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FA-68191 / Traffic signal timing plans / Open access

Railroad preemption entry timing: track phase in yellow is treated as already serving · case 01

Railroad preemption entry timing returns a wrong result when track phase in yellow is treated as already serving.

Verified by executionVariant 1 · 8 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

A track clearance phase that is already in yellow is reported as serving, so it is never re-served.

VERIFIED REPAIR

Restore the track phase already green rule so that the step reads `if st == 'green' and x['track_current']:`.

Unsuccessful approach: Accepting yellow as serving still skips the required re-service of the track phase.

Case contract

Input {state: green|yellow|red (red = all-red clearance), elapsed, min_green, preempt_min_green, yellow, red, fdw, ped: none|walk|fdw, ped_elapsed, ped_truncate, track_current}. If the track clearance phase is already green the answer is [0, 0]. In all-red the remaining red is timed; in yellow the remaining yellow and full red are timed. In green the hold is the larger of the remaining preempt minimum green (not the normal minimum) and the pedestrian time: walk is abandoned and FDW is timed in full, or skipped when ped_truncate; an active FDW completes its remainder unless truncated. Return [seconds until track clearance green, green hold].

Why this case matters

Signal timing arithmetic is exact and integer or rational; a wrong rule silently produces unsafe or inefficient timing plans.

