FA-68186 / Traffic signal timing plans / Open access

Railroad preemption entry timing: an all-red in progress is timed again in full · case 01

Railroad preemption entry timing returns a wrong result when an all-red in progress is timed again in full.

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

ROOT CAUSE

The already elapsed part of the red clearance is ignored.

VERIFIED REPAIR

Restore the all-red remainder rule so that the step reads `[max(0, r - el), 0]`.

Unsuccessful approach: Adding a yellow after an all-red times a clearance that has already been shown.

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 st == 'green' and x['track_current']:
        return [0, 0]
    if st == 'red':
        return [r, 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': 'green', 'elapsed': 11, 'min_green': 14, 'preempt_min_green': 3, 'yellow': 5, 'red': 3, 'fdw': 24, 'ped': 'walk', 'ped_elapsed': 6, 'ped_truncate': False, 'track_current': False}, [32, 24]), ({'state': 'red', 'elapsed': 11, 'min_green': 16, 'preempt_min_green': 4, 'yellow': 4, 'red': 1, 'fdw': 11, 'ped': 'none', 'ped_elapsed': 18, 'ped_truncate': False, 'track_current': False}, [0, 0]), ({'state': 'red', 'elapsed': 13, 'min_green': 16, 'preempt_min_green': 9, 'yellow': 5, 'red': 1, 'fdw': 13, 'ped': 'none', 'ped_elapsed': 20, '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': 'red', 'elapsed': 12, 'min_green': 18, 'preempt_min_green': 4, 'yellow': 3, 'red': 2, 'fdw': 12, 'ped': 'none', 'ped_elapsed': 16, 'ped_truncate': True, 'track_current': False}, [0, 0]), ({'state': 'green', 'elapsed': 18, 'min_green': 20, 'preempt_min_green': 4, 'yellow': 6, 'red': 3, 'fdw': 24, 'ped': 'none', 'ped_elapsed': 7, 'ped_truncate': False, 'track_current': False}, [9, 0]), ({'state': 'green', 'elapsed': 2, 'min_green': 18, 'preempt_min_green': 7, 'yellow': 3, 'red': 1, 'fdw': 13, 'ped': 'walk', 'ped_elapsed': 0, 'ped_truncate': False, 'track_current': False}, [17, 13]), ({'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': 8, 'min_green': 11, 'preempt_min_green': 5, 'yellow': 6, 'red': 2, 'fdw': 18, 'ped': 'walk', 'ped_elapsed': 19, 'ped_truncate': False, 'track_current': True}, [0, 0]), ({'state': 'red', 'elapsed': 13, 'min_green': 15, 'preempt_min_green': 3, 'yellow': 5, 'red': 2, 'fdw': 20, 'ped': 'none', 'ped_elapsed': 17, 'ped_truncate': True, 'track_current': False}, [0, 0]), ({'state': 'green', 'elapsed': 18, 'min_green': 16, 'preempt_min_green': 8, 