Enable SD-HD conflation support for traffic symbols.

GitOrigin-RevId: 5c8339890d4c29670907ca4e9e8f2bbe7036b852

Author: astojilj

3d-style/data/frc_road_classes.ts

@@ -13,10 +13,13 @@ const roadTypeToFrcMap: Record<string, number> = {
 };
 
 export function featureFrcLevel(featureProperties: Record<string, unknown>): number | null {
-    const cls = featureProperties['class'];
-    if (typeof cls !== 'string') return null;
-    const frc = roadTypeToFrcMap[cls];
-    return frc !== undefined ? frc : null;
+    for (const key of ['class', 'incident_class']) {
+        const cls = featureProperties[key];
+        if (typeof cls !== 'string') continue;
+        const frc = roadTypeToFrcMap[cls];
+        if (frc !== undefined) return frc;
+    }
+    return null;
 }
 
 export function isFeatureCoveredByFrcMask(featureProperties: Record<string, unknown>, frcMask: number): boolean {

test/unit/source/frc_coverage.test.ts

@@ -73,6 +73,19 @@ describe('frc_road_classes', () => {
         test('missing class returns null', () => {
             expect(featureFrcLevel({})).toBeNull();
         });
+
+        test('incident_class used as fallback when class is absent', () => {
+            expect(featureFrcLevel({'incident_class': 'motorway'})).toBe(0);
+            expect(featureFrcLevel({'incident_class': 'primary'})).toBe(2);
+        });
+
+        test('class takes precedence over incident_class', () => {
+            expect(featureFrcLevel({'class': 'motorway', 'incident_class': 'service'})).toBe(0);
+        });
+
+        test('unknown incident_class returns null', () => {
+            expect(featureFrcLevel({'incident_class': 'aeroway'})).toBeNull();
+        });
     });
 
     describe('isFeatureCoveredByFrcMask', () => {
@@ -101,6 +114,11 @@ describe('frc_road_classes', () => {
             expect(isFeatureCoveredByFrcMask({class: 'primary'}, mask)).toBe(true);
             expect(isFeatureCoveredByFrcMask({class: 'secondary'}, mask)).toBe(false);
         });
+
+        test('incident_class fallback works in coverage check', () => {
+            expect(isFeatureCoveredByFrcMask({'incident_class': 'motorway'}, 0b1)).toBe(true);
+            expect(isFeatureCoveredByFrcMask({'incident_class': 'motorway'}, 0b10)).toBe(false);
+        });
     });
 
     describe('matchesCoverageSourceLayer', () => {