1 / The failure

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(x):
    st, el = x['state'], x['elapsed']
    y, r, f = x['yellow'], x['red'], x['fdw']
    if x['track_current']:
        return [0, 0]
    if st == 'red':
        return [max(0, r - el), 0]
    if st == 'yellow':
        return [max(0, y - el) + r, 0]
    ped = 0
    if x['ped'] == 'walk':
        ped = 0 if x['ped_truncate'] else f
    elif x['ped'] == 'fdw':
        ped = 0 if x['ped_truncate'] else max(0, f - x['ped_elapsed'])
    hold = max(ped, max(0, x['preempt_min_green'] - el))
    return [hold + y + r, hold]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[({'state': 'yellow', 'elapsed': 18, 'min_green': 19, 'preempt_min_green': 6, 'yellow': 5, 'red': 3, 'fdw': 21, 'ped': 'none', 'ped_elapsed': 0, 'ped_truncate': True, 'track_current': True}, [3, 0]), ({'state': 'yellow', 'elapsed': 2, 'min_green': 10, 'preempt_min_green': 4, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'none', 'ped_elapsed': 0, 'ped_truncate': False, 'track_current': True}, [4, 0]), ({'state': 'green', 'elapsed': 18, 'min_green': 15, 'preempt_min_green': 7, 'yellow': 4, 'red': 1, 'fdw': 15, 'ped': 'walk', 'ped_elapsed': 8, 'ped_truncate': True, 'track_current': False}, [5, 0]), ({'state': 'yellow', 'elapsed': 4, 'min_green': 16, 'preempt_min_green': 3, 'yellow': 5, 'red': 3, 'fdw': 14, 'ped': 'none', 'ped_elapsed': 19, 'ped_truncate': False, 'track_current': False}, [4, 0]), ({'state': 'yellow', 'elapsed': 12, 'min_green': 14, 'preempt_min_green': 3, 'yellow': 3, 'red': 2, 'fdw': 23, 'ped': 'none', 'ped_elapsed': 6, 'ped_truncate': True, 'track_current': True}, [2, 0]), ({'state': 'red', 'elapsed': 7, 'min_green': 9, 'preempt_min_green': 10, 'yellow': 3, 'red': 1, 'fdw': 9, 'ped': 'none', 'ped_elapsed': 12, 'ped_truncate': False, 'track_current': False}, [0, 0]), ({'state': 'green', 'elapsed': 1, 'min_green': 15, 'preempt_min_green': 5, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'fdw', 'ped_elapsed': 4, 'ped_truncate': False, 'track_current': False}, [14, 8]), ({'state': 'green', 'elapsed': 20, 'min_green': 18, 'preempt_min_green': 10, 'yellow': 3, 'red': 2, 'fdw': 8, 'ped': 'none', 'ped_elapsed': 7, 'ped_truncate': False, 'track_current': True}, [0, 0])], [({'state': 'green', 'elapsed': 6, 'min_green': 11, 'preempt_min_green': 6, 'yellow': 6, 'red': 3, 'fdw': 11, 'ped': 'none', 'ped_elapsed': 9, 'ped_truncate': False, 'track_current': False}, [9, 0]), ({'state': 'green', 'elapsed': 1, 'min_green': 15, 'preempt_min_green': 5, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'fdw', 'ped_elapsed': 4, 'ped_truncate': False, 'track_current': False}, [14, 8]), ({'state': 'green', 'elapsed': 9, 'min_green': 12, 'preempt_min_green': 3, 'yellow': 4, 'red': 2, 'fdw': 11, 'ped': 'none', 'ped_elapsed': 18, 'ped_truncate': False, 'track_current': False}, [6, 0]), ({'state': 'yellow', 'elapsed': 9, 'min_green': 13, 'preempt_min_green': 8, 'yellow': 5, 'red': 1, 'fdw': 10, 'ped': 'none', 'ped_elapsed': 15, 'ped_truncate': False, 'track_current': True}, [1, 0]), ({'state': 'green', 'elapsed': 10, 'min_green': 10, 'preempt_min_green': 6, 'yellow': 3, 'red': 3, 'fdw': 25, 'ped': 'walk', 'ped_elapsed': 17, 'ped_truncate': False, 'track_current': False}, [31, 25]), ({'state': 'yellow', 'elapsed': 2, 'min_green': 10, 'preempt_min_green': 4, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'none', 'ped_elapsed': 0, 'ped_truncate': False, 'track_current': True}, [4, 0]), ({'state': 'green', 'elapsed': 11, 'min_green': 10, 'preempt_min_green': 4, 'yellow': 5, 'red': 1, 'fdw': 15, 'ped': 'fdw', 'ped_elapsed': 6, 'ped_truncate': True, 'track_current': False}, [6, 0]), ({'state': 'yellow', 'elapsed': 16, 'min_green': 19, 'preempt_min_green': 3, 'yellow': 5, 'red': 2, 'fdw': 13, 'ped': 'none', 'ped_elapsed': 19, 'ped_truncate': True, 'track_current': True}, [2, 0])], [({'state': 'yellow', 'elapsed': 2, 'min_green': 10, 'preempt_min_green': 4, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'none', 'ped_elapsed': 0, 'ped_truncate': False, 'track_current': True}, [4, 0]), ({'state': 'green', 'elapsed': 12, 'min_green': 8, 'preempt_min_green': 7, 'yellow': 5, 'red': 1, 'fdw': 24, 'ped': 'walk', 'ped_elapsed': 4, 'ped_truncate': False, 'track_current': False}, [30, 24]), ({'state': 'red', 'elapsed': 0, 'min_green': 14, 'preempt_min_green': 5, 'yellow': 3, 'red': 1, 'fdw': 15, 'ped': 'none', 'ped_elapsed': 18, 'ped_truncate': False, 'track_current': True}, [1, 0]), ({'state': 'green', 'elapsed': 1, 'min_green': 15, 'preempt_min_green': 5, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'fdw', 'ped_elapsed': 4, 'ped_truncate': False, 'track_current': False}, [14, 8]), ({'state': 'green', 'elapsed': 6, 'min_green': 20, 'preempt_min_green': 9, 'yellow': 4, 'red': 3, 'fdw': 25, 'ped': 'none', 'ped_elapsed': 1, 'ped_truncate': True, 'track_current': False}, [10, 3]), ({'state': 'green', 'elapsed': 10, 'min_green': 18, 'preempt_min_green': 2, 'yellow': 3, 'red': 1, 'fdw': 20, 'ped': 'none', 'ped_elapsed': 20, 'ped_truncate': False, 'track_current': False}, [4, 0]), ({'state': 'red', 'elapsed': 18, 'min_green': 16, 'preempt_min_green': 10, 'yellow': 6, 'red': 2, 'fdw': 25, 'ped': 'none', 'ped_elapsed': 13, 'ped_truncate': False, 'track_current': False}, [0, 0]), ({'state': 'yellow', 'elapsed': 9, 'min_green': 18, 'preempt_min_green': 3, 'yellow': 6, 'red': 3, 'fdw': 15, 'ped': 'none', 'ped_elapsed': 9, 'ped_truncate': False, 'track_current': True}, [3, 0])], [({'state': 'yellow', 'elapsed': 6, 'min_green': 20, 'preempt_min_green': 5, 'yellow': 3, 'red': 3, 'fdw': 19, 'ped': 'none', 'ped_elapsed': 10, 'ped_truncate': True, 'track_current': False}, [3, 0]), ({'state': 'yellow', 'elapsed': 4, 'min_green': 20, 'preempt_min_green': 8, 'yellow': 6, 'red': 1, 'fdw': 14, 'ped': 'none', 'ped_elapsed': 11, 'ped_truncate': True, 'track_current': True}, [3, 0]), ({'state': 'yellow', 'elapsed': 2, 'min_green': 10, 'preempt_min_green': 4, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'none', 'ped_elapsed': 0, 'ped_truncate': False, 'track_current': True}, [4, 0]), ({'state': 'green', 'elapsed': 6, 'min_green': 17, 'preempt_min_green': 4, 'yellow': 4, 'red': 3, 'fdw': 25, 'ped': 'fdw', 'ped_elapsed': 1, 'ped_truncate': False, 'track_current': False}, [31, 24]), ({'state': 'red', 'elapsed': 7, 'min_green': 13, 'preempt_min_green': 2, 'yellow': 6, 'red': 1, 'fdw': 21, 'ped': 'none', 'ped_elapsed': 6, 'ped_truncate': False, 'track_current': False}, [0, 0]), ({'state': 'green', 'elapsed': 1, 'min_green': 15, 'preempt_min_green': 5, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'fdw', 'ped_elapsed': 4, 'ped_truncate': False, 'track_current': False}, [14, 8]), ({'state': 'green', 'elapsed': 2, 'min_green': 20, 'preempt_min_green': 9, 'yellow': 4, 'red': 3, 'fdw': 18, 'ped': 'none', 'ped_elapsed': 6, 'ped_truncate': False, 'track_current': False}, [14, 7]), ({'state': 'yellow', 'elapsed': 12, 'min_green': 12, 'preempt_min_green': 10, 'yellow': 5, 'red': 1, 'fdw': 19, 'ped': 'none', 'ped_elapsed': 9, 'ped_truncate': False, 'track_current': True}, [1, 0])], [({'state': 'red', 'elapsed': 1, 'min_green': 11, 'preempt_min_green': 2, 'yellow': 3, 'red': 3, 'fdw': 22, 'ped': 'none', 'ped_elapsed': 2, 'ped_truncate': True, 'track_current': False}, [2, 0]), ({'state': 'yellow', 'elapsed': 11, 'min_green': 18, 'preempt_min_green': 9, 'yellow': 6, 'red': 3, 'fdw': 25, 'ped': 'none', 'ped_elapsed': 11, 'ped_truncate': False, 'track_current': True}, [3, 0]), ({'state': 'green', 'elapsed': 12, 'min_green': 18, 'preempt_min_green': 10, 'yellow': 6, 'red': 2, 'fdw': 18, 'ped': 'fdw', 'ped_elapsed': 19, 'ped_truncate': False, 'track_current': True}, [0, 0]), ({'state': 'yellow', 'elapsed': 2, 'min_green': 10, 'preempt_min_green': 4, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'none', 'ped_elapsed': 0, 'ped_truncate': False, 'track_current': True}, [4, 0]), ({'state': 'yellow', 'elapsed': 8, 'min_green': 11, 'preempt_min_green': 7, 'yellow': 3, 'red': 3, 'fdw': 22, 'ped': 'none', 'ped_elapsed': 10, 'ped_truncate': True, 'track_current': True}, [3, 0]), ({'state': 'red', 'elapsed': 9, 'min_green': 11, 'preempt_min_green': 10, 'yellow': 5, 'red': 1, 'fdw': 20, 'ped': 'none', 'ped_elapsed': 19, 'ped_truncate': True, 'track_current': False}, [0, 0]), ({'state': 'green', 'elapsed': 1, 'min_green': 15, 'preempt_min_green': 5, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'fdw', 'ped_elapsed': 4, 'ped_truncate': False, 'track_current': False}, [14, 8]), ({'state': 'green', 'elapsed': 13, 'min_green': 14, 'preempt_min_green': 2, 'yellow': 4, 'red': 2, 'fdw': 11, 'ped': 'none', 'ped_elapsed': 19, 'ped_truncate': True, 'track_current': False}, [6, 0])]]
for i, (args, expected) in enumerate(fixtures[N-1]):
    check('timing oracle' + ' %d' % i, solve(args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
timing oracle 0[0, 0][3, 0]Failed
timing oracle 1[0, 0][4, 0]Failed
timing oracle 2[5, 0][5, 0]Passed
timing oracle 3[4, 0][4, 0]Passed
timing oracle 4[0, 0][2, 0]Failed
timing oracle 5[0, 0][0, 0]Passed
timing oracle 6[14, 8][14, 8]Passed
timing oracle 7[0, 0][0, 0]Passed