'yellow': 3, 'red': 1, 'fdw': 22, 'ped': 'walk', 'ped_elapsed': 9, 'ped_truncate': True, 'track_current': False}, [4, 0]), ({'state': 'yellow', 'elapsed': 14, 'min_green': 15, 'preempt_min_green': 8, 'yellow': 4, 'red': 3, 'fdw': 24, 'ped': 'none', 'ped_elapsed': 8, 'ped_truncate': False, 'track_current': False}, [3, 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': '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': 'red', 'elapsed': 12, 'min_green': 14, 'preempt_min_green': 9, 'yellow': 3, 'red': 1, 'fdw': 22, 'ped': 'none', 'ped_elapsed': 2, 'ped_truncate': True, 'track_current': False}, [0, 0]), ({'state': 'red', 'elapsed': 9, 'min_green': 20, 'preempt_min_green': 9, 'yellow': 4, 'red': 3, 'fdw': 21, 'ped': 'none', 'ped_elapsed': 9, 'ped_truncate': True, 'track_current': False}, [0, 0])], [({'state': 'green', 'elapsed': 1, 'min_green': 14, 'preempt_min_green': 9, 'yellow': 4, 'red': 1, 'fdw': 17, 'ped': 'walk', 'ped_elapsed': 0, 'ped_truncate': True, 'track_current': True}, [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': 'red', 'elapsed': 16, 'min_green': 18, 'preempt_min_green': 3, 'yellow': 3, 'red': 3, 'fdw': 18, 'ped': 'none', 'ped_elapsed': 6, 'ped_truncate': True, 'track_current': False}, [0, 0]), ({'state': 'red', 'elapsed': 11, 'min_green': 10, 'preempt_min_green': 8, 'yellow': 4, 'red': 1, 'fdw': 11, 'ped': 'none', 'ped_elapsed': 17, 'ped_truncate': True, 'track_current': False}, [0, 0]), ({'state': 'green', 'elapsed': 4, 'min_green': 13, 'preempt_min_green': 9, 'yellow': 3, 'red': 2, 'fdw': 18, 'ped': 'none', 'ped_elapsed': 20, 'ped_truncate': True, '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': 'green', 'elapsed': 12, 'min_green': 9, 'preempt_min_green': 6, 'yellow': 3, 'red': 2, 'fdw': 12, 'ped': 'walk', 'ped_elapsed': 1, 'ped_truncate': False, 'track_current': False}, [17, 12]), ({'state': 'red', 'elapsed': 16, 'min_green': 16, 'preempt_min_green': 6, 'yellow': 5, 'red': 2, 'fdw': 15, 'ped': 'none', 'ped_elapsed': 12, 'ped_truncate': True, 'track_current': False}, [0, 0])], [({'state': 'green', 'elapsed': 16, 'min_green': 14, 'preempt_min_green': 8, 'yellow': 4, 'red': 3, 'fdw': 18, 'ped': 'fdw', 'ped_elapsed': 18, 'ped_truncate': False, 'track_current': False}, [7, 0]), ({'state': 'red', 'elapsed': 2, 'min_green': 18, 'preempt_min_green': 9, 'yellow': 5, 'red': 2, 'fdw': 11, 'ped': 'none', 'ped_elapsed': 13, 'ped_truncate': True, 'track_current': False}, [0, 0]), ({'state': 