{"abstract":"A call-on is given to a train still rolling towards the signal.","category":"Railway interlocking logic","checks":8,"contract":"Without a route the answer is none. With the section ahead clear the main aspect is given. Into an occupied section a call-on is given only if the train has stood at the signal for at least 120 s and is stationary (0 km/h), the gap to the standing train is at least 20 m and that train is not moving; otherwise none.","contract_signature":"x","evaluation_group":"w2-railway_interlocking_logic-call-on-permissive","failed_approach":"Tolerating speeds under 5 km/h still authorises a creeping train.","family":"w2-railway_interlocking_logic-call-on-permissive-stationary-requirement","id":"FA-67206","implementations":{"attempt":{"sha256":"35bfb642d0f21b0094ee4c3f48785f197c0e32903a81a0c158d182aaf35e5fff","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(x):\n    if not x['route_set']:\n        return 'none'\n    if not x['ahead_occupied']:\n        return 'main'\n    if x['stand_s'] < 120 or x['speed_kmh'] >= 5:\n        return 'none'\n    if x['gap_m'] < 20:\n        return 'none'\n    if x['platform_train_moving']:\n        return 'none'\n    return 'call-on'\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[('regression: creeping at walking pace', {'route_set': True, 'ahead_occupied': True, 'stand_s': 200, 'speed_kmh': 3, 'gap_m': 100, 'platform_train_moving': False}, 'none'), ('sampled regression 25', {'route_set': True, 'ahead_occupied': True, 'stand_s': 120, 'speed_kmh': 15, 'gap_m': 21, 'platform_train_moving': False}, 'none'), ('boundary: stood exactly two minutes', {'route_set': True, 'ahead_occupied': True, 'stand_s': 120, 'speed_kmh': 0, 'gap_m': 100, 'platform_train_moving': False}, 'call-on'), ('boundary: stood one second short', {'route_set': True, 'ahead_occupied': True, 'stand_s': 119, 'speed_kmh': 0, 'gap_m': 100, 'platform_train_moving': False}, 'none'), ('regression: rolling at call-on speed', {'route_set': True, 'ahead_occupied': True, 'stand_s': 200, 'speed_kmh': 12, 'gap_m': 100, 'platform_train_moving': False}, 'none'), ('control 1', {'route_set': True, 'ahead_occupied': False, 'stand_s': 300, 'speed_kmh': 0, 'gap_m': 60, 'platform_train_moving': False}, 'main'), ('control 4', {'route_set': True, 'ahead_occupied': True, 'stand_s': 120, 'speed_kmh': 3, 'gap_m': 200, 'platform_train_moving': True}, 'none'), ('control 7', {'route_set': True, 'ahead_occupied': True, 'stand_s': 120, 'speed_kmh': 3, 'gap_m': 19, 'platform_train_moving': False}, 'none')], [('regression: rolling at call-on speed', {'route_set': True, 'ahead_occupied': True, 'stand_s': 200, 'speed_kmh': 12, 'gap_m': 100, 'platform_train_moving': False}, 'none'), ('regression: creeping at walking pace', {'route_set': True, 'ahead_occupied': True, 'stand_s': 200, 'speed_kmh': 3, 'gap_m': 100, 'platform_train_moving': False}, 'none'), ('boundary: platform train moving far away', {'route_set': True, 'ahead_occupied': True, 'stand_s': 200, 'speed_kmh': 0, 'gap_m': 200, 'platform_train_moving': True}, 'none'), ('boundary: platform train moving close by', {'route_set': True, 'ahead_occupied': True, 'stand_s': 200, 'speed_kmh': 0, 'gap_m': 30, 'platform_train_moving': True}, 'none'), ('boundary: gap exactly at the minimum', {'route_set': True, 'ahead_occupied': True, 'stand_s': 200, 'speed_kmh': 0, 'gap_m': 20, 'platform_train_moving': False}, 'call-on'), ('control 12', {'route_set': True, 'ahead_occupied': True, 'stand_s': 300, 'speed_kmh': 0, 'gap_m': 5, 'platform_train_moving': False}, 'none'), ('control 15', {'route_set': True, 'ahead_occupied': True, 'stand_s': 119, 'speed_kmh': 20, 'gap_m': 19, 'platform_train_moving': True}, 'none'), ('control 18', {'route_set': True, 'ahead_occupied': True, 'stand_s': 0, 'speed_kmh': 0, 'gap_m': 20, 