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FA-67921 / Traffic signal timing plans / Open access

Yellow and all-red intervals: reaction time in tenths is read as hundredths · case 01

Yellow and all-red intervals returns a wrong result when reaction time in tenths is read as hundredths.

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

ROOT CAUSE

Dividing by 100 makes a 1.0 s reaction time 0.1 s, shortening every yellow.

VERIFIED REPAIR

Restore the perception reaction time rule so that the step reads `Fraction(x['reaction_tenths'], 10)`.

Unsuccessful approach: Integer-dividing to whole seconds drops fractional reaction times such as 1.5 s.

Case contract

Input {speed_mph, grade_pct (uphill positive), reaction_tenths, decel ft/s^2, width_ft, veh_len_ft, crosswalk_ft, ped}. v = 1.467*speed ft/s; yellow = t + v/(2a + 2*32.2*grade/100), rounded UP to 0.1 s and clamped to [3.0, 6.0]; a non-positive denominator returns 'invalid'. All-red = (W + vehicle length)/v where W includes the far crosswalk when ped is true, rounded UP to 0.1 s and clamped to [1.0, 6.0]. Return tenths.

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
from fractions import Fraction
import math
N = 1
observations = []
def solve(x):
    v = Fraction(x['speed_mph']) * Fraction(1467, 1000)
    t = Fraction(x['reaction_tenths'], 100)
    den = 2 * x['decel'] + 2 * Fraction(322, 10) * Fraction(x['grade_pct'], 100)
    if den <= 0:
        return 'invalid'
    yl = max(30, min(60, math.ceil((t + v / den) * 10)))
    w = x['width_ft'] + (x['crosswalk_ft'] if x['ped'] else 0)
    rd = max(10, min(60, math.ceil((w + x['veh_len_ft']) / v * 10)))
    return {'yellow_tenths': yl, 'red_tenths': rd}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[({'speed_mph': 55, 'grade_pct': -7, 'reaction_tenths': 12, 'decel': 11, 'width_ft': 81, 'veh_len_ft': 40, 'crosswalk_ft': 15, 'ped': True}, {'yellow_tenths': 59, 'red_tenths': 17}), ({'speed_mph': 30, 'grade_pct': 4, 'reaction_tenths': 15, 'decel': 11, 'width_ft': 62, 'veh_len_ft': 16, 'crosswalk_ft': 8, 'ped': False}, {'yellow_tenths': 33, 'red_tenths': 18}), ({'speed_mph': 65, 'grade_pct': -7, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 120, 'veh_len_ft': 20, 'crosswalk_ft': 10, 'ped': True}, {'yellow_tenths': 60, 'red_tenths': 16}), ({'speed_mph': 20, 'grade_pct': -2, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 95, 'veh_len_ft': 20, 'crosswalk_ft': 15, 'ped': False}, {'yellow_tenths': 30, 'red_tenths': 40}), ({'speed_mph': 30, 'grade_pct': 4, 'reaction_tenths': 8, 'decel': 10, 'width_ft': 97, 'veh_len_ft': 20, 'crosswalk_ft': 12, 'ped': False}, {'yellow_tenths': 30, 'red_tenths': 27}), ({'speed_mph': 45, 'grade_pct': -4, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 80, 'veh_len_ft': 20, 'crosswalk_ft': 10, 'ped': True}, {'yellow_tenths': 48, 'red_tenths': 17}), ({'speed_mph': 20, 'grade_pct': -4, 'reaction_tenths': 12, 'decel': 11, 'width_ft': 61, 'veh_len_ft': 16, 'crosswalk_ft': 12, 'ped': False}, {'yellow_tenths': 30, 'red_tenths': 27}), ({'speed_mph': 30, 'grade_pct': 0, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 60, 'veh_len_ft': 20, 'crosswalk_ft': 12, 'ped': False}, {'yellow_tenths': 33, 'red_tenths': 19})], [({'speed_mph': 30, 'grade_pct': 6, 'reaction_tenths': 10, 'decel': 11, 'width_ft': 63, 