'red', 'elapsed': 6, 'min_green': 17, 'preempt_min_green': 6, 'yellow': 3, 'red': 1, 'fdw': 8, 'ped': 'none', 'ped_elapsed': 10, 'ped_truncate': True, 'track_current': True}, [0, 0]), ({'state': 'yellow', 'elapsed': 4, 'min_green': 8, 'preempt_min_green': 8, 'yellow': 6, 'red': 2, 'fdw': 10, 'ped': 'none', 'ped_elapsed': 16, 'ped_truncate': False, 'track_current': False}, [4, 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': 'red', 'elapsed': 14, 'min_green': 9, 'preempt_min_green': 3, 'yellow': 6, 'red': 2, 'fdw': 13, 'ped': 'none', 'ped_elapsed': 10, 'ped_truncate': False, 'track_current': False}, [0, 0]), ({'state': 'green', 'elapsed': 10, 'min_green': 13, 'preempt_min_green': 10, 'yellow': 5, 'red': 1, 'fdw': 23, 'ped': 'fdw', 'ped_elapsed': 14, 'ped_truncate': True, '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': 'red', 'elapsed': 2, 'min_green': 10, 'preempt_min_green': 7, 'yellow': 4, 'red': 3, 'fdw': 16, 'ped': 'none', 'ped_elapsed': 9, 'ped_truncate': False, 'track_current': False}, [1, 0]), ({'state': 'red', 'elapsed': 18, 'min_green': 8, 'preempt_min_green': 4, 'yellow': 6, 'red': 1, 'fdw': 23, 'ped': 'none', 'ped_elapsed': 1, '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': 3, 'min_green': 18, 'preempt_min_green': 8, 'yellow': 4, 'red': 3, 'fdw': 13, 'ped': 'walk', 'ped_elapsed': 9, 'ped_truncate': True, 'track_current': False}, [12, 5]), ({'state': 'red', 'elapsed': 12, 'min_green': 17, 'preempt_min_green': 6, 'yellow': 6, 'red': 3, 'fdw': 10, 'ped': 'none', 'ped_elapsed': 17, 'ped_truncate': False, 'track_current': False}, [0, 0]), ({'state': 'green', 'elapsed': 9, 'min_green': 16, 'preempt_min_green': 4, 'yellow': 4, 'red': 2, 'fdw': 18, 'ped': 'none', 'ped_elapsed': 12, 'ped_truncate': True, 'track_current': False}, [6, 0]), ({'state': 'green', 'elapsed': 15, 'min_green': 10, 'preempt_min_green': 3, 'yellow': 5, 'red': 1, 'fdw': 13, 'ped': 'fdw', 'ped_elapsed': 19, 'ped_truncate': False, 'track_current': False}, [6, 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])]]
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 fixture	Actual	Expected	Outcome
timing oracle 0	`[32, 24]`	`[32, 24]`	Passed
timing oracle 1	`[1, 0]`	`[0, 0]`	Failed
timing oracle 2	`[1, 0]`	`[0, 0]`	Failed
timing oracle 3	`[14, 8]`	`[14, 8]`	Passed
timing oracle 4	`[2, 0]`	`[0, 0]`	Failed
timing oracle 5	`[9, 0]`	`[9, 0]`	Passed
timing oracle 6	`[17, 13]`	`[17, 13]`	Passed
timing oracle 7	`[4, 0]`	`[4, 0]`	Passed