'platform_train_moving': True}, 'none')], [('regression: creeping at walking pace', {'route_set': True, 'ahead_occupied': True, 'stand_s': 200, 'speed_kmh': 3, 'gap_m': 100, 'platform_train_moving': False}, 'none'), ('sampled regression 5', {'route_set': True, 'ahead_occupied': True, 'stand_s': 121, 'speed_kmh': 10, 'gap_m': 200, 'platform_train_moving': False}, 'none'), ('boundary: platform train moving far away', {'route_set': True, 'ahead_occupied': True, 'stand_s': 200, 'speed_kmh': 0, 'gap_m': 200, 'platform_train_moving': True}, 'none'), ('boundary: platform train moving close by', {'route_set': True, 'ahead_occupied': True, 'stand_s': 200, 'speed_kmh': 0, 'gap_m': 30, 'platform_train_moving': True}, 'none'), ('boundary: gap exactly at the minimum', {'route_set': True, 'ahead_occupied': True, 'stand_s': 200, 'speed_kmh': 0, 'gap_m': 20, 'platform_train_moving': False}, 'call-on'), ('control 23', {'route_set': True, 'ahead_occupied': True, 'stand_s': 30, 'speed_kmh': 15, 'gap_m': 200, 'platform_train_moving': False}, 'none'), ('control 26', {'route_set': False, 'ahead_occupied': True, 'stand_s': 120, 'speed_kmh': 0, 'gap_m': 19, 'platform_train_moving': False}, 'none'), ('control 29', {'route_set': True, 'ahead_occupied': True, 'stand_s': 30, 'speed_kmh': 20, 'gap_m': 19, 'platform_train_moving': False}, 'none')], [('regression: rolling at call-on speed', {'route_set': True, 'ahead_occupied': True, 'stand_s': 200, 'speed_kmh': 12, 'gap_m': 100, 'platform_train_moving': False}, 'none'), ('regression: creeping at walking pace', {'route_set': True, 'ahead_occupied': True, 'stand_s': 200, 'speed_kmh': 3, 'gap_m': 100, 'platform_train_moving': False}, 'none'), ('sampled regression 76', {'route_set': True, 'ahead_occupied': True, 'stand_s': 300, 'speed_kmh': 10, 'gap_m': 20, 'platform_train_moving': False}, 'none'), ('boundary: gap exactly at the minimum', {'route_set': True, 'ahead_occupied': True, 'stand_s': 200, 'speed_kmh': 0, 'gap_m': 20, 'platform_train_moving': False}, 'call-on'), ('boundary: clear platform for a moving train', {'route_set': True, 'ahead_occupied': False, 'stand_s': 0, 'speed_kmh': 40, 'gap_m': 100, 'platform_train_moving': False}, 'main'), ('control 34', {'route_set': True, 'ahead_occupied': True, 'stand_s': 120, 'speed_kmh': 20, 'gap_m': 60, 'platform_train_moving': False}, 'none'), ('control 37', {'route_set': True, 'ahead_occupied': True, 'stand_s': 0, 'speed_kmh': 20, 'gap_m': 19, 'platform_train_moving': False}, 'none'), ('control 40', {'route_set': True, 'ahead_occupied': True, 'stand_s': 121, 'speed_kmh': 0, 'gap_m': 200, 'platform_train_moving': False}, 'call-on')], [('regression: creeping at walking pace', {'route_set': True, 'ahead_occupied': True, 'stand_s': 200, 'speed_kmh': 3, 'gap_m': 100, 'platform_train_moving': False}, 'none'), ('regression: rolling at call-on speed', {'route_set': True, 'ahead_occupied': True, 'stand_s': 200, 'speed_kmh': 12, 'gap_m': 100, 'platform_train_moving': False}, 'none'), ('boundary: no route', {'route_set': False, 'ahead_occupied': False, 'stand_s': 200, 'speed_kmh': 0, 'gap_m': 100, 'platform_train_moving': False}, 'none'), ('boundary: stood exactly two minutes', {'route_set': True, 'ahead_occupied': True, 'stand_s': 120, 'speed_kmh': 0, 'gap_m': 100, 'platform_train_moving': False}, 'call-on'), ('boundary: stood one second short', {'route_set': True, 'ahead_occupied': True, 'stand_s': 119, 'speed_kmh': 0, 'gap_m': 100, 'platform_train_moving': False}, 'none'), ('control 45', {'route_set': True, 'ahead_occupied': True, 'stand_s': 120, 'speed_kmh': 0, 'gap_m': 5, 'platform_train_moving': False}, 'none'), ('control 48', {'route_set': True, 'ahead_occupied': True, 'stand_s': 30, 'speed_kmh': 20, 'gap_m': 200, 'platform_train_moving': False}, 'none'), ('control 51', {'route_set': True, 'ahead_occupied': False, 