'veh_len_ft': 20, 'crosswalk_ft': 15, 'ped': True}, {'yellow_tenths': 30, 'red_tenths': 23}), ({'speed_mph': 20, 'grade_pct': -4, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 49, 'veh_len_ft': 25, 'crosswalk_ft': 15, 'ped': True}, {'yellow_tenths': 30, 'red_tenths': 31}), ({'speed_mph': 20, 'grade_pct': -8, 'reaction_tenths': 10, 'decel': 11, 'width_ft': 61, 'veh_len_ft': 40, 'crosswalk_ft': 15, 'ped': True}, {'yellow_tenths': 30, 'red_tenths': 40}), ({'speed_mph': 45, 'grade_pct': 2, 'reaction_tenths': 12, 'decel': 10, 'width_ft': 65, 'veh_len_ft': 25, 'crosswalk_ft': 10, 'ped': False}, {'yellow_tenths': 44, 'red_tenths': 14}), ({'speed_mph': 65, 'grade_pct': -7, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 120, 'veh_len_ft': 20, 'crosswalk_ft': 10, 'ped': True}, {'yellow_tenths': 60, 'red_tenths': 16}), ({'speed_mph': 25, 'grade_pct': 3, 'reaction_tenths': 15, 'decel': 11, 'width_ft': 74, 'veh_len_ft': 20, 'crosswalk_ft': 8, 'ped': False}, {'yellow_tenths': 31, 'red_tenths': 26}), ({'speed_mph': 45, 'grade_pct': -4, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 80, 'veh_len_ft': 20, 'crosswalk_ft': 10, 'ped': True}, {'yellow_tenths': 48, 'red_tenths': 17}), ({'speed_mph': 30, 'grade_pct': 0, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 60, 'veh_len_ft': 20, 'crosswalk_ft': 12, 'ped': False}, {'yellow_tenths': 33, 'red_tenths': 19})], [({'speed_mph': 65, 'grade_pct': 6, 'reaction_tenths': 8, 'decel': 12, 'width_ft': 78, 'veh_len_ft': 16, 'crosswalk_ft': 15, 'ped': False}, {'yellow_tenths': 43, 'red_tenths': 10}), ({'speed_mph': 60, 'grade_pct': -6, 'reaction_tenths': 12, 'decel': 8, 'width_ft': 103, 'veh_len_ft': 40, 'crosswalk_ft': 10, 'ped': True}, {'yellow_tenths': 60, 'red_tenths': 18}), ({'speed_mph': 45, 'grade_pct': -4, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 80, 'veh_len_ft': 20, 'crosswalk_ft': 10, 'ped': True}, {'yellow_tenths': 48, 'red_tenths': 17}), ({'speed_mph': 70, 'grade_pct': -6, 'reaction_tenths': 10, 'decel': 8, 'width_ft': 114, 'veh_len_ft': 20, 'crosswalk_ft': 15, 'ped': False}, {'yellow_tenths': 60, 'red_tenths': 14}), ({'speed_mph': 65, 'grade_pct': -7, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 120, 'veh_len_ft': 20, 'crosswalk_ft': 10, 'ped': True}, {'yellow_tenths': 60, 'red_tenths': 16}), ({'speed_mph': 50, 'grade_pct': 5, 'reaction_tenths': 12, 'decel': 8, 'width_ft': 120, 'veh_len_ft': 16, 'crosswalk_ft': 12, 'ped': True}, {'yellow_tenths': 51, 'red_tenths': 21}), ({'speed_mph': 20, 'grade_pct': 1, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 118, 'veh_len_ft': 20, 'crosswalk_ft': 10, 'ped': False}, {'yellow_tenths': 30, 'red_tenths': 48}), ({'speed_mph': 30, 'grade_pct': 0, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 60, 'veh_len_ft': 20, 'crosswalk_ft': 12, 'ped': False}, {'yellow_tenths': 33, 'red_tenths': 19})], [({'speed_mph': 20, 'grade_pct': -7, 'reaction_tenths': 10, 'decel': 12, 'width_ft': 112, 'veh_len_ft': 20, 'crosswalk_ft': 15, 'ped': True}, {'yellow_tenths': 30, 'red_tenths': 51}), ({'speed_mph': 45, 'grade_pct': -8, 'reaction_tenths': 12, 'decel': 8, 'width_ft': 44, 'veh_len_ft': 20, 'crosswalk_ft': 15, 'ped': False}, {'yellow_tenths': 60, 'red_tenths': 10}), ({'speed_mph': 30, 'grade_pct': 0, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 60, 