SHA-256 / 2a1f5d2052b6ac87fc6b12da1dd628cbbda0b7e5e86ba6b29fc473a2a0dc0c17

2 / The unsuccessful fix

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(x):
    st, el = x['state'], x['elapsed']
    y, r, f = x['yellow'], x['red'], x['fdw']
    if st != 'red' and x['track_current']:
        return [0, 0]
    if st == 'red':
        return [max(0, r - el), 0]
    if st == 'yellow':
        return [max(0, y - el) + r, 0]
    ped = 0
    if x['ped'] == 'walk':
        ped = 0 if x['ped_truncate'] else f
    elif x['ped'] == 'fdw':
        ped = 0 if x['ped_truncate'] else max(0, f - x['ped_elapsed'])
    hold = max(ped, max(0, x['preempt_min_green'] - el))
    return [hold + y + r, hold]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[({'state': 'yellow', 'elapsed': 18, 'min_green': 19, 'preempt_min_green': 6, 'yellow': 5, 'red': 3, 'fdw': 21, 'ped': 'none', 'ped_elapsed': 0, 'ped_truncate': True, 'track_current': True}, [3, 0]), ({'state': 'yellow', 'elapsed': 2, 'min_green': 10, 'preempt_min_green': 4, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'none', 'ped_elapsed': 0, 'ped_truncate': False, 'track_current': True}, [4, 0]), ({'state': 'green', 'elapsed': 18, 'min_green': 15, 'preempt_min_green': 7, 'yellow': 4, 'red': 1, 'fdw': 15, 'ped': 'walk', 'ped_elapsed': 8, 'ped_truncate': True, 'track_current': False}, [5, 0]), ({'state': 'yellow', 'elapsed': 4, 'min_green': 16, 'preempt_min_green': 3, 'yellow': 5, 'red': 3, 'fdw': 14, 'ped': 'none', 'ped_elapsed': 19, 'ped_truncate': False, 'track_current': False}, [4, 0]), ({'state': 'yellow', 'elapsed': 12, 'min_green': 14, 'preempt_min_green': 3, 'yellow': 3, 'red': 2, 'fdw': 23, 'ped': 'none', 'ped_elapsed': 6, 'ped_truncate': True, 'track_current': True}, [2, 0]), ({'state': 'red', 'elapsed': 7, 'min_green': 9, 'preempt_min_green': 10, 'yellow': 3, 'red': 1, 'fdw': 9, 'ped': 'none', 'ped_elapsed': 12, 'ped_truncate': False, 'track_current': False}, [0, 0]), ({'state': 'green', 'elapsed': 1, 'min_green': 15, 'preempt_min_green': 5, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'fdw', 'ped_elapsed': 4, 'ped_truncate': False, 'track_current': False}, [14, 8]), ({'state': 'green', 'elapsed': 20, 'min_green': 18, 'preempt_min_green': 10, 'yellow': 3, 'red': 2, 'fdw': 8, 'ped': 'none', 'ped_elapsed': 7, 'ped_truncate': False, 'track_current': True}, [0, 0])], [({'state': 'green', 'elapsed': 6, 'min_green': 11, 'preempt_min_green': 6, 'yellow': 6, 'red': 3, 'fdw': 11, 'ped': 'none', 'ped_elapsed': 9, 'ped_truncate': False, 'track_current': False}, [9, 0]), ({'state': 'green', 'elapsed': 1, 'min_green': 15, 'preempt_min_green': 5, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'fdw', 'ped_elapsed': 4, 'ped_truncate': False, 'track_current': False}, [14, 8]), ({'state': 'green', 'elapsed': 9, 'min_green': 12, 'preempt_min_green': 3, 'yellow': 4, 'red': 2, 'fdw': 11, 'ped': 'none', 'ped_elapsed': 18, 'ped_truncate': False, 'track_current': False}, [6, 0]), ({'state': 'yellow', 'elapsed': 9, 'min_green': 13, 'preempt_min_green': 8, 'yellow': 5, 'red': 1, 'fdw': 10, 'ped': 'none', 'ped_elapsed': 15, 'ped_truncate': False, 'track_current': True}, [1, 0]), ({'state': 'green', 'elapsed': 10, 'min_green': 10, 'preempt_min_green': 6, 'yellow': 3, 'red': 3, 'fdw': 25, 'ped': 'walk', 'ped_elapsed': 17, 'ped_truncate': False, 'track_current': False}, [31, 25]), ({'state': 'yellow', 'elapsed': 2, 'min_green': 10, 'preempt_min_green': 4, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'none', 'ped_elapsed': 0, 'ped_truncate': False, 'track_current': True}, [4, 0]), ({'state': 'green', 'elapsed': 11, 'min_green': 10, 'preempt_min_green': 4, 'yellow': 5, 'red': 1, 'fdw': 15, 'ped': 'fdw', 'ped_elapsed': 6, 'ped_truncate': True, 'track_current': False}, [6, 0]), ({'state': 'yellow', 'elapsed': 16, 'min_green': 19, 'preempt_min_green': 3, 'yellow': 5, 'red': 2, 'fdw': 13, 'ped': 'none', 'ped_elapsed': 19, 'ped_truncate': True, 'track_current': True}, [2, 0])], [({'state': 'yellow', 'elapsed': 2, 'min_green': 10, 'preempt_min_green': 4, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'none', 'ped_elapsed': 0, 'ped_truncate': False, 'track_current': True}, [4, 0]), ({'state': 'green', 'elapsed': 12, 'min_green': 8, 'preempt_min_green': 7, 'yellow': 5, 'red': 1, 'fdw': 24, 'ped': 'walk', 'ped_elapsed': 4, 'ped_truncate': False, 'track_current': False}, [30, 24]), ({'state': 'red', 'elapsed': 0, 'min_green': 14, 'preempt_min_green': 5, 'yellow': 3, 'red': 1, 'fdw': 15, 'ped': 'none', 'ped_elapsed': 18, 'ped_truncate': False, 'track_current': True}, [1, 0]), ({'state': 'green', 'elapsed': 1, 