SHA-256 / 00374cc5ef1dc889487761d33d85911dc7047ae65bb375d6d360a32a5f2870b3

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 == 'green' and x['track_current']:
        return [0, 0]
    if st == 'red':
        return [max(0, r - el) + y, 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': 'green', 'elapsed': 11, 'min_green': 14, 'preempt_min_green': 3, 'yellow': 5, 'red': 3, 'fdw': 24, 'ped': 'walk', 'ped_elapsed': 6, 'ped_truncate': False, 'track_current': False}, [32, 24]), ({'state': 'red', 'elapsed': 11, 'min_green': 16, 'preempt_min_green': 4, 'yellow': 4, 'red': 1, 'fdw': 11, 'ped': 'none', 'ped_elapsed': 18, 'ped_truncate': False, 'track_current': False}, [0, 0]), ({'state': 'red', 'elapsed': 13, 'min_green': 16, 'preempt_min_green': 9, 'yellow': 5, 'red': 1, 'fdw': 13, 'ped': 'none', 'ped_elapsed': 20, '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': 'red', 'elapsed': 12, 'min_green': 18, 'preempt_min_green': 4, 'yellow': 3, 'red': 2, 'fdw': 12, 'ped': 'none', 'ped_elapsed': 16, 'ped_truncate': True, 'track_current': False}, [0, 0]), ({'state': 'green', 'elapsed': 18, 'min_green': 20, 'preempt_min_green': 4, 'yellow': 6, 'red': 3, 'fdw': 24, 'ped': 'none', 'ped_elapsed': 7, 'ped_truncate': False, 'track_current': False}, [9, 0]), ({'state': 'green', 'elapsed': 2, 'min_green': 18, 'preempt_min_green': 7, 'yellow': 3, 'red': 1, 'fdw': 13, 'ped': 'walk', 'ped_elapsed': 0, 'ped_truncate': False, 'track_current': False}, [17, 13]), ({'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': 8, 'min_green': 11, 'preempt_min_green': 5, 'yellow': 6, 'red': 2, 'fdw': 18, 'ped': 'walk', 'ped_elapsed': 19, 'ped_truncate': False, 'track_current': True}, [0, 0]), ({'state': 'red', 'elapsed': 13, 'min_green': 15, 'preempt_min_green': 3, 'yellow': 5, 'red': 2, 'fdw': 20, 'ped': 'none', 'ped_elapsed': 17, 'ped_truncate': True, 'track_current': False}, [0, 0]), ({'state': 'green', 'elapsed': 18, 'min_green': 16, 'preempt_min_green': 8, 'yellow': 3, 'red': 1, 'fdw': 22, 'ped': 'walk', 'ped_elapsed': 9, 'ped_truncate': True, 'track_current': False}, [4, 0]), ({'state': 'yellow', 'elapsed': 14, 'min_green': 15, 'preempt_min_green': 8, 'yellow': 4, 'red': 3, 'fdw': 24, 'ped': 'none', 'ped_elapsed': 8, 'ped_truncate': False, 'track_current': False}, [3, 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': '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': 'red', 'elapsed': 12, 'min_green': 14, 'preempt_min_green': 9, 'yellow': 3, 'red': 1, 'fdw': 22, 'ped': 'none', 'ped_elapsed': 2, 'ped_truncate': True, 'track_current': False}, [0, 0]), ({'state': 'red', 'elapsed': 9, 'min_green': 20, 'preempt_min_green': 9, 'yellow': 4, 'red': 3, 'fdw': 21, 'ped': 'none', 'ped_elapsed': 9, 'ped_truncate': True, 'track_current': False}, [0, 0])], [({'state': 'green', 'elapsed': 1, 'min_green': 14, 'preempt_min_green': 9, 'yellow': 4, 'red': 1, 'fdw': 17, 'ped': 'walk', 'ped_elapsed': 0, 'ped_truncate': True, 'track_current': True}, [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': 'red', 'elapsed': 16, 'min_green': 18, 'preempt_min_green': 3, 'yellow': 3, 'red': 3, 'fdw': 18, 'ped': 'none', 'ped_elapsed': 6, 'ped_truncate': True, 'track_current': False}, [0, 0]), ({'state': 'red', 'elapsed': 11, 'min_green': 10, 'preempt_min_green': 8, 'yellow': 4, 'red': 1, 'fdw': 11, 'ped': 'none', 'ped_elapsed': 17, 'ped_truncate': True, 'track_current': False}, [0, 0]), ({'state': 'green', 'elapsed': 4, 