jesse
c297b20aed
Three iterations of the Daikoku PA ramps never read as a real
interchange. Measured why, rather than tuning further:
* the entry and exit decks INTERSECTED -- 2547 sample pairs within
30 studs horizontally at <12 studs dY, worst case 0.5 studs apart
at dY=0.0. On screen that is the bowtie tangle of white rails.
* both real Daikoku ramps turn the SAME way (clockwise; the guide
video says "right, right"). This build mirrored them into each
other.
* the real arc wraps OUTSIDE the lot and forms its north/east
boundary. This build cut across the apron interior.
Gated behind BUILD_PA_RAMPS=false rather than deleted -- the radius
was already correct (470 studs vs an OSM-measured mean of 469) and
the merge lands tangent at 0.1-0.2 deg divergence. Both worth keeping.
Also removed two leftovers that would have outlived the ramps:
* rampOpen punched holes in the mainline's outer parapet, railing
and kill wall for ramps that no longer exist -- a barrier gap with
a drop behind it. Sealed via RAMP_EDGE_OPENINGS=false. Verified:
Barrier/EdgeRail/KillWall = 1646 each = 823 samples x 2 edges,
0 road samples without a guard within 90 studs.
* gore zebra hatching painted 1024 bars + 64 boundary lines marking
a junction that is not there. Sealed via RAMP_GORE_MARKINGS=false.
Verified after a cache-busting fresh rebuild (Studio's require() cache
otherwise serves the previous map and reports a false pass):
parts 22628 -> 15988
all ramp part classes = 0
Road = 823 (unchanged), spawn pad + PASpawn intact
clip probe TRUSTWORTHY (control +11/-0), CLIPPING=0
Research and rebuild spec kept for when this is revisited:
reference/ramps/BUILD_SPEC.md, INDEX.md (10 CC-licensed Commons
photos), docs/daikoku-reference-spec.md (OSM circle fits).
65 lines
3.2 KiB
Markdown
65 lines
3.2 KiB
Markdown
# PA Ramp Build Spec — reconciled
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Written 2026-08-03 after research + measurement. Supersedes ad-hoc azimuth
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tuning in `MapBuilder.luau`.
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## Source conflict — READ THIS FIRST
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Two sources disagree, and the disagreement matters:
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| | Generic standard (AASHTO/FHWA/JP, via research) | Measured Daikoku (OSM circle fits) |
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|---|---|---|
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| Ramp form | short shallow **parallel slip road** | **loop helix**, 150–220° of turn |
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| Radius | 80–120 m (285–430 studs) | 71–204 m, mean 131 m (**469 studs**) |
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| Arc | 30–45° | 217° (main helix, rms 1.2 = truly circular) |
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**Resolution: measured Daikoku wins for THIS build.** The generic spec describes
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a typical roadside PA on a flat ground-level expressway. Daikoku PA is not that
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— it sits at the bottom of a **five-level junction stack** on reclaimed land, so
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its ramps are genuinely helical loops, not slip roads. The satellite plan view
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(`aerial/daikoku_z19.jpg`) shows one large-radius arc sweeping around the lot.
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The generic spec is still authoritative for the **merge detail** (below), which
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is not Daikoku-specific.
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## Numbers to build to
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| Quantity | Value | Source |
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|---|---|---|
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| Scale | 3.571 studs/m (1 stud = 0.28 m) | project |
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| Main entry helix radius | **525 studs** (147 m) | OSM way 32403901, rms 1.2 |
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| Secondary helix radius | **440 studs** (124 m) | OSM way 779045459, rms 0.7 |
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| Tight connector radius | 255 studs (71 m) | OSM way 32355896 |
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| Turn direction | **clockwise (right) — BOTH ramps** | 6 of 8 OSM ways; video 「右、右」 |
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| Divergence at merge | 2–5° (current build: 0.1–0.2°, tangent) | AASHTO/FHWA |
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| Deceleration lane | 150–200 m before gore | AASHTO |
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| Acceleration lane | 200–300 m after gore | AASHTO |
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| Gore apex angle | < 5°, chevron-painted over 30–50 m | AASHTO |
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| Superelevation | 4–8% bank on curves | AASHTO |
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| Deck-to-deck spacing | 36–43 studs/level (10–12 m) | JP standard |
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## Hard constraints (checkable in a probe)
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1. **Entry and exit ramps must NEVER intersect.** Current build fails this:
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2547 point-pairs within 30 studs planar at < 12 studs dY, worst case
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**0.5 studs apart at dY = 0.0**. This is the dominant visual defect —
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it reads as a bowtie tangle. Probe must assert 0 such pairs.
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2. Both ramps curve **the same direction** (clockwise). They are at opposite
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ends of the lot and wrap the same way; they do not mirror into each other.
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3. Ramp arc wraps **outside** the parking apron, forming its boundary — it does
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not cut across the lot interior.
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4. Merge is tangent (already achieved: 0.1–0.2°).
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5. No ramp part intersects any Workspace-level building model (obstacle scope
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must be INVERTED, not a name whitelist — see verification skill).
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## Edge / structure treatment (from onboard video + Commons photos)
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- Edge = **low concrete jersey base + see-through chain-link mesh fence above**.
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NOT a tall solid parapet. Current build's heavy kerb chain is why the ramps
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read as thick white rails.
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- **Red/orange chevron shoulder paint** through every ramp curve — present in
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all five reference videos, day and night. Cheapest high-value detail.
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- Piers: **large cylindrical columns**, widely spaced, under a **trapezoidal
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box-girder** deck underside. White/pale concrete.
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- White zebra hatching fills the gore wedge.
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