'min_green': 15, 'preempt_min_green': 5, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'fdw', 'ped_elapsed': 4, 'ped_truncate': False, 'track_current': False}, [14, 8]), ({'state': 'green', 'elapsed': 6, 'min_green': 20, 'preempt_min_green': 9, 'yellow': 4, 'red': 3, 'fdw': 25, 'ped': 'none', 'ped_elapsed': 1, 'ped_truncate': True, 'track_current': False}, [10, 3]), ({'state': 'green', 'elapsed': 10, 'min_green': 18, 'preempt_min_green': 2, 'yellow': 3, 'red': 1, 'fdw': 20, 'ped': 'none', 'ped_elapsed': 20, 'ped_truncate': False, 'track_current': False}, [4, 0]), ({'state': 'red', 'elapsed': 18, 'min_green': 16, 'preempt_min_green': 10, 'yellow': 6, 'red': 2, 'fdw': 25, 'ped': 'none', 'ped_elapsed': 13, 'ped_truncate': False, 'track_current': False}, [0, 0]), ({'state': 'yellow', 'elapsed': 9, 'min_green': 18, 'preempt_min_green': 3, 'yellow': 6, 'red': 3, 'fdw': 15, 'ped': 'none', 'ped_elapsed': 9, 'ped_truncate': False, 'track_current': True}, [3, 0])], [({'state': 'yellow', 'elapsed': 6, 'min_green': 20, 'preempt_min_green': 5, 'yellow': 3, 'red': 3, 'fdw': 19, 'ped': 'none', 'ped_elapsed': 10, 'ped_truncate': True, 'track_current': False}, [3, 0]), ({'state': 'yellow', 'elapsed': 4, 'min_green': 20, 'preempt_min_green': 8, 'yellow': 6, 'red': 1, 'fdw': 14, 'ped': 'none', 'ped_elapsed': 11, 'ped_truncate': True, 'track_current': True}, [3, 0]), ({'state': 'yellow', 'elapsed': 2, 'min_green': 10, 'preempt_min_green': 4, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'none', 'ped_elapsed': 0, 'ped_truncate': False, 'track_current': True}, [4, 0]), ({'state': 'green', 'elapsed': 6, 'min_green': 17, 'preempt_min_green': 4, 'yellow': 4, 'red': 3, 'fdw': 25, 'ped': 'fdw', 'ped_elapsed': 1, 'ped_truncate': False, 'track_current': False}, [31, 24]), ({'state': 'red', 'elapsed': 7, 'min_green': 13, 'preempt_min_green': 2, 'yellow': 6, 'red': 1, 'fdw': 21, 'ped': 'none', 'ped_elapsed': 6, 'ped_truncate': False, 'track_current': False}, [0, 0]), ({'state': 'green', 'elapsed': 1, 'min_green': 15, 'preempt_min_green': 5, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'fdw', 'ped_elapsed': 4, 'ped_truncate': False, 'track_current': False}, [14, 8]), ({'state': 'green', 'elapsed': 2, 'min_green': 20, 'preempt_min_green': 9, 'yellow': 4, 'red': 3, 'fdw': 18, 'ped': 'none', 'ped_elapsed': 6, 'ped_truncate': False, 'track_current': False}, [14, 7]), ({'state': 'yellow', 'elapsed': 12, 'min_green': 12, 'preempt_min_green': 10, 'yellow': 5, 'red': 1, 'fdw': 19, 'ped': 'none', 'ped_elapsed': 9, 'ped_truncate': False, 'track_current': True}, [1, 0])], [({'state': 'red', 'elapsed': 1, 'min_green': 11, 'preempt_min_green': 2, 'yellow': 3, 'red': 3, 'fdw': 22, 'ped': 'none', 'ped_elapsed': 2, 'ped_truncate': True, 'track_current': False}, [2, 0]), ({'state': 'yellow', 'elapsed': 11, 'min_green': 18, 'preempt_min_green': 9, 'yellow': 6, 'red': 3, 'fdw': 25, 'ped': 'none', 'ped_elapsed': 11, 'ped_truncate': False, 'track_current': True}, [3, 0]), ({'state': 'green', 'elapsed': 12, 'min_green': 18, 'preempt_min_green': 10, 'yellow': 6, 'red': 2, 'fdw': 18, 'ped': 'fdw', 'ped_elapsed': 19, 'ped_truncate': False, 'track_current': True}, [0, 0]), ({'state': 'yellow', 'elapsed': 2, 'min_green': 10, 'preempt_min_green': 4, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'none', 'ped_elapsed': 0, 'ped_truncate': False, 'track_current': True}, [4, 0]), ({'state': 'yellow', 'elapsed': 8, 'min_green': 11, 'preempt_min_green': 7, 'yellow': 3, 'red': 3, 'fdw': 22, 'ped': 'none', 'ped_elapsed': 10, 'ped_truncate': True, 'track_current': True}, [3, 0]), ({'state': 'red', 'elapsed': 9, 'min_green': 11, 'preempt_min_green': 10, 'yellow': 5, 'red': 1, 'fdw': 20, 'ped': 'none', 'ped_elapsed': 19, 'ped_truncate': True, 'track_current': False}, [0, 0]), ({'state': 'green', 'elapsed': 1, 'min_green': 15, 'preempt_min_green': 5, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'fdw', 'ped_elapsed': 4, 'ped_truncate': False, 'track_current': False}, [14, 8]), ({'state': 'green', 'elapsed': 13, 'min_green': 14, 'preempt_min_green': 2, 'yellow': 4, 'red': 2, 'fdw': 11, 'ped': 'none', 'ped_elapsed': 19, 'ped_truncate': True, 'track_current': False}, [6, 0])]]
for i, (args, expected) in enumerate(fixtures[N-1]):
    check('timing oracle' + ' %d' % i, solve(args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
timing oracle 0[0, 0][3, 0]Failed
timing oracle 1[0, 0][4, 0]Failed
timing oracle 2[5, 0][5, 0]Passed
timing oracle 3[4, 0][4, 0]Passed
timing oracle 4[0, 0][2, 0]Failed
timing oracle 5[0, 0][0, 0]Passed
timing oracle 6[14, 8][14, 8]Passed
timing oracle 7[0, 0][0, 0]Passed

