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).
3.2 KiB
3.2 KiB
PA Ramp Build Spec — reconciled
Written 2026-08-03 after research + measurement. Supersedes ad-hoc azimuth
tuning in MapBuilder.luau.
Source conflict — READ THIS FIRST
Two sources disagree, and the disagreement matters:
| Generic standard (AASHTO/FHWA/JP, via research) | Measured Daikoku (OSM circle fits) | |
|---|---|---|
| Ramp form | short shallow parallel slip road | loop helix, 150–220° of turn |
| Radius | 80–120 m (285–430 studs) | 71–204 m, mean 131 m (469 studs) |
| Arc | 30–45° | 217° (main helix, rms 1.2 = truly circular) |
Resolution: measured Daikoku wins for THIS build. The generic spec describes
a typical roadside PA on a flat ground-level expressway. Daikoku PA is not that
— it sits at the bottom of a five-level junction stack on reclaimed land, so
its ramps are genuinely helical loops, not slip roads. The satellite plan view
(aerial/daikoku_z19.jpg) shows one large-radius arc sweeping around the lot.
The generic spec is still authoritative for the merge detail (below), which is not Daikoku-specific.
Numbers to build to
| Quantity | Value | Source |
|---|---|---|
| Scale | 3.571 studs/m (1 stud = 0.28 m) | project |
| Main entry helix radius | 525 studs (147 m) | OSM way 32403901, rms 1.2 |
| Secondary helix radius | 440 studs (124 m) | OSM way 779045459, rms 0.7 |
| Tight connector radius | 255 studs (71 m) | OSM way 32355896 |
| Turn direction | clockwise (right) — BOTH ramps | 6 of 8 OSM ways; video 「右、右」 |
| Divergence at merge | 2–5° (current build: 0.1–0.2°, tangent) | AASHTO/FHWA |
| Deceleration lane | 150–200 m before gore | AASHTO |
| Acceleration lane | 200–300 m after gore | AASHTO |
| Gore apex angle | < 5°, chevron-painted over 30–50 m | AASHTO |
| Superelevation | 4–8% bank on curves | AASHTO |
| Deck-to-deck spacing | 36–43 studs/level (10–12 m) | JP standard |
Hard constraints (checkable in a probe)
- Entry and exit ramps must NEVER intersect. Current build fails this: 2547 point-pairs within 30 studs planar at < 12 studs dY, worst case 0.5 studs apart at dY = 0.0. This is the dominant visual defect — it reads as a bowtie tangle. Probe must assert 0 such pairs.
- Both ramps curve the same direction (clockwise). They are at opposite ends of the lot and wrap the same way; they do not mirror into each other.
- Ramp arc wraps outside the parking apron, forming its boundary — it does not cut across the lot interior.
- Merge is tangent (already achieved: 0.1–0.2°).
- No ramp part intersects any Workspace-level building model (obstacle scope must be INVERTED, not a name whitelist — see verification skill).
Edge / structure treatment (from onboard video + Commons photos)
- Edge = low concrete jersey base + see-through chain-link mesh fence above. NOT a tall solid parapet. Current build's heavy kerb chain is why the ramps read as thick white rails.
- Red/orange chevron shoulder paint through every ramp curve — present in all five reference videos, day and night. Cheapest high-value detail.
- Piers: large cylindrical columns, widely spaced, under a trapezoidal box-girder deck underside. White/pale concrete.
- White zebra hatching fills the gore wedge.