# A New Approach to the Roundabout - The Pinwheel ![[images/A-New-Approach-to-the-Roundabout-The-Pinwheel.webp]] **Creator:** YUMBL (@YUMBL / YUMBLtv) · **Published:** 2021-11-05 · **Length:** 12:52 · [Watch on YouTube](https://www.youtube.com/watch?v=zvcyRsMZkg4) > Caption source: YouTube English auto captions via `youtube-transcript-api` after yt-dlp subtitle downloads returned HTTP 429 (android_vr client, then spaced retries with sleep, then web client). ASR quirks include "yumble"/"Yumblecorp" for **YUMBL** / **YUMBLcorp**, "nest" once for **mess**, and "make n straight" for **Make Ends Straight**; outline uses intended spellings. Timings follow the caption stream and the chapter list in the video metadata. Screenshots from the downloaded video. Added from the user's "Summarize" playlist. ## Outline ### Intro ([0:00](https://www.youtube.com/watch?v=zvcyRsMZkg4&t=0s) to 1:11) - [0:00](https://www.youtube.com/watch?v=zvcyRsMZkg4&t=0s) Hook: "roundabout day" at **YUMBLcorp**; today's subject is a design sent via Twitter by **William J** (YUMBL says he recently retweeted it). - [0:16](https://www.youtube.com/watch?v=zvcyRsMZkg4&t=16s) William also supplied a **triangular** version; YUMBL chose the four-leg pinwheel to render in-game. - [0:23](https://www.youtube.com/watch?v=zvcyRsMZkg4&t=23s) Naming: **pinwheel roundabout** — the empty pavement wedges look like a spinning pinwheel toy. - [0:38](https://www.youtube.com/watch?v=zvcyRsMZkg4&t=38s) Geometry pitch: nodes still sit on cardinal N/S/E/W axes, but roads split off so **right-turning traffic never really knows it is in a roundabout**. - [0:58](https://www.youtube.com/watch?v=zvcyRsMZkg4&t=58s) Caveat: lane math is "up to interpretation"; goal is to get the Twitter schematic into **Cities: Skylines**. ![[images/A-New-Approach-to-the-Roundabout-The-Pinwheel-t0005.webp]] *Opening schematic: four-leg pinwheel / turbo-variant plan sent by William J* ![[images/A-New-Approach-to-the-Roundabout-The-Pinwheel-t0020.webp]] *Same pinwheel plan with lane dividers emphasized — right-turn bypasses as pinwheel "blades"* ### Forbidden Knowledge ([1:12](https://www.youtube.com/watch?v=zvcyRsMZkg4&t=72s) to 5:20) - [1:12](https://www.youtube.com/watch?v=zvcyRsMZkg4&t=72s) Full disclosure: an entire first take was ruined by missing audio; this cut is a second build with prior experience ("forbidden knowledge") rather than live muddling. - [1:38](https://www.youtube.com/watch?v=zvcyRsMZkg4&t=98s) Base: favorite **5×5** roundabout — five grid units down, five over, repeated around the circle. - [1:52](https://www.youtube.com/watch?v=zvcyRsMZkg4&t=112s) **Fine Road Anarchy** required; angles are too tight for vanilla. He has moved away from Network Extensions 2 toward **Big Urban Roads** one-lane alley segments. - [2:23](https://www.youtube.com/watch?v=zvcyRsMZkg4&t=143s) With anarchy on, from each roundabout node build **perpendicular** arms: five units out and five over (opposite of the circle construction), then **ten units** across the far side so each approach has mirrored five-unit wings. - [3:06](https://www.youtube.com/watch?v=zvcyRsMZkg4&t=186s) The resulting nest of overlapping textures is intentional — "the mess is necessary." - [3:48](https://www.youtube.com/watch?v=zvcyRsMZkg4&t=228s) Tease: Intersection Marking Tool work will be the most complex finishing pass. - [4:03](https://www.youtube.com/watch?v=zvcyRsMZkg4&t=243s) Why it looks broken: a fully straight road hits a roundabout node **perpendicularly**; the game is not programmed for that texture case. - [4:23](https://www.youtube.com/watch?v=zvcyRsMZkg4&t=263s) Connect consistent Big Urban Roads first (two-lane center ring context + one-lane alley arms); connect arm ends before finishing approach roads. - [4:53](https://www.youtube.com/watch?v=zvcyRsMZkg4&t=293s) Contrast with a normal four-leg roundabout that hits the circle dead-center on the cardinals; this design is **offset to the side** of the circle — the visual hook. ![[images/A-New-Approach-to-the-Roundabout-The-Pinwheel-t0072.webp]] *Schematic overlaid on the Cities: Skylines sandbox as the build begins* ![[images/A-New-Approach-to-the-Roundabout-The-Pinwheel-t0100.webp]] *"Forbidden knowledge" beat: second take after a silent first recording* ![[images/A-New-Approach-to-the-Roundabout-The-Pinwheel-t0140.webp]] *Starting the 5×5 cardinal roundabout with Fine Road Anarchy enabled* ![[images/A-New-Approach-to-the-Roundabout-The-Pinwheel-t0260.webp]] *Perpendicular anarchy arms creating the pinwheel nest of clipped textures* ### Fix