SHA-256 / 81aa2bb05ac8895116d889edd05c05f830a7d3cd23bf10ba830ac109ebc7f6e9

3 / The verified repair

Exit 0
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(x):
    st, el = x['state'], x['elapsed']
    y, r, f = x['yellow'], x['red'], x['fdw']
    if st == 'green' and x['track_current']:
        return [0, 0]
    if st == 'red':
        return [max(0, r - el), 0]
    if st == 'yellow':
        return [max(0, y - el) + r, 0]
    ped = 0
    if x['ped'] == 'walk':
        ped = 0 if x['ped_truncate'] else f
    elif x['ped'] == 'fdw':
        ped = 0 if x['ped_truncate'] else max(0, f - x['ped_elapsed'])
    hold = max(ped, max(0, x['preempt_min_green'] - el))
    return [hold + y + r, hold]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[({'state': 'yellow', 'elapsed': 18, 'min_green': 19, 'preempt_min_green': 6, 'yellow': 5, 'red': 3, 'fdw': 21, 'ped': 'none', 'ped_elapsed': 0, 'ped_truncate': True, 'track_current': True}, [3, 0]), ({'state': 'yellow', 'elapsed': 2, 'min_green': 10, 'preempt_min_green': 4, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'none', 'ped_elapsed': 0, 'ped_truncate': False, 'track_current': True}, [4, 0]), ({'state': 'green', 'elapsed': 18, 'min_green': 15, 'preempt_min_green': 7, 'yellow': 4, 'red': 1, 'fdw': 15, 'ped': 'walk', 'ped_elapsed': 8, 'ped_truncate': True, 'track_current': False}, [5, 0]), ({'state': 'yellow', 'elapsed': 4, 'min_green': 16, 'preempt_min_green': 3, 'yellow': 5, 'red': 3, 'fdw': 14, 'ped': 'none', 'ped_elapsed': 19, 'ped_truncate': False, 'track_current': False}, [4, 0]), ({'state': 'yellow', 'elapsed': 12, 'min_green': 14, 'preempt_min_green': 3, 'yellow': 3, 'red': 2, 'fdw': 23, 'ped': 'none', 'ped_elapsed': 6, 'ped_truncate': True, 'track_current': True}, [2, 0]), ({'state': 'red', 'elapsed': 7, 'min_green': 9, 'preempt_min_green': 10, 'yellow': 3, 'red': 1, 'fdw': 9, 'ped': 'none', 'ped_elapsed': 12, 'ped_truncate': False, 'track_current': False}, [0, 0]), ({'state': 'green', 'elapsed': 1, 'min_green': 15, 'preempt_min_green': 5, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'fdw', 'ped_elapsed': 4, 'ped_truncate': False, 'track_current': False}, [14, 8]), ({'state': 'green', 'elapsed': 20, 'min_green': 18, 'preempt_min_green': 10, 'yellow': 3, 'red': 2, 'fdw': 8, 'ped': 'none', 'ped_elapsed': 7, 'ped_truncate': False, 'track_current': True}, [0, 0])], [({'state': 'green', 'elapsed': 6, 'min_green': 11, 'preempt_min_green': 6, 'yellow': 6, 'red': 3, 'fdw': 11, 'ped': 'none', 'ped_elapsed': 9, 'ped_truncate': False, 'track_current': False}, [9, 0]), ({'state': 'green', 'elapsed': 1, 'min_green': 15, 'preempt_min_green': 5, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'fdw', 'ped_elapsed': 4, 'ped_truncate': False, 'track_current': False}, [14, 8]), ({'state': 'green', 'elapsed': 9, 'min_green': 12, 'preempt_min_green': 3, 'yellow': 4, 'red': 2, 'fdw': 11, 'ped': 'none', 'ped_elapsed': 18, 'ped_truncate': False, 'track_current': False}, [6, 0]), ({'state': 'yellow', 'elapsed': 9, 'min_green': 13, 'preempt_min_green': 8, 'yellow': 5, 'red': 1, 'fdw': 10, 'ped': 'none', 'ped_elapsed': 15, 'ped_truncate': False, 'track_current': True}, [1, 0]), ({'state': 'green', 'elapsed': 10, 'min_green': 10, 