resubscribe) this mod

Any ideas how to make this mod even better? Post them to the discussions section.
Did you encounter any odd behavior? Please report it as soon as possible! It may be caused by the new update(s) and I might not know about it.

This mod automatically builds roundabouts for you. It clears the area of the roads and snaps them onto the roundabout. Road anarchy is recommended.

How to use this mod?

(1) Enable this mod in content manager

(2) When in game, press CTRL+O or click the icon in road tools menu

(3) A small window should appear. Hover over an intersection and you should see a red circle representing the roundabout to be built (inner line of the circle = inner edge of the road and vice versa). Click and the roundabout will be built
If you want to build the roundabout with roads automatically connected, make sure that you stay in the main menu! Don't click 'Free Cursor', 'Elliptic roundabout' or anything

Before building the roundabout
(4) You can change the radius by editing the value in the window or by pressing +/-
(Warning: the road will be very distorted if the radius is too low. You should not go under 15 units)

(5) You can change the roundabout road in the dropdown menu or by selecting the road in the roads menu (works only for one-way roads by default). After you clicked on the road in the roads menu, click anywhere in the window to reselect the roundabout tool

Any time the tool is unselected while the window is open, click anywhere in the window to reselect it.

Check the "Keep open" box so that the window doesn't close automatically when the tool is unselected

Elliptic roundabouts

That is a bit more complicated, follow the instructions in the window.
Big note: Unlike from standard circular roundabouts, the elliptic ones can be only approximated in the game. The shape of the ellipse is affected by the location of points where the roads cross the ellipse. If the road layout is asymmetric, the shape of the ellipse will be deformed. If that happens, consider building the roundabout first and after that connecting some of the roads.
Control points on/off - when the option is turned on the mod will insert four controlling nodes at the points where the main and minor axes cross the ellipse to keep it in shape. See a screenshot above. When there are roads exactly at the positions of the axes this option has no effect.

TMPE Policies

If you are using Traffic Manager, this mod automatically sets some policies for you. These include: No parking, Priority signs, ability to enter blocked junctions and disabling crossings. You can disable this feature as a whole or allow the policies one-by-one.
Warning! If you use local version of TM:PE, it must be located in a folder called 'TrafficManager', otherwise this feature won't work.

Road snapping algorithm

From version BETA 1.1.0, there is a new snapping algorithm. To change the algorithm go to options.
Standard - Respects the direction of the road when snapping it to the roundabout. Connects it at whatever angle the road is.
Old - Distorts the road, but connects it at 90° angle. More reliable.
Well, I wanted to create an algorithm that would take the best from the methods mentioned above, but for now it turned out to be too complicated. Or I am just lazy.

Tips & Tricks

With this mod you can create super cool mini roundabouts (common in some parts of the world) as seen on these screenshots[]. Underneath is a standard roundabout with radius of five units upgraded to a highway ramp. Onto it I moved some tiling with Move It because the roads appear glitched when the radius is so small.

Is it possible to build power lines, cable car wires and other structures that are not roads with this mod? Yes it is! Just go to settings and tick the 'Do not filter prefabs' option. Then every available prefab (linear structure) will appear in the menu.

How to build elevated roads? You can force roads to elevated mode by using Fine Road Tool. Warning: If you are using a local version of FRT, make sure it is placed in a folder called 'FineRoadTool'.

Important note!

You use this at your own risk! Intended only for flat ground without buildings! Don't use on places like an edge of the map.

Before using for the first time, try it at some place where it can't cause much damage. If you try to break this mod, you very easily can.

Source code & credits

Source code[]

Big thanks to boformer for his tutorials on Simtropolis, to Elektrix from whom I took some source code and for his advice. As well as that, I copied bigger or smaller parts of the code from: Parallel Road Tool by T__S, Move It!, Fine Road Tool and Button shortcuts by SamsamTS, Crossings by Spectra, TMPE and probably others.

Check out my other work as well!
Smart Intersection Builder Mod
Adjust Pathfinding Mod

Please leave any feedback below!
Popular Discussions View All (8)
Aug 10 @ 11:12am
PINNED: Bug reports
Jul 4 @ 6:05pm
Jun 2 @ 10:38am
Suggestion: +/- shortcut
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Megatix 5 hours ago 
This is great!
Would you be able to add an tilt option.
For example I've built an roundabou that went down the earth had an terrain part and went up as a bridge to then come back to the ground again, all that for a road to pass right through it, like in a needleeye. ^^

Tell me what you think.
rastaban99 11 hours ago 
+1 it desappear in game ctrl+O not work sub/unsub no solve that ! Enable Desable not work
SoNotCool 16 hours ago 
@Strad , yes shows and works with shortcut, but some reason my little icon has left
Strad  [author] Aug 23 @ 12:59pm 
@SoNotCool Does it appear in content manager? Does the shortcut work (CTRL+O)? Thanks!
SoNotCool Aug 23 @ 9:15am 
did something break with Roundabout Builder, it has not been working on my Cities install for a month now.. I continue to do the Sub/UnSub thing but to no avail...
Strad  [author] Aug 10 @ 7:26am 
In the main menu there is something like "0 / X mods enabled". Click that and you will see a menu, in which you can enable the mods.
ervada66 Aug 10 @ 6:03am 
and other mods btw.. playing for a few days now so i am totally green...
ervada66 Aug 10 @ 6:02am 
maybe a stupid q... how do i get the mod working in the game?
Strad  [author] Aug 8 @ 10:07am 
It's nice you let me know because I hoped that it doesn't happen anymore. Anyway, I am happy that the mod makes you happy :D
Cago™². Aug 8 @ 10:04am 
Thank you, I dont mind the icon bug/problem. I just thought about letting you know since it worked the first time I downloaded the mod. Great mod btw, cant live without it now.