'min_green': 13, 'preempt_min_green': 9, 'yellow': 3, 'red': 2, 'fdw': 18, 'ped': 'none', 'ped_elapsed': 20, 'ped_truncate': True, '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': 'green', 'elapsed': 12, 'min_green': 9, 'preempt_min_green': 6, 'yellow': 3, 'red': 2, 'fdw': 12, 'ped': 'walk', 'ped_elapsed': 1, 'ped_truncate': False, 'track_current': False}, [17, 12]), ({'state': 'red', 'elapsed': 16, 'min_green': 16, 'preempt_min_green': 6, 'yellow': 5, 'red': 2, 'fdw': 15, 'ped': 'none', 'ped_elapsed': 12, 'ped_truncate': True, 'track_current': False}, [0, 0])], [({'state': 'green', 'elapsed': 16, 'min_green': 14, 'preempt_min_green': 8, 'yellow': 4, 'red': 3, 'fdw': 18, 'ped': 'fdw', 'ped_elapsed': 18, 'ped_truncate': False, 'track_current': False}, [7, 0]), ({'state': 'red', 'elapsed': 2, 'min_green': 18, 'preempt_min_green': 9, 'yellow': 5, 'red': 2, 'fdw': 11, 'ped': 'none', 'ped_elapsed': 13, 'ped_truncate': True, 'track_current': False}, [0, 0]), ({'state': 'red', 'elapsed': 6, 'min_green': 17, 'preempt_min_green': 6, 'yellow': 3, 'red': 1, 'fdw': 8, 'ped': 'none', 'ped_elapsed': 10, 'ped_truncate': True, 'track_current': True}, [0, 0]), ({'state': 'yellow', 'elapsed': 4, 'min_green': 8, 'preempt_min_green': 8, 'yellow': 6, 'red': 2, 'fdw': 10, 'ped': 'none', 'ped_elapsed': 16, 'ped_truncate': False, 'track_current': False}, [4, 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': 'red', 'elapsed': 14, 'min_green': 9, 'preempt_min_green': 3, 'yellow': 6, 'red': 2, 'fdw': 13, 'ped': 'none', 'ped_elapsed': 10, 'ped_truncate': False, 'track_current': False}, [0, 0]), ({'state': 'green', 'elapsed': 10, 'min_green': 13, 'preempt_min_green': 10, 'yellow': 5, 'red': 1, 'fdw': 23, 'ped': 'fdw', 'ped_elapsed': 14, 'ped_truncate': True, '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': 'red', 'elapsed': 2, 'min_green': 10, 'preempt_min_green': 7, 'yellow': 4, 'red': 3, 'fdw': 16, 'ped': 'none', 'ped_elapsed': 9, 'ped_truncate': False, 'track_current': False}, [1, 0]), ({'state': 'red', 'elapsed': 18, 'min_green': 8, 'preempt_min_green': 4, 'yellow': 6, 'red': 1, 'fdw': 23, 'ped': 'none', 'ped_elapsed': 1, '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': 3, 'min_green': 18, 'preempt_min_green': 8, 'yellow': 4, 'red': 3, 'fdw': 13, 'ped': 'walk', 'ped_elapsed': 9, 'ped_truncate': True, 'track_current': False}, [12, 5]), ({'state': 'red', 'elapsed': 12, 'min_green': 17, 'preempt_min_green': 6, 'yellow': 6, 'red': 3, 'fdw': 10, 'ped': 'none', 'ped_elapsed': 17, 'ped_truncate': False, 'track_current': False}, [0, 0]), ({'state': 'green', 'elapsed': 9, 'min_green': 16, 'preempt_min_green': 4, 'yellow': 4, 'red': 2, 'fdw': 18, 'ped': 'none', 'ped_elapsed': 12, 'ped_truncate': True, 'track_current': False}, [6, 0]), ({'state': 'green', 'elapsed': 15, 'min_green': 10, 'preempt_min_green': 3, 'yellow': 5, 'red': 1, 'fdw': 13, 'ped': 'fdw', 'ped_elapsed': 19, 'ped_truncate': False, 'track_current': False}, [6, 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])]]
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 fixture	Actual	Expected	Outcome
timing oracle 0	`[32, 24]`	`[32, 24]`	Passed
timing oracle 1	`[4, 0]`	`[0, 0]`	Failed
timing oracle 2	`[5, 0]`	`[0, 0]`	Failed
timing oracle 3	`[14, 8]`	`[14, 8]`	Passed
timing oracle 4	`[3, 0]`	`[0, 0]`	Failed
timing oracle 5	`[9, 0]`	`[9, 0]`	Passed
timing oracle 6	`[17, 13]`	`[17, 13]`	Passed
timing oracle 7	`[4, 0]`	`[4, 0]`	Passed