the Clipping ([5:21](https://www.youtube.com/watch?v=zvcyRsMZkg4&t=321s) to 8:18) - [5:21](https://www.youtube.com/watch?v=zvcyRsMZkg4&t=321s) Tool: **Node Controller Renewal** (latest Node Controller; he has a separate video on it) — used here mainly to nudge roads into place. - [5:45](https://www.youtube.com/watch?v=zvcyRsMZkg4&t=345s) Where two roads share one node center, **shift-click** far-left and far-right edges to align each with its own half of the incoming road, then **Make Ends Straight**. - [6:34](https://www.youtube.com/watch?v=zvcyRsMZkg4&t=394s) Extra trick: after aligning one pair, align the adjacent segment outward so the angle becomes more favorable; chase that angle all the way around ("we've come full circle"). - [7:41](https://www.youtube.com/watch?v=zvcyRsMZkg4&t=461s) Reminder: shift-click is the workhorse for edge alignment. - [7:57](https://www.youtube.com/watch?v=zvcyRsMZkg4&t=477s) Preview of the texture fix: the true cure is dragging each network off a perfect 90° — covered next with Move It — after Make Ends Straight equalizes ends. ![[images/A-New-Approach-to-the-Roundabout-The-Pinwheel-t0321.webp]] *Node Controller Renewal: shift-click edge alignment on a clipped pinwheel node* ![[images/A-New-Approach-to-the-Roundabout-The-Pinwheel-t0360.webp]] *Make Ends Straight and successive corner alignments chasing the pinwheel angle* ### Nudge It ([8:19](https://www.youtube.com/watch?v=zvcyRsMZkg4&t=499s) to 10:52) - [8:19](https://www.youtube.com/watch?v=zvcyRsMZkg4&t=499s) Switch to **Move It**: select each right-turn / exit segment, hold **Ctrl**, drag a hair off 90°; textures "fix as if by magic." - [8:47](https://www.youtube.com/watch?v=zvcyRsMZkg4&t=527s) Apply to all four exits — composition barely changes; only the overlap with the roundabout ring is broken. - [9:07](https://www.youtube.com/watch?v=zvcyRsMZkg4&t=547s) Same Ctrl-nudge on remaining clipped segments (<1 meter / <1 unit). - [9:30](https://www.youtube.com/watch?v=zvcyRsMZkg4&t=570s) General tip: Move It + Node Controller together fix many "nice but clipped" builds. - [9:44](https://www.youtube.com/watch?v=zvcyRsMZkg4&t=584s) Re-run Make Ends Straight after Move It (or wait until the end — Move It can disturb ends). - [10:05](https://www.youtube.com/watch?v=zvcyRsMZkg4&t=605s) No custom Node Controller numeric offsets typed — only shift-click align + Make Ends Straight + micro nudges. - [10:22](https://www.youtube.com/watch?v=zvcyRsMZkg4&t=622s) Shape locked; he steps away briefly to explore lane math and Intersection Marking Tool decorations for the finished product. ![[images/A-New-Approach-to-the-Roundabout-The-Pinwheel-t0499.webp]] *Move It: Ctrl-drag a right-turn segment off 90° to clear texture clipping* ![[images/A-New-Approach-to-the-Roundabout-The-Pinwheel-t0530.webp]] *Repeating the sub-meter nudge on each pinwheel exit arm* ### There Ya Have It! ([10:53](https://www.youtube.com/watch?v=zvcyRsMZkg4&t=653s) to 12:52) - [10:53](https://www.youtube.com/watch?v=zvcyRsMZkg4&t=653s) Finished reveal: landscaped islands with benches, seats, trash cans; crosswalks set back from the circle and linked by paths through small park wedges. - [11:16](https://www.youtube.com/watch?v=zvcyRsMZkg4&t=676s) Honesty check: walkability is a roundabout weak point — pedestrians walk farther than at a tight intersection — but paths make this case usable. - [11:36](https://www.youtube.com/watch?v=zvcyRsMZkg4&t=696s) Throughput choice: **two-lane** roads in and out — left lane enters the circle; right lane continues as a bypass into the next right lane, keeping entering and exiting streams separated. - [11:43](https://www.youtube.com/watch?v=zvcyRsMZkg4&t=703s) Self-critique: not as optimal as a true **turbo roundabout**, but strong throughput from lane separation and a distinctive look that invites park land uses. - [12:21](https://www.youtube.com/watch?v=zvcyRsMZkg4&t=741s) Markings took time; build was fun. CTA: Discord, Twitch streams, subscribe (usually ~two videos/week). Sign-off as Yumble. ![[images/A-New-Approach-to-the-Roundabout-The-Pinwheel-t0653.webp]] *Finished pinwheel with park islands, paths, and set-back crosswalks* ![[images/A-New-Approach-to-the-Roundabout-The-Pinwheel-t0680.webp]] *Landscaped wedges and path network around the offset four-leg circle* ![[images/A-New-Approach-to-the-Roundabout-The-Pinwheel-t0720.webp]] *Traffic running the two-lane approach / right-turn bypass configuration* ## Things Mentioned ### People - **YUMBL** (on-camera "Yumble"; YUMBLtv / YUMBLcorp) — host and builder - **William J** — Twitter correspondent who sent the pinwheel schematic (and a triangular variant); full legal name not given ### Places / platforms - **Cities: Skylines** (Colossal Order / Paradox) — build sandbox for this video - **Twitter** — source of the schematic; YUMBL's handle linked in description as twitter.com context for YUMBLtv - **Steam Workshop** — post-publish home for a later reversed-visibility version of the design (description link `?id=2646965873`) - **Twitch** (yumbltv) and **Discord** — community CTAs - **Patreon** (yumbltv) — support link in description ### Designs / concepts - **Pinwheel roundabout** — YUMBL's name for this offset four-leg layout (empty wedges resemble a pinwheel) - **Turbo roundabout** (real-world Dutch/FHWA family: spiral multilane roundabouts with physical lane separation) — cited as the more optimal reference this Cities: Skylines build does not fully match - **5×5 cardinal roundabout** — his preferred starter circle (five grid units per cardinal leg) - Right-turn **bypass / slip** behavior — right-turning traffic stays out of the circulating roadway - Pedestrian **set-back crosswalks** + park path wedges ### Mods / tools (on-screen + description) - **Fine Road Anarchy** (Steam Workshop `1844440354`) - **Node Controller** / **Node Controller Renewal** (Workshop `2472062376`) - **Move It** (Workshop `1619685021`) - **Intersection Marking Tool** (Workshop `2140418403`) - **Big Urban Roads** one-lane alley roads (preferred here over Network Extensions 2) ### Books and texts - None named. ## Biographies ### YUMBL American Cities: Skylines (and later Cities: Skylines 2) YouTuber and Twitch streamer behind **@YUMBL** / **YUMBLtv** (channel created **22 Apr 2020**; ~91–92k subscribers and ~150+ videos as of late 2026 public listings). Channel focus is traffic solutions, intersections, interchanges, and road planning, with a jokey "YUMBLcorp" persona; also streams live and maintains Discord/Patreon communities. This 2021 video is a first-game (Cities: Skylines) modded roundabout tutorial; later channel copy emphasizes Cities: Skylines 2 traffic work. ### William J Only identified in the video as the Twitter user who sent the pinwheel schematic (and a triangular companion). No further public bio is given on-camera; treat as a community tipster rather than a named traffic engineer. ## Claims Check | Claim | Verdict | Notes / source | | --- | --- | --- | | Design came from Twitter user William J; a triangular variant also existed ([0:07](https://www.youtube.com/watch?v=zvcyRsMZkg4&t=7s)) | Unverified primary | Relies on host statement; tweet not archived in this note. | | Right-turning traffic can bypass without "knowing" it is in a roundabout ([0:51](https://www.youtube.com/watch?v=zvcyRsMZkg4&t=51s)) | Directionally sound as geometry intent | Matches slip-lane / turbo-style channelization ideas: dedicated right turns stay outside circulating lanes. In-game AI and real drivers still read the junction context. | | Vanilla Cities: Skylines cannot place these tight anarchy angles ([1:57](https://www.youtube.com/watch?v=zvcyRsMZkg4&t=117s)) | Plausible for CS1 | Fine Road Anarchy / similar anarchy mods are standard community tools precisely to override vanilla node/angle limits. | | Perpendicular road-into-roundabout-node textures are unsupported and clip ([4:08](https://www.youtube.com/watch?v=zvcyRsMZkg4&t=248s)) | Accurate as CS1 behavior | Widely reported CS1 limitation; Move It micro-offsets and Node Controller end fixes are common community workarounds, matching the demo. | | Finished build is "not as optimal as a turbo roundabout" ([11:45](https://www.youtube.com/watch?v=zvcyRsMZkg4&t=705s)) | Fair self-assessment | Real **turbo roundabouts** (Dutch CROW / FHWA family: spiral circulatory lanes, raised lane dividers, reduced weaving) are a specific engineered class; this CS1 pinwheel is an inspired visual/traffic-separation variant, not a full turbo template (egg/basic/knee/spiral/rotor). | | Separating entering vs exiting streams improves throughput ([12:01](https://www.youtube.com/watch?v=zvcyRsMZkg4&t=721s)) | Directionally supported | Consistent with multilane roundabout guidance that reducing weave conflicts raises capacity/safety; quantitative CS1 throughput not measured in the video. | | Description: design later reversed for better driver visibility and uploaded to Steam Workshop | Supported by description | Workshop link in description (`sharedfiles/filedetails/?id=2646965873`); "reversed" change is author-stated, not demonstrated in this cut. |