'stand_s': 300, 'speed_kmh': 3, 'gap_m': 20, 'platform_train_moving': False}, 'main')]]\nfor label, args, expected in fixtures[N-1]:\n    check(label, solve(args), expected)\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":"3f662fd1ea3297115f3c22e6da6f25b8c850325254be7cb4490bd0c50c2062dc","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(x):\n    if not x['route_set']:\n        return 'none'\n    if not x['ahead_occupied']:\n        return 'main'\n    if x['stand_s'] < 120 or x['speed_kmh'] > 15:\n        return 'none'\n    if x['gap_m'] < 20:\n        return 'none'\n    if x['platform_train_moving']:\n        return 'none'\n    return 'call-on'\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[('regression: creeping at walking pace', {'route_set': True, 'ahead_occupied': True, 'stand_s': 200, 'speed_kmh': 3, 'gap_m': 100, 'platform_train_moving': False}, 'none'), ('sampled regression 25', {'route_set': True, 'ahead_occupied': True, 'stand_s': 120, 'speed_kmh': 15, 'gap_m': 21, 'platform_train_moving': False}, 'none'), ('boundary: stood exactly two minutes', {'route_set': True, 'ahead_occupied': True, 'stand_s': 120, 'speed_kmh': 0, 'gap_m': 100, 'platform_train_moving': False}, 'call-on'), ('boundary: stood one second short', {'route_set': True, 'ahead_occupied': True, 'stand_s': 119, 'speed_kmh': 0, 'gap_m': 100, 'platform_train_moving': False}, 'none'), ('regression: rolling at call-on speed', {'route_set': True, 'ahead_occupied': True, 'stand_s': 200, 'speed_kmh': 12, 'gap_m': 100, 'platform_train_moving': False}, 'none'), ('control 1', {'route_set': True, 'ahead_occupied': False, 'stand_s': 300, 'speed_kmh': 0, 'gap_m': 60, 'platform_train_moving': False}, 'main'), ('control 4', {'route_set': True, 'ahead_occupied': True, 'stand_s': 120, 'speed_kmh': 3, 'gap_m': 200, 'platform_train_moving': True}, 'none'), ('control 7', {'route_set': True, 'ahead_occupied': True, 'stand_s': 120, 'speed_kmh': 3, 'gap_m': 19, 'platform_train_moving': False}, 'none')], [('regression: rolling at call-on speed', {'route_set': True, 'ahead_occupied': True, 'stand_s': 200, 'speed_kmh': 12, 'gap_m': 100, 'platform_train_moving': False}, 'none'), ('regression: creeping at walking pace', {'route_set': True, 'ahead_occupied': True, 'stand_s': 200, 'speed_kmh': 3, 'gap_m': 100, 'platform_train_moving': False}, 'none'), ('boundary: platform train moving far away', {'route_set': True, 'ahead_occupied': True, 'stand_s': 200, 'speed_kmh': 0, 'gap_m': 200, 'platform_train_moving': True}, 'none'), ('boundary: platform train moving close by', {'route_set': True, 'ahead_occupied': True, 'stand_s': 200, 'speed_kmh': 0, 'gap_m': 30, 'platform_train_moving': True}, 'none'), ('boundary: gap exactly at the minimum', {'route_set': True, 'ahead_occupied': True, 'stand_s': 200, 'speed_kmh': 0, 'gap_m': 20, 'platform_train_moving': False}, 'call-on'), ('control 12', {'route_set': True, 'ahead_occupied': True, 'stand_s': 300, 'speed_kmh': 0, 'gap_m': 5, 'platform_train_moving': False}, 'none'), ('control 15', {'route_set': True, 'ahead_occupied': True, 'stand_s': 119, 'speed_kmh': 20, 'gap_m': 19, 'platform_train_moving': True}, 'none'), ('control 18', {'route_set': True, 'ahead_occupied': True, 'stand_s': 0, 'speed_kmh': 0, 'gap_m': 20, 'platform_train_moving': True}, 'none')], [('regression: creeping at walking pace', {'route_set': True, 'ahead_occupied': True, 'stand_s': 200, 'speed_kmh': 3, 'gap_m': 100, 'platform_train_moving': False}, 'none'), ('sampled regression 5', {'route_set': True, 'ahead_occupied': True, 'stand_s': 121, 'speed_kmh': 10, 'gap_m': 200, 'platform_train_moving': False}, 'none'), ('boundary: platform train moving far away', {'route_set': True, 'ahead_occupied': True, 'stand_s': 200, 'speed_kmh': 0, 'gap_m': 200, 'platform_train_moving': True}, 'none'), ('boundary: platform train moving close by', {'route_set': True, 'ahead_occupied': True, 'stand_s': 200, 'speed_kmh': 0, 'gap_m': 30, 'platform_train_moving': True}, 'none'), ('boundary: gap exactly at the minimum', {'route_set': True, 'ahead_occupied': True, 'stand_s': 200, 'speed_kmh': 0, 'gap_m': 20, 'platform_train_moving': False}, 'call-on'), ('control 23', {'route_set': True, 'ahead_occupied': True, 'stand_s': 30, 'speed_kmh': 15, 'gap_m': 200, 'platform_train_moving': False}, 'none'), ('control 26', {'route_set': False, 'ahead_occupied': True, 'stand_s': 120, 'speed_kmh': 0, 'gap_m': 19, 'platform_train_moving': False}, 'none'), ('control 29', {'route_set': True, 'ahead_occupied': True, 'stand_s': 30, 'speed_kmh': 20, 'gap_m': 19, 'platform_train_moving': False}, 'none')], [('regression: rolling at call-on speed', {'route_set': True, 'ahead_occupied': True, 'stand_s': 200, 'speed_kmh': 12, 'gap_m': 100, 'platform_train_moving': False}, 'none'), ('regression: creeping at walking pace', {'route_set': True, 'ahead_occupied': True, 'stand_s': 200, 'speed_kmh': 3, 'gap_m': 100, 'platform_train_moving': False}, 'none'), ('sampled regression 76', {'route_set': True, 'ahead_occupied': True, 'stand_s': 300, 'speed_kmh': 10, 'gap_m': 20, 'platform_train_moving': False}, 'none'), ('boundary: gap exactly at the minimum', {'route_set': True, 'ahead_occupied': True, 'stand_s': 200, 'speed_kmh': 0, 'gap_m': 20, 'platform_train_moving': False}, 'call-on'), ('boundary: clear platform for a moving train', {'route_set': True, 'ahead_occupied': False, 'stand_s': 0, 'speed_kmh': 40, 'gap_m': 100, 'platform_train_moving': False}, 'main'), ('control 34', {'route_set': True, 'ahead_occupied': True, 'stand_s': 120, 'speed_kmh': 20, 'gap_m': 60, 'platform_train_moving': False}, 'none'), ('control 37', {'route_set': True, 'ahead_occupied': True, 'stand_s': 0, 'speed_kmh': 20, 'gap_m': 19, 'platform_train_moving': False}, 'none'), ('control 40', {'route_set': True, 'ahead_occupied': True, 'stand_s': 121, 'speed_kmh': 0, 'gap_m': 200, 'platform_train_moving': False}, 'call-on')], [('regression: creeping at walking pace', {'route_set': True, 'ahead_occupied': True, 'stand_s': 200, 'speed_kmh': 3, 'gap_m': 100, 'platform_train_moving': False}, 'none'), ('regression: rolling at call-on speed', {'route_set': True, 'ahead_occupied': True, 'stand_s': 200, 'speed_kmh': 12, 'gap_m': 100, 'platform_train_moving': False}, 'none'), ('boundary: no route', {'route_set': False, 'ahead_occupied': False, 'stand_s': 200, 'speed_kmh': 0, 'gap_m': 100, 'platform_train_moving': False}, 'none'), ('boundary: stood exactly two minutes', {'route_set': True, 'ahead_occupied': True, 'stand_s': 120, 'speed_kmh': 0, 'gap_m': 100, 'platform_train_moving': False}, 'call-on'), ('boundary: stood one second short', {'route_set': True, 'ahead_occupied': True, 'stand_s': 119, 'speed_kmh': 0, 'gap_m': 100, 'platform_train_moving': False}, 'none'), ('control 45', {'route_set': True, 'ahead_occupied': True, 'stand_s': 120, 'speed_kmh': 0, 'gap_m': 5, 'platform_train_moving': False}, 'none'), ('control 48', {'route_set': True, 'ahead_occupied': True, 'stand_s': 30, 'speed_kmh': 20, 'gap_m': 200, 'platform_train_moving': False}, 'none'), ('control 51', {'route_set': True, 'ahead_occupied': False, 'stand_s': 300, 'speed_kmh': 3, 'gap_m': 20, 'platform_train_moving': False}, 'main')]]\nfor label, args, expected in fixtures[N-1]:\n    check(label, solve(args), expected)\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":"Stipulated toy interlocking contract for a bounded teaching model; it makes no claim of conformance to any railway signalling standard and omits real safety cases. 