'veh_len_ft': 20, 'crosswalk_ft': 12, 'ped': False}, {'yellow_tenths': 33, 'red_tenths': 19}), ({'speed_mph': 45, 'grade_pct': -4, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 80, 'veh_len_ft': 20, 'crosswalk_ft': 10, 'ped': True}, {'yellow_tenths': 48, 'red_tenths': 17}), ({'speed_mph': 20, 'grade_pct': 8, 'reaction_tenths': 15, 'decel': 10, 'width_ft': 117, 'veh_len_ft': 20, 'crosswalk_ft': 10, 'ped': True}, {'yellow_tenths': 30, 'red_tenths': 51}), ({'speed_mph': 65, 'grade_pct': -7, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 120, 'veh_len_ft': 20, 'crosswalk_ft': 10, 'ped': True}, {'yellow_tenths': 60, 'red_tenths': 16}), ({'speed_mph': 70, 'grade_pct': 6, 'reaction_tenths': 15, 'decel': 11, 'width_ft': 56, 'veh_len_ft': 20, 'crosswalk_ft': 10, 'ped': True}, {'yellow_tenths': 55, 'red_tenths': 10}), ({'speed_mph': 65, 'grade_pct': -4, 'reaction_tenths': 8, 'decel': 11, 'width_ft': 126, 'veh_len_ft': 40, 'crosswalk_ft': 15, 'ped': False}, {'yellow_tenths': 58, 'red_tenths': 18})], [({'speed_mph': 25, 'grade_pct': -6, 'reaction_tenths': 15, 'decel': 8, 'width_ft': 126, 'veh_len_ft': 25, 'crosswalk_ft': 12, 'ped': True}, {'yellow_tenths': 46, 'red_tenths': 45}), ({'speed_mph': 65, 'grade_pct': -7, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 120, 'veh_len_ft': 20, 'crosswalk_ft': 10, 'ped': True}, {'yellow_tenths': 60, 'red_tenths': 16}), ({'speed_mph': 20, 'grade_pct': 6, 'reaction_tenths': 8, 'decel': 10, 'width_ft': 66, 'veh_len_ft': 40, 'crosswalk_ft': 12, 'ped': True}, {'yellow_tenths': 30, 'red_tenths': 41}), ({'speed_mph': 45, 'grade_pct': -4, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 80, 'veh_len_ft': 20, 'crosswalk_ft': 10, 'ped': True}, {'yellow_tenths': 48, 'red_tenths': 17}), ({'speed_mph': 30, 'grade_pct': 0, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 60, 'veh_len_ft': 20, 'crosswalk_ft': 12, 'ped': False}, {'yellow_tenths': 33, 'red_tenths': 19}), ({'speed_mph': 65, 'grade_pct': 0, 'reaction_tenths': 15, 'decel': 12, 'width_ft': 55, 'veh_len_ft': 20, 'crosswalk_ft': 10, 'ped': True}, {'yellow_tenths': 55, 'red_tenths': 10}), ({'speed_mph': 25, 'grade_pct': 7, 'reaction_tenths': 12, 'decel': 11, 'width_ft': 93, 'veh_len_ft': 25, 'crosswalk_ft': 12, 'ped': False}, {'yellow_tenths': 30, 'red_tenths': 33}), ({'speed_mph': 25, 'grade_pct': 7, 'reaction_tenths': 10, 'decel': 8, 'width_ft': 96, 'veh_len_ft': 20, 'crosswalk_ft': 12, 'ped': False}, {'yellow_tenths': 30, 'red_tenths': 32})]]
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{'red_tenths': 17, 'yellow_tenths': 48}{'red_tenths': 17, 'yellow_tenths': 59}Failed
timing oracle 1{'red_tenths': 18, 'yellow_tenths': 30}{'red_tenths': 18, 'yellow_tenths': 33}Failed
timing oracle 2{'red_tenths': 16, 'yellow_tenths': 60}{'red_tenths': 16, 'yellow_tenths': 60}Passed
timing oracle 3{'red_tenths': 40, 'yellow_tenths': 30}{'red_tenths': 40, 'yellow_tenths': 30}Passed
timing oracle 4{'red_tenths': 27, 'yellow_tenths': 30}{'red_tenths': 27, 'yellow_tenths': 30}Passed
timing oracle 5{'red_tenths': 17, 'yellow_tenths': 39}{'red_tenths': 17, 'yellow_tenths': 48}Failed
timing oracle 6{'red_tenths': 27, 'yellow_tenths': 30}{'red_tenths': 27, 'yellow_tenths': 30}Passed
timing oracle 7{'red_tenths': 19, 'yellow_tenths': 30}{'red_tenths': 19, 'yellow_tenths': 33}Failed

