Cities: Skylines

Cities: Skylines

8,595 ratings
Roundabout Builder
File Size
0.101 MB
Jan 15, 2019 @ 9:24am
Sep 28 @ 5:08am
42 Change Notes ( view )

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Roundabout Builder

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


Experiencing issues? Reinstall (resubscribe) the mod

If you cannot run this mod at all (icon is not showing and shortcut is not working), you can try Extended Error Reporting Mod and Mod Compatibility Checker to find if another broken mod isn't causing the trouble.
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.

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

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, ability to change lanes at 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

You can also try Automatic Pedestrian Bridge Builder mod, which makes building overpasses over roundabouts and intersections as easy as two clicks.

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.

Why did the option to build elliptic roundabouts disappear? Elliptic roundabouts are now deprecated, but you can enable them in the options. See this tutorial on elliptic roundabouts[]

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/RA, make sure it is placed in a folder called 'FineRoadTool'/'RoadAnarchy'.

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.
Respect to all the boulders without which no roundabout would be complete!

Check out my other work as well!
Smart Intersection Builder Mod
Undo It! Mod
Python Console Mod

Address: bc1qvma38p2fcgle9z0w3dehljjt303r4q2qg89nqy

Please leave any feedback below!
Popular Discussions View All (24)
Oct 1 @ 11:49am
PINNED: Bug reports
May 8 @ 12:40am
TM:PE Integration
Dec 25, 2021 @ 11:57am
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Jamie Dec 8 @ 9:15am 
Love this mod. Thank you!
LemonsterOG Dec 5 @ 8:17am 
@Momma_1 -- It IS compatible. You can ignore the message.
Momma_1 Dec 3 @ 9:57am 
my game says this is incmptible, but i also don't see it on the spreadhseet??
LemonsterOG Dec 3 @ 7:29am 
@jimtduffy -- You can also post what you think you found on the Compatibility Report page for response.
LemonsterOG Dec 3 @ 7:26am 
@jimtduffy -- They may *look* like they're working not he surface, but you don't know what's happening behind the scenes. If you're going to use incompatible and/or broken mods, please do not ask for help on any mod pages.
Fenris Valren Dec 2 @ 3:17pm 
@jimtduffy This mod works without any problems for me, but I did start a new game. Try creating a fresh game to see if it works.
jimtduffy Dec 2 @ 1:25pm 
Unfortunately, Lemon, the compatibility report contains some errors - as I found out in testing out mods. I removed all contents of 255710, then re-inserted them individually (along automatically with the critical files like, for example, harmony) and ran the game. Most mods described in the report worked as it said. Some didn't. Some it said was compatible immediately crashed the game, which worked when they were removed. Others, like this one, would not show up despite supposedly being compatible. Others described as incompatible, or broken, did work.

The compatibility report is superb, but unfortunately not infallible. Given the sheer scale of problems the update caused (way more than any previous update), it was a mammoth task to analyse all the mods on the system. I admire the work done enormously. It is hardly surprising for mistakes to occur. Even Homer nods.
LemonsterOG Dec 2 @ 8:13am 
@jimtduffy -- A lot of mods are now broken, but this is NOT one of them.

Please share your Compatibility Report and Output Log for troubleshooting.

IMPORTANT: Click here for additional help and instruction.
jimtduffy Dec 1 @ 2:28pm 
It doesn't seem to be working since the new update. I have had hell getting the game to work since the update. I only just got it to work last night, only to notice a couple of mods, including this one, aren't working (and they are definitely subscribed and turned on). The update seems to have broken a vast number of things. I don't remember any other update causing so much trouble. I didn't get the dlc or want it. I really wish they would stop having so many updates. They cause chaos.
Fenris Valren Dec 1 @ 11:21am 
@olgastelter must be some incompatibility with other mods. It works fine for me with multiple mods installed