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":"w2-railway_interlocking_logic-call-on-permissive-stationary-requirement","generated_at":"2026-09-29T14:47:50.664742+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Interlocking logic decides whether trains may be given authority; a wrong decision at this point either grants unsafe movements or strands traffic.","root_cause":"The call-on speed limit is used where standstill is required.","sha256":"28aed8615ae014d43d50fadf0443607f65a5a4486ca375e8cded15cd7101c7e8","title":"Call-on permissive move authorisation: stationary requirement · 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":36.71,"exit_code":1,"observations":[{"actual":"call-on","check":"regression: creeping at walking pace","expected":"none","passed":false},{"actual":"none","check":"sampled regression 25","expected":"none","passed":true},{"actual":"call-on","check":"boundary: stood exactly two minutes","expected":"call-on","passed":true},{"actual":"none","check":"boundary: stood one second short","expected":"none","passed":true},{"actual":"none","check":"regression: rolling at call-on speed","expected":"none","passed":true},{"actual":"main","check":"control 1","expected":"main","passed":true},{"actual":"none","check":"control 4","expected":"none","passed":true},{"actual":"none","check":"control 7","expected":"none","passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"regression: creeping at walking pace\", \"actual\": \"call-on\", \"expected\": \"none\", \"passed\": false}, {\"check\": \"sampled regression 25\", \"actual\": \"none\", \"expected\": \"none\", \"passed\": true}, {\"check\": \"boundary: stood exactly two minutes\", \"actual\": \"call-on\", \"expected\": \"call-on\", \"passed\": true}, {\"check\": \"boundary: stood one second short\", \"actual\": \"none\", \"expected\": \"none\", \"passed\": true}, {\"check\": \"regression: rolling at call-on speed\", \"actual\": \"none\", \"expected\": \"none\", \"passed\": true}, {\"check\": \"control 1\", \"actual\": \"main\", \"expected\": \"main\", \"passed\": true}, {\"check\": \"control 4\", \"actual\": \"none\", \"expected\": \"none\", \"passed\": true}, {\"check\": \"control 7\", \"actual\": \"none\", \"expected\": \"none\", \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":39.526,"exit_code":1,"observations":[{"actual":"call-on","check":"regression: creeping at walking pace","expected":"none","passed":false},{"actual":"call-on","check":"sampled regression 25","expected":"none","passed":false},{"actual":"call-on","check":"boundary: stood exactly two minutes","expected":"call-on","passed":true},{"actual":"none","check":"boundary: stood one second short","expected":"none","passed":true},{"actual":"call-on","check":"regression: rolling at call-on speed","expected":"none","passed":false},{"actual":"main","check":"control 1","expected":"main","passed":true},{"actual":"none","check":"control 4","expected":"none","passed":true},{"actual":"none","check":"control 7","expected":"none","passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"regression: creeping at walking pace\", \"actual\": \"call-on\", \"expected\": \"none\", \"passed\": false}, {\"check\": \"sampled regression 25\", \"actual\": \"call-on\", \"expected\": \"none\", \"passed\": false}, {\"check\": \"boundary: stood exactly two minutes\", \"actual\": \"call-on\", \"expected\": \"call-on\", \"passed\": true}, {\"check\": \"boundary: stood one second short\", \"actual\": \"none\", \"expected\": \"none\", \"passed\": true}, {\"check\": \"regression: rolling at call-on speed\", \"actual\": \"call-on\", \"expected\": \"none\", \"passed\": false}, {\"check\": \"control 1\", \"actual\": \"main\", \"expected\": \"main\", \"passed\": true}, {\"check\": \"control 4\", \"actual\": \"none\", \"expected\": \"none\", \"passed\": true}, {\"check\": \"control 7\", \"actual\": \"none\", \"expected\": \"none\", \"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."}}