SHA-256 / 9ec6fdbf6b4e53fba5b0c7a24714fd9d8a4611a6ca138a8af0e3a1ce7b2f4d9d

2 / The unsuccessful fix

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json
from fractions import Fraction
import math
N = 1
observations = []
def solve(x):
    v = Fraction(x['speed_mph']) * Fraction(1467, 1000)
    t = Fraction(x['reaction_tenths'] // 10)
    den = 2 * x['decel'] + 2 * Fraction(322, 10) * Fraction(x['grade_pct'], 100)
    if den <= 0:
        return 'invalid'
    yl = max(30, min(60, math.ceil((t + v / den) * 10)))
    w = x['width_ft'] + (x['crosswalk_ft'] if x['ped'] else 0)
    rd = max(10, min(60, math.ceil((w + x['veh_len_ft']) / v * 10)))
    return {'yellow_tenths': yl, 'red_tenths': rd}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[({'speed_mph': 55, 'grade_pct': -7, 'reaction_tenths': 12, 'decel': 11, 'width_ft': 81, 'veh_len_ft': 40, 'crosswalk_ft': 15, 'ped': True}, {'yellow_tenths': 59, 'red_tenths': 17}), ({'speed_mph': 30, 'grade_pct': 4, 'reaction_tenths': 15, 'decel': 11, 'width_ft': 62, 'veh_len_ft': 16, 'crosswalk_ft': 8, 'ped': False}, {'yellow_tenths': 33, 'red_tenths': 18}), ({'speed_mph': 65, 'grade_pct': -7, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 120, 'veh_len_ft': 20, 'crosswalk_ft': 10, 'ped': True}, {'yellow_tenths': 60, 'red_tenths': 16}), ({'speed_mph': 20, 'grade_pct': -2, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 95, 'veh_len_ft': 20, 'crosswalk_ft': 15, 'ped': False}, {'yellow_tenths': 30, 'red_tenths': 40}), ({'speed_mph': 30, 'grade_pct': 4, 'reaction_tenths': 8, 'decel': 10, 'width_ft': 97, 'veh_len_ft': 20, 'crosswalk_ft': 12, 'ped': False}, {'yellow_tenths': 30, 'red_tenths': 27}), ({'speed_mph': 45, 'grade_pct': -4, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 80, 'veh_len_ft': 20, 'crosswalk_ft': 10, 'ped': True}, {'yellow_tenths': 48, 'red_tenths': 17}), ({'speed_mph': 20, 'grade_pct': -4, 'reaction_tenths': 12, 'decel': 11, 'width_ft': 61, 'veh_len_ft': 16, 'crosswalk_ft': 12, 'ped': False}, {'yellow_tenths': 30, 'red_tenths': 27}), ({'speed_mph': 30, 'grade_pct': 0, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 60, 'veh_len_ft': 20, 'crosswalk_ft': 12, 'ped': False}, {'yellow_tenths': 33, 'red_tenths': 19})], [({'speed_mph': 30, 'grade_pct': 6, 'reaction_tenths': 10, 'decel': 11, 'width_ft': 63, 'veh_len_ft': 20, 'crosswalk_ft': 15, 'ped': True}, {'yellow_tenths': 30, 'red_tenths': 23}), ({'speed_mph': 20, 'grade_pct': -4, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 49, 'veh_len_ft': 25, 'crosswalk_ft': 15, 'ped': True}, {'yellow_tenths': 30, 'red_tenths': 31}), ({'speed_mph': 20, 'grade_pct': -8, 'reaction_tenths': 10, 'decel': 11, 'width_ft': 61, 'veh_len_ft': 40, 'crosswalk_ft': 15, 'ped': True}, {'yellow_tenths': 30, 'red_tenths': 40}), ({'speed_mph': 45, 'grade_pct': 2, 'reaction_tenths': 12, 'decel': 10, 'width_ft': 65, 'veh_len_ft': 25, 'crosswalk_ft': 10, 'ped': False}, {'yellow_tenths': 44, 'red_tenths': 14}), ({'speed_mph': 65, 