SHA-256 / f2cd7a25caa489c0a61c4a6e4e4f16b6b12c100bd0ec7af5cb58799fc762ab5f

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': 'green', 'elapsed': 11, 'min_green': 14, 'preempt_min_green': 3, 'yellow': 5, 'red': 3, 'fdw': 24, 'ped': 'walk', 'ped_elapsed': 6, 'ped_truncate': False, 'track_current': False}, [32, 24]), ({'state': 'red', 'elapsed': 11, 'min_green': 16, 'preempt_min_green': 4, 'yellow': 4, 'red': 1, 'fdw': 11, 'ped': 'none', 'ped_elapsed': 18, 'ped_truncate': False, 'track_current': False}, [0, 0]), ({'state': 'red', 'elapsed': 13, 'min_green': 16, 'preempt_min_green': 9, 'yellow': 5, 'red': 1, 'fdw': 13, 'ped': 'none', 'ped_elapsed': 20, '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': 'red', 'elapsed': 12, 'min_green': 18, 'preempt_min_green': 4, 'yellow': 3, 'red': 2, 'fdw': 12, 'ped': 'none', 'ped_elapsed': 16, 'ped_truncate': True, 'track_current': False}, [0, 0]), ({'state': 'green', 'elapsed': 18, 'min_green': 20, 'preempt_min_green': 4, 'yellow': 6, 'red': 3, 'fdw': 24, 'ped': 'none', 'ped_elapsed': 7, 'ped_truncate': False, 'track_current': False}, [9, 0]), ({'state': 'green', 'elapsed': 2, 'min_green': 18, 'preempt_min_green': 7, 'yellow': 3, 'red': 1, 'fdw': 13, 'ped': 'walk', 'ped_elapsed': 0, 'ped_truncate': False, 'track_current': False}, [17, 13]), ({'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': 8, 'min_green': 11, 'preempt_min_green': 5, 'yellow': 6, 'red': 2, 'fdw': 18, 'ped': 'walk', 'ped_elapsed': 19, 'ped_truncate': False, 'track_current': True}, [0, 0]), ({'state': 'red', 'elapsed': 13, 'min_green': 15, 'preempt_min_green': 3, 'yellow': 5, 'red': 2, 'fdw': 20, 'ped': 'none', 'ped_elapsed': 17, 'ped_truncate': True, 'track_current': False}, [0, 0]), ({'state': 'green', 'elapsed': 18, 'min_green': 16, 'preempt_min_green': 8, 'yellow': 3, 'red': 1, 'fdw': 22, 'ped': 'walk', 'ped_elapsed': 9, 'ped_truncate': True, 'track_current': False}, [4, 0]), ({'state': 'yellow', 'elapsed': 14, 'min_green': 15, 'preempt_min_green': 8, 'yellow': 4, 'red': 3, 'fdw': 24, 'ped': 'none', 'ped_elapsed': 8, 'ped_truncate': False, 'track_current': False}, [3, 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': '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': 'red', 'elapsed': 12, 'min_green': 14, 'preempt_min_green': 9, 'yellow': 3, 'red': 1, 'fdw': 22, 'ped': 'none', 'ped_elapsed': 2, 'ped_truncate': True, 'track_current': False}, [0, 0]), ({'state': 'red', 'elapsed': 9, 'min_green': 20, 'preempt_min_green': 9, 'yellow': 4, 'red': 3, 'fdw': 21, 'ped': 'none', 'ped_elapsed': 9, 'ped_truncate': True, 'track_current': False}, [0, 0])], [({'state': 'green', 'elapsed': 1, 'min_green': 14, 'preempt_min_green': 9, 'yellow': 4, 'red': 1, 'fdw': 17, 'ped': 'walk', 'ped_elapsed': 0, 'ped_truncate': True, 'track_current': True}, [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': 'red', 'elapsed': 16, 'min_green': 18, 'preempt_min_green': 3, 'yellow': 3, 'red': 3, 'fdw': 18, 'ped': 'none', 'ped_elapsed': 6, 'ped_truncate': True, 'track_current': False}, [0, 0]), ({'state': 'red', 'elapsed': 11, 'min_green': 10, 'preempt_min_green': 8, 'yellow': 4, 'red': 1, 'fdw': 11, 'ped': 'none', 'ped_elapsed': 17, 'ped_truncate': True, 'track_current': False}, [0, 0]), ({'state': 'green', 'elapsed': 4, 'min_green': 13, 'preempt_min_green': 9, 'yellow': 3, 'red': 2, 'fdw': 18, 'ped': 'none', 'ped_elapsed': 20, 'ped_truncate': True, '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': 'green', 'elapsed': 