'preempt_min_green': 6, 'yellow': 3, 'red': 3, 'fdw': 25, 'ped': 'walk', 'ped_elapsed': 17, 'ped_truncate': False, 'track_current': False}, [31, 25]), ({'state': 'yellow', 'elapsed': 2, 'min_green': 10, 'preempt_min_green': 4, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'none', 'ped_elapsed': 0, 'ped_truncate': False, 'track_current': True}, [4, 0]), ({'state': 'green', 'elapsed': 11, 'min_green': 10, 'preempt_min_green': 4, 'yellow': 5, 'red': 1, 'fdw': 15, 'ped': 'fdw', 'ped_elapsed': 6, 'ped_truncate': True, 'track_current': False}, [6, 0]), ({'state': 'yellow', 'elapsed': 16, 'min_green': 19, 'preempt_min_green': 3, 'yellow': 5, 'red': 2, 'fdw': 13, 'ped': 'none', 'ped_elapsed': 19, 'ped_truncate': True, 'track_current': True}, [2, 0])], [({'state': 'yellow', 'elapsed': 2, 'min_green': 10, 'preempt_min_green': 4, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'none', 'ped_elapsed': 0, 'ped_truncate': False, 'track_current': True}, [4, 0]), ({'state': 'green', 'elapsed': 12, 'min_green': 8, 'preempt_min_green': 7, 'yellow': 5, 'red': 1, 'fdw': 24, 'ped': 'walk', 'ped_elapsed': 4, 'ped_truncate': False, 'track_current': False}, [30, 24]), ({'state': 'red', 'elapsed': 0, 'min_green': 14, 'preempt_min_green': 5, 'yellow': 3, 'red': 1, 'fdw': 15, 'ped': 'none', 'ped_elapsed': 18, 'ped_truncate': False, 'track_current': True}, [1, 0]), ({'state': 'green', 'elapsed': 1, 'min_green': 15, 'preempt_min_green': 5, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'fdw', 'ped_elapsed': 4, 'ped_truncate': False, 'track_current': False}, [14, 8]), ({'state': 'green', 'elapsed': 6, 'min_green': 20, 'preempt_min_green': 9, 'yellow': 4, 'red': 3, 'fdw': 25, 'ped': 'none', 'ped_elapsed': 1, 'ped_truncate': True, 'track_current': False}, [10, 3]), ({'state': 'green', 'elapsed': 10, 'min_green': 18, 'preempt_min_green': 2, 'yellow': 3, 'red': 1, 'fdw': 20, 'ped': 'none', 'ped_elapsed': 20, 'ped_truncate': False, 'track_current': False}, [4, 0]), ({'state': 'red', 'elapsed': 18, 'min_green': 16, 'preempt_min_green': 10, 'yellow': 6, 'red': 2, 'fdw': 25, 'ped': 'none', 'ped_elapsed': 13, 'ped_truncate': False, 'track_current': False}, [0, 0]), ({'state': 'yellow', 'elapsed': 9, 'min_green': 18, 'preempt_min_green': 3, 'yellow': 6, 'red': 3, 'fdw': 15, 'ped': 'none', 'ped_elapsed': 9, 'ped_truncate': False, 'track_current': True}, [3, 0])], [({'state': 'yellow', 'elapsed': 6, 'min_green': 20, 'preempt_min_green': 5, 'yellow': 3, 'red': 3, 'fdw': 19, 'ped': 'none', 'ped_elapsed': 10, 'ped_truncate': True, 'track_current': False}, [3, 0]), ({'state': 'yellow', 'elapsed': 4, 'min_green': 20, 'preempt_min_green': 8, 'yellow': 6, 'red': 1, 'fdw': 14, 'ped': 'none', 'ped_elapsed': 11, 'ped_truncate': True, 'track_current': True}, [3, 0]), ({'state': 'yellow', 'elapsed': 2, 'min_green': 10, 'preempt_min_green': 4, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'none', 'ped_elapsed': 0, 'ped_truncate': False, 'track_current': True}, [4, 0]), ({'state': 'green', 'elapsed': 6, 'min_green': 17, 'preempt_min_green': 4, 'yellow': 4, 'red': 3, 'fdw': 25, 'ped': 'fdw', 'ped_elapsed': 1, 'ped_truncate': False, 'track_current': False}, [31, 24]), ({'state': 'red', 'elapsed': 7, 'min_green': 13, 