'grade_pct': -7, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 120, 'veh_len_ft': 20, 'crosswalk_ft': 10, 'ped': True}, {'yellow_tenths': 60, 'red_tenths': 16}), ({'speed_mph': 25, 'grade_pct': 3, 'reaction_tenths': 15, 'decel': 11, 'width_ft': 74, 'veh_len_ft': 20, 'crosswalk_ft': 8, 'ped': False}, {'yellow_tenths': 31, 'red_tenths': 26}), ({'speed_mph': 45, 'grade_pct': -4, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 80, 'veh_len_ft': 20, 'crosswalk_ft': 10, 'ped': True}, {'yellow_tenths': 48, 'red_tenths': 17}), ({'speed_mph': 30, 'grade_pct': 0, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 60, 'veh_len_ft': 20, 'crosswalk_ft': 12, 'ped': False}, {'yellow_tenths': 33, 'red_tenths': 19})], [({'speed_mph': 65, 'grade_pct': 6, 'reaction_tenths': 8, 'decel': 12, 'width_ft': 78, 'veh_len_ft': 16, 'crosswalk_ft': 15, 'ped': False}, {'yellow_tenths': 43, 'red_tenths': 10}), ({'speed_mph': 60, 'grade_pct': -6, 'reaction_tenths': 12, 'decel': 8, 'width_ft': 103, 'veh_len_ft': 40, 'crosswalk_ft': 10, 'ped': True}, {'yellow_tenths': 60, 'red_tenths': 18}), ({'speed_mph': 45, 'grade_pct': -4, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 80, 'veh_len_ft': 20, 'crosswalk_ft': 10, 'ped': True}, {'yellow_tenths': 48, 'red_tenths': 17}), ({'speed_mph': 70, 'grade_pct': -6, 'reaction_tenths': 10, 'decel': 8, 'width_ft': 114, 'veh_len_ft': 20, 'crosswalk_ft': 15, 'ped': False}, {'yellow_tenths': 60, 'red_tenths': 14}), ({'speed_mph': 65, 'grade_pct': -7, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 120, 'veh_len_ft': 20, 'crosswalk_ft': 10, 'ped': True}, {'yellow_tenths': 60, 'red_tenths': 16}), ({'speed_mph': 50, 'grade_pct': 5, 'reaction_tenths': 12, 'decel': 8, 'width_ft': 120, 'veh_len_ft': 16, 'crosswalk_ft': 12, 'ped': True}, {'yellow_tenths': 51, 'red_tenths': 21}), ({'speed_mph': 20, 'grade_pct': 1, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 118, 'veh_len_ft': 20, 'crosswalk_ft': 10, 'ped': False}, {'yellow_tenths': 30, 'red_tenths': 48}), ({'speed_mph': 30, 'grade_pct': 0, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 60, 'veh_len_ft': 20, 'crosswalk_ft': 12, 'ped': False}, {'yellow_tenths': 33, 'red_tenths': 19})], [({'speed_mph': 20, 'grade_pct': -7, 'reaction_tenths': 10, 'decel': 12, 'width_ft': 112, 'veh_len_ft': 20, 'crosswalk_ft': 15, 'ped': True}, {'yellow_tenths': 30, 'red_tenths': 51}), ({'speed_mph': 45, 'grade_pct': -8, 'reaction_tenths': 12, 'decel': 8, 'width_ft': 44, 'veh_len_ft': 20, 'crosswalk_ft': 15, 'ped': False}, {'yellow_tenths': 60, 'red_tenths': 10}), ({'speed_mph': 30, 'grade_pct': 0, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 60, 'veh_len_ft': 20, 'crosswalk_ft': 12, 'ped': False}, {'yellow_tenths': 33, 'red_tenths': 19}), ({'speed_mph': 45, 'grade_pct': -4, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 80, 'veh_len_ft': 20, 'crosswalk_ft': 10, 'ped': True}, {'yellow_tenths': 48, 'red_tenths': 17}), ({'speed_mph': 20, 'grade_pct': 8, 'reaction_tenths': 