{"abstract":"A curbside waypoint accepts arrival from the wrong carriageway in the controlled route-policy fixture.","category":"Navigation route constraints","checks":7,"contract":"This straight east-west two-carriageway model has north/south curbs. A right-driving eastbound vehicle serves south; westbound serves north. Left-driving reverses this. either permits either curb.","contract_signature":"direction, driving_side, curb, road_id, waypoint_road_id","evaluation_group":"model-a66c3ef5176159d2","failed_approach":"Hard-coding right-hand driving reverses curbside access in left-driving regions.","family":"z-navigation_routes-waypoint-curb-side","id":"FA-12236","implementations":{"attempt":{"sha256":"18e77e257c0857a2b003300ad76f8529fcc6748b5a3c9c4a3702344d9e3d69b6","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(direction, driving_side, curb, road_id, waypoint_road_id):\n    return road_id == waypoint_road_id and (curb == 'either' or curb == ('south' if direction == 'east' else 'north'))\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n# Vary approach order without changing the explicitly named physical-side oracle.\nd = 'east' if N % 2 else 'west'\nside = 'south' if N % 2 else 'north'\nother = 'north' if N % 2 else 'south'\ncheck('right-driving served curb', solve(d,'right',side,N,N), True)\ncheck('right-driving opposite curb', solve(d,'right',other,N,N), False)\ncheck('left-driving served curb', solve(d,'left',other,N,N), True)\ncheck('left-driving opposite curb', solve(d,'left',side,N,N), False)\ncheck('unrestricted curb', solve(d,'left','either',N,N), True)\ncheck('different road', solve(d,'right',side,N,N+1), False)\ncheck('different road unrestricted', solve(d,'left','either',N,N+1), False)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"},"broken":{"sha256":"8cf1479715c050ecbb7864511da18d1310929d792cb86cb9af3b00f2fab39e77","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(direction, driving_side, curb, road_id, waypoint_road_id):\n    return road_id == waypoint_road_id\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n# Vary approach order without changing the explicitly named physical-side oracle.\nd = 'east' if N % 2 else 'west'\nside = 'south' if N % 2 else 'north'\nother = 'north' if N % 2 else 'south'\ncheck('right-driving served curb', solve(d,'right',side,N,N), True)\ncheck('right-driving opposite curb', solve(d,'right',other,N,N), False)\ncheck('left-driving served curb', solve(d,'left',other,N,N), True)\ncheck('left-driving opposite curb', solve(d,'left',side,N,N), False)\ncheck('unrestricted curb', solve(d,'left','either',N,N), True)\ncheck('different road', solve(d,'right',side,N,N+1), False)\ncheck('different road unrestricted', solve(d,'left','either',N,N+1), False)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"}},"limitations":"Simplified deterministic offline policy model; not a production router or authoritative road guidance. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.","method":"Deterministic executable model with adversarial boundary fixtures.","provenance":{"created_by":"Failure Map","dependencies":"Python standard library","family":"z-navigation_routes-waypoint-curb-side","generated_at":"2026-09-29T14:38:54.964597+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Navigation policies depend on road context that a shortest-path cost alone does not encode.","root_cause":"Waypoint reachability is based only on road membership, ignoring its required arrival side.","sha256":"ed6212b4a11093ff5d8c28f80d41c3403812e75a69ef1a26e38ca04959da6e08","title":"A curbside waypoint accepts arrival from the wrong carriageway · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":41.291,"exit_code":1,"observations":[{"actual":true,"check":"right-driving served curb","expected":true,"passed":true},{"actual":false,"check":"right-driving opposite curb","expected":false,"passed":true},{"actual":false,"check":"left-driving served curb","expected":true,"passed":false},{"actual":true,"check":"left-driving opposite curb","expected":false,"passed":false},{"actual":true,"check":"unrestricted curb","expected":true,"passed":true},{"actual":false,"check":"different road","expected":false,"passed":true},{"actual":false,"check":"different road unrestricted","expected":false,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"right-driving served curb\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"right-driving opposite curb\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"left-driving served curb\", \"actual\": false, \"expected\": true, \"passed\": false}, {\"check\": \"left-driving opposite curb\", \"actual\": true, \"expected\": false, \"passed\": false}, {\"check\": \"unrestricted curb\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"different road\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"different road unrestricted\", \"actual\": false, \"expected\": false, \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":38.831,"exit_code":1,"observations":[{"actual":true,"check":"right-driving served curb","expected":true,"passed":true},{"actual":true,"check":"right-driving opposite curb","expected":false,"passed":false},{"actual":true,"check":"left-driving served curb","expected":true,"passed":true},{"actual":true,"check":"left-driving opposite curb","expected":false,"passed":false},{"actual":true,"check":"unrestricted curb","expected":true,"passed":true},{"actual":false,"check":"different road","expected":false,"passed":true},{"actual":false,"check":"different road unrestricted","expected":false,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"right-driving served curb\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"right-driving opposite curb\", \"actual\": true, \"expected\": false, \"passed\": false}, {\"check\": \"left-driving served curb\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"left-driving opposite curb\", \"actual\": true, \"expected\": false, \"passed\": false}, {\"check\": \"unrestricted curb\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"different road\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"different road unrestricted\", \"actual\": false, \"expected\": false, \"passed\": true}], \"passed\": false}\n"}},"member_only":{"stages":["fixed"],"fields":["implementations.fixed","verification.fixed","harness","repair"],"note":"The verified repair, its recorded checks, the repair description, and the scoring harness are available to members."}}