'preempt_min_green': 2, 'yellow': 6, 'red': 1, 'fdw': 21, 'ped': 'none', 'ped_elapsed': 6, 'ped_truncate': False, 'track_current': False}, [0, 0]), ({'state': 'green', 'elapsed': 1, 'min_green': 15, 'preempt_min_green': 5, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'fdw', 'ped_elapsed': 4, 'ped_truncate': False, 'track_current': False}, [14, 8]), ({'state': 'green', 'elapsed': 2, 'min_green': 20, 'preempt_min_green': 9, 'yellow': 4, 'red': 3, 'fdw': 18, 'ped': 'none', 'ped_elapsed': 6, 'ped_truncate': False, 'track_current': False}, [14, 7]), ({'state': 'yellow', 'elapsed': 12, 'min_green': 12, 'preempt_min_green': 10, 'yellow': 5, 'red': 1, 'fdw': 19, 'ped': 'none', 'ped_elapsed': 9, 'ped_truncate': False, 'track_current': True}, [1, 0])], [({'state': 'red', 'elapsed': 1, 'min_green': 11, 'preempt_min_green': 2, 'yellow': 3, 'red': 3, 'fdw': 22, 'ped': 'none', 'ped_elapsed': 2, 'ped_truncate': True, 'track_current': False}, [2, 0]), ({'state': 'yellow', 'elapsed': 11, 'min_green': 18, 'preempt_min_green': 9, 'yellow': 6, 'red': 3, 'fdw': 25, 'ped': 'none', 'ped_elapsed': 11, 'ped_truncate': False, 'track_current': True}, [3, 0]), ({'state': 'green', 'elapsed': 12, 'min_green': 18, 'preempt_min_green': 10, 'yellow': 6, 'red': 2, 'fdw': 18, 'ped': 'fdw', 'ped_elapsed': 19, 'ped_truncate': False, 'track_current': True}, [0, 0]), ({'state': 'yellow', 'elapsed': 2, 'min_green': 10, 'preempt_min_green': 4, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'none', 'ped_elapsed': 0, 'ped_truncate': False, 'track_current': True}, [4, 0]), ({'state': 'yellow', 'elapsed': 8, 'min_green': 11, 'preempt_min_green': 7, 'yellow': 3, 'red': 3, 'fdw': 22, 'ped': 'none', 'ped_elapsed': 10, 'ped_truncate': True, 'track_current': True}, [3, 0]), ({'state': 'red', 'elapsed': 9, 'min_green': 11, 'preempt_min_green': 10, 'yellow': 5, 'red': 1, 'fdw': 20, 'ped': 'none', 'ped_elapsed': 19, 'ped_truncate': True, 'track_current': False}, [0, 0]), ({'state': 'green', 'elapsed': 1, 'min_green': 15, 'preempt_min_green': 5, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'fdw', 'ped_elapsed': 4, 'ped_truncate': False, 'track_current': False}, [14, 8]), ({'state': 'green', 'elapsed': 13, 'min_green': 14, 'preempt_min_green': 2, 'yellow': 4, 'red': 2, 'fdw': 11, 'ped': 'none', 'ped_elapsed': 19, 'ped_truncate': True, 'track_current': False}, [6, 0])]]
for i, (args, expected) in enumerate(fixtures[N-1]):
    check('timing oracle' + ' %d' % i, solve(args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
timing oracle 0[3, 0][3, 0]Passed
timing oracle 1[4, 0][4, 0]Passed
timing oracle 2[5, 0][5, 0]Passed
timing oracle 3[4, 0][4, 0]Passed
timing oracle 4[2, 0][2, 0]Passed
timing oracle 5[0, 0][0, 0]Passed
timing oracle 6[14, 8][14, 8]Passed
timing oracle 7[0, 0][0, 0]Passed

SHA-256 / dbf5c6bcb95098ed2f4a72ffb92e7f5602adee9654d135f6e2f34f2105bfca7b

Verification & scope

A deterministic, bounded toy model with a stipulated contract; it makes no claim of conformance to any agency manual or standard. 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.

Observations recorded using Python 3.12.14 at 2026-09-29T14:47:59.853281+00:00.

Case digest / bae8a8572ed49a6376f05b4f929c42da078f157893a94843f258efffd4f0e865