15, 'decel': 10, 'width_ft': 117, 'veh_len_ft': 20, 'crosswalk_ft': 10, 'ped': True}, {'yellow_tenths': 30, 'red_tenths': 51}), ({'speed_mph': 65, 'grade_pct': -7, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 120, 'veh_len_ft': 20, 'crosswalk_ft': 10, 'ped': True}, {'yellow_tenths': 60, 'red_tenths': 16}), ({'speed_mph': 70, 'grade_pct': 6, 'reaction_tenths': 15, 'decel': 11, 'width_ft': 56, 'veh_len_ft': 20, 'crosswalk_ft': 10, 'ped': True}, {'yellow_tenths': 55, 'red_tenths': 10}), ({'speed_mph': 65, 'grade_pct': -4, 'reaction_tenths': 8, 'decel': 11, 'width_ft': 126, 'veh_len_ft': 40, 'crosswalk_ft': 15, 'ped': False}, {'yellow_tenths': 58, 'red_tenths': 18})], [({'speed_mph': 25, 'grade_pct': -6, 'reaction_tenths': 15, 'decel': 8, 'width_ft': 126, 'veh_len_ft': 25, 'crosswalk_ft': 12, 'ped': True}, {'yellow_tenths': 46, 'red_tenths': 45}), ({'speed_mph': 65, 'grade_pct': -7, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 120, 'veh_len_ft': 20, 'crosswalk_ft': 10, 'ped': True}, {'yellow_tenths': 60, 'red_tenths': 16}), ({'speed_mph': 20, 'grade_pct': 6, 'reaction_tenths': 8, 'decel': 10, 'width_ft': 66, 'veh_len_ft': 40, 'crosswalk_ft': 12, 'ped': True}, {'yellow_tenths': 30, 'red_tenths': 41}), ({'speed_mph': 45, 'grade_pct': -4, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 80, 'veh_len_ft': 20, 'crosswalk_ft': 10, 'ped': True}, {'yellow_tenths': 48, 'red_tenths': 17}), ({'speed_mph': 30, 'grade_pct': 0, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 60, 'veh_len_ft': 20, 'crosswalk_ft': 12, 'ped': False}, {'yellow_tenths': 33, 'red_tenths': 19}), ({'speed_mph': 65, 'grade_pct': 0, 'reaction_tenths': 15, 'decel': 12, 'width_ft': 55, 'veh_len_ft': 20, 'crosswalk_ft': 10, 'ped': True}, {'yellow_tenths': 55, 'red_tenths': 10}), ({'speed_mph': 25, 'grade_pct': 7, 'reaction_tenths': 12, 'decel': 11, 'width_ft': 93, 'veh_len_ft': 25, 'crosswalk_ft': 12, 'ped': False}, {'yellow_tenths': 30, 'red_tenths': 33}), ({'speed_mph': 25, 'grade_pct': 7, 'reaction_tenths': 10, 'decel': 8, 'width_ft': 96, 'veh_len_ft': 20, 'crosswalk_ft': 12, 'ped': False}, {'yellow_tenths': 30, 'red_tenths': 32})]]
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{'red_tenths': 17, 'yellow_tenths': 57}{'red_tenths': 17, 'yellow_tenths': 59}Failed
timing oracle 1{'red_tenths': 18, 'yellow_tenths': 30}{'red_tenths': 18, 'yellow_tenths': 33}Failed
timing oracle 2{'red_tenths': 16, 'yellow_tenths': 60}{'red_tenths': 16, 'yellow_tenths': 60}Passed
timing oracle 3{'red_tenths': 40, 'yellow_tenths': 30}{'red_tenths': 40, 'yellow_tenths': 30}Passed
timing oracle 4{'red_tenths': 27, 'yellow_tenths': 30}{'red_tenths': 27, 'yellow_tenths': 30}Passed
timing oracle 5{'red_tenths': 17, 'yellow_tenths': 48}{'red_tenths': 17, 'yellow_tenths': 48}Passed
timing oracle 6{'red_tenths': 27, 'yellow_tenths': 30}{'red_tenths': 27, 'yellow_tenths': 30}Passed
timing oracle 7{'red_tenths': 19, 'yellow_tenths': 33}{'red_tenths': 19, 'yellow_tenths': 33}Passed

