Research GPS lane connection weighting

docs/traffic-system-debrief.md

@@ -251,11 +251,29 @@ base\worlds\03_night_city\sectors\_generated\traffic\all.traffic_persistent
 
 ## Risks And Unknowns
 
-The main unknown is the native GPS cost formula. If it ignores `maxSpeed`, this
-patch will not meaningfully change routes. If it uses speed but with caps or
-category penalties, the effect may be subtle. If it uses `maxSpeed` for both GPS
-and traffic simulation, the patch may also affect some traffic behavior on
-highways.
+The first major finding from in-game testing is that `maxSpeed` is not a useful
+GPS weighting lever. Raising highway lanes as high as `120` did not change GPS
+routes in the test case, but it did make freeway traffic noticeably faster. That
+means `maxSpeed` should be treated as traffic simulation data, not GPS route
+cost data.
+
+The actual lane adjacency is not populated in `all.traffic_persistent`; every
+lane's `outLanes` array serialized empty. The adjacency is in:
+
+```text
+base\worlds\03_night_city\sectors\_generated\traffic\all.lane_connections
+```
+
+That resource is a `worldTrafficPersistentLaneConnectionsResource` with one row
+per lane. Each row has `inLanes` and `outlanes`. Each outgoing connection
+contains `laneIndex`, `exitProbabilityCompressed`, `isSharpAngle`,
+`nextLaneEntryPosition`, and `thisLaneExitPosition`.
+
+There is still no explicit edge cost field. The current best data-only test is
+to patch `exitProbabilityCompressed`: strongly favor road/GPSOnly/highway
+connections that enter or remain on highways, and lower competing non-highway
+exits. A prepared experimental archive changes 145 outgoing connection
+probabilities across 136 lanes.
 
 The Oodle library was not available inside the toolbox, so WolvenKit packed with
 its Kraken fallback. A vanilla full-resource control archive loaded in game and
@@ -271,10 +289,10 @@ instead.
 Better versions of this mod could:
 
 - build district-specific presets
-- increase highway speed to `22`, `25`, or `30` based on playtesting
-- lower intersection penalties only where highway ramps are misclassified
-- inspect `lane_connections` to identify ramp/arterial topology
-- patch `GPSOnly` connector lanes separately
+- patch `all.lane_connections` probabilities around ramps and highway exits
+- inspect `GPSOnly` connector lanes separately
+- compare route output with probability-only archives enabled
+- locate any native or baked edge-cost data not exposed in RTTI
 - generate a diff report of every changed lane with flags, length, speed, and
   graph component
 - ship multiple archives: conservative, strong, and experimental