12, 'min_green': 9, 'preempt_min_green': 6, 'yellow': 3, 'red': 2, 'fdw': 12, 'ped': 'walk', 'ped_elapsed': 1, 'ped_truncate': False, 'track_current': False}, [17, 12]), ({'state': 'red', 'elapsed': 16, 'min_green': 16, 'preempt_min_green': 6, 'yellow': 5, 'red': 2, 'fdw': 15, 'ped': 'none', 'ped_elapsed': 12, 'ped_truncate': True, 'track_current': False}, [0, 0])], [({'state': 'green', 'elapsed': 16, 'min_green': 14, 'preempt_min_green': 8, 'yellow': 4, 'red': 3, 'fdw': 18, 'ped': 'fdw', 'ped_elapsed': 18, 'ped_truncate': False, 'track_current': False}, [7, 0]), ({'state': 'red', 'elapsed': 2, 'min_green': 18, 'preempt_min_green': 9, 'yellow': 5, 'red': 2, 'fdw': 11, 'ped': 'none', 'ped_elapsed': 13, 'ped_truncate': True, 'track_current': False}, [0, 0]), ({'state': 'red', 'elapsed': 6, 'min_green': 17, 'preempt_min_green': 6, 'yellow': 3, 'red': 1, 'fdw': 8, 'ped': 'none', 'ped_elapsed': 10, 'ped_truncate': True, 'track_current': True}, [0, 0]), ({'state': 'yellow', 'elapsed': 4, 'min_green': 8, 'preempt_min_green': 8, 'yellow': 6, 'red': 2, 'fdw': 10, 'ped': 'none', 'ped_elapsed': 16, 'ped_truncate': False, 'track_current': False}, [4, 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': 'red', 'elapsed': 14, 'min_green': 9, 'preempt_min_green': 3, 'yellow': 6, 'red': 2, 'fdw': 13, 'ped': 'none', 'ped_elapsed': 10, 'ped_truncate': False, 'track_current': False}, [0, 0]), ({'state': 'green', 'elapsed': 10, 'min_green': 13, 'preempt_min_green': 10, 'yellow': 5, 'red': 1, 'fdw': 23, 'ped': 'fdw', 'ped_elapsed': 14, 'ped_truncate': True, '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': 'red', 'elapsed': 2, 'min_green': 10, 'preempt_min_green': 7, 'yellow': 4, 'red': 3, 'fdw': 16, 'ped': 'none', 'ped_elapsed': 9, 'ped_truncate': False, 'track_current': False}, [1, 0]), ({'state': 'red', 'elapsed': 18, 'min_green': 8, 'preempt_min_green': 4, 'yellow': 6, 'red': 1, 'fdw': 23, 'ped': 'none', 'ped_elapsed': 1, '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': 3, 'min_green': 18, 'preempt_min_green': 8, 'yellow': 4, 'red': 3, 'fdw': 13, 'ped': 'walk', 'ped_elapsed': 9, 'ped_truncate': True, 'track_current': False}, [12, 5]), ({'state': 'red', 'elapsed': 12, 'min_green': 17, 'preempt_min_green': 6, 'yellow': 6, 'red': 3, 'fdw': 10, 'ped': 'none', 'ped_elapsed': 17, 'ped_truncate': False, 'track_current': False}, [0, 0]), ({'state': 'green', 'elapsed': 9, 'min_green': 16, 'preempt_min_green': 4, 'yellow': 4, 'red': 2, 'fdw': 18, 'ped': 'none', 'ped_elapsed': 12, 'ped_truncate': True, 'track_current': False}, [6, 0]), ({'state': 'green', 'elapsed': 15, 'min_green': 10, 'preempt_min_green': 3, 'yellow': 5, 'red': 1, 'fdw': 13, 'ped': 'fdw', 'ped_elapsed': 19, 'ped_truncate': False, 'track_current': False}, [6, 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])]]
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 fixture	Actual	Expected	Outcome
timing oracle 0	`[32, 24]`	`[32, 24]`	Passed
timing oracle 1	`[0, 0]`	`[0, 0]`	Passed
timing oracle 2	`[0, 0]`	`[0, 0]`	Passed
timing oracle 3	`[14, 8]`	`[14, 8]`	Passed
timing oracle 4	`[0, 0]`	`[0, 0]`	Passed
timing oracle 5	`[9, 0]`	`[9, 0]`	Passed
timing oracle 6	`[17, 13]`	`[17, 13]`	Passed
timing oracle 7	`[4, 0]`	`[4, 0]`	Passed

SHA-256 / 33b9c8b5bf920e570178724ffb401becbde0534d4f45e957dc405bf746f4820e

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 2026-09-29T14:47:59.845871+00:00.

Case digest / e01bd87aa6a75b714cb84ba3f4685d2716e54ffcdb11837463c2f5a605feed4b