SHA-256 / c3bafd014d76cc62da0940edc131dfbd4ad01b5d8c1a8a134a115e11b2763e58

3 / The verified repair

Exit 0
"""Failure Map reference implementation. Python standard library only."""
import json
from fractions import Fraction
import math
N = 1
observations = []
def solve(x):
    v = Fraction(x['speed_mph']) * Fraction(1467, 1000)
    t = Fraction(x['reaction_tenths'], 10)
    den = 2 * x['decel'] + 2 * Fraction(322, 10) * Fraction(x['grade_pct'], 100)
    if den <= 0:
        return 'invalid'
    yl = max(30, min(60, math.ceil((t + v / den) * 10)))
    w = x['width_ft'] + (x['crosswalk_ft'] if x['ped'] else 0)
    rd = max(10, min(60, math.ceil((w + x['veh_len_ft']) / v * 10)))
    return {'yellow_tenths': yl, 'red_tenths': rd}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[({'speed_mph': 55, 'grade_pct': -7, 'reaction_tenths': 12, 'decel': 11, 'width_ft': 81, 'veh_len_ft': 40, 'crosswalk_ft': 15, 'ped': True}, {'yellow_tenths': 59, 'red_tenths': 17}), ({'speed_mph': 30, 'grade_pct': 4, 'reaction_tenths': 15, 'decel': 11, 'width_ft': 62, 'veh_len_ft': 16, 'crosswalk_ft': 8, 'ped': False}, {'yellow_tenths': 33, 'red_tenths': 18}), ({'speed_mph': 65, 'grade_pct': -7, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 120, 'veh_len_ft': 20, 'crosswalk_ft': 10, 'ped': True}, {'yellow_tenths': 60, 'red_tenths': 16}), ({'speed_mph': 20, 'grade_pct': -2, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 95, 'veh_len_ft': 20, 'crosswalk_ft': 15, 'ped': False}, {'yellow_tenths': 30, 'red_tenths': 40}), ({'speed_mph': 30, 'grade_pct': 4, 'reaction_tenths': 8, 'decel': 10, 'width_ft': 97, 'veh_len_ft': 20, 'crosswalk_ft': 12, 'ped': False}, {'yellow_tenths': 30, 'red_tenths': 27}), ({'speed_mph': 45, 'grade_pct': -4, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 80, 'veh_len_ft': 20, 'crosswalk_ft': 10, 'ped': True}, {'yellow_tenths': 48, 'red_tenths': 17}), ({'speed_mph': 20, 'grade_pct': -4, 'reaction_tenths': 12, 'decel': 11, 'width_ft': 61, 'veh_len_ft': 16, 'crosswalk_ft': 12, 'ped': False}, {'yellow_tenths': 30, 'red_tenths': 27}), ({'speed_mph': 30, 'grade_pct': 0, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 60, 'veh_len_ft': 20, 'crosswalk_ft': 12, 'ped': False}, {'yellow_tenths': 33, 'red_tenths': 19})], [({'speed_mph': 30, 'grade_pct': 6, 'reaction_tenths': 10, 'decel': 11, 'width_ft': 63, 'veh_len_ft': 20, 'crosswalk_ft': 15, 'ped': True}, {'yellow_tenths': 30, 'red_tenths': 23}), ({'speed_mph': 20, 'grade_pct': -4, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 49, 'veh_len_ft': 25, 'crosswalk_ft': 15, 'ped': True}, {'yellow_tenths': 30, 'red_tenths': 31}), ({'speed_mph': 20, 'grade_pct': -8, 'reaction_tenths': 10, 'decel': 11, 'width_ft': 61, 'veh_len_ft': 40, 'crosswalk_ft': 15, 'ped': True}, {'yellow_tenths': 30, 'red_tenths': 40}), ({'speed_mph': 45, 'grade_pct': 2, 'reaction_tenths': 12, 'decel': 10, 'width_ft': 65, 'veh_len_ft': 25, 'crosswalk_ft': 10, 'ped': False}, {'yellow_tenths': 44, 'red_tenths': 14}), ({'speed_mph': 65, 'grade_pct': -7, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 120, 'veh_len_ft': 20, 'crosswalk_ft': 10, 'ped': True}, {'yellow_tenths': 60, 'red_tenths': 16}), ({'speed_mph': 25, 'grade_pct': 3, 'reaction_tenths': 15, 'decel': 11, 'width_ft': 74, 'veh_len_ft': 20, 'crosswalk_ft': 8, 'ped': False}, {'yellow_tenths': 31, 'red_tenths': 26}), ({'speed_mph': 45, 'grade_pct': -4, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 80, 'veh_len_ft': 20, 'crosswalk_ft': 10, 'ped': True}, {'yellow_tenths': 48, 'red_tenths': 17}), ({'speed_mph': 30, 'grade_pct': 0, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 60, 'veh_len_ft': 20, 'crosswalk_ft': 12, 'ped': False}, {'yellow_tenths': 33, 'red_tenths': 19})], [({'speed_mph': 65, 'grade_pct': 6, 'reaction_tenths': 8, 'decel': 12, 'width_ft': 78, 'veh_len_ft': 16, 'crosswalk_ft': 15, 'ped': False}, {'yellow_tenths': 43, 'red_tenths': 10}), ({'speed_mph': 60, 'grade_pct': -6, 'reaction_tenths': 12, 'decel': 8, 'width_ft': 103, 'veh_len_ft': 40, 'crosswalk_ft': 10, 'ped': True}, {'yellow_tenths': 60, 'red_tenths': 18}), ({'speed_mph': 45, 'grade_pct': -4, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 80, 'veh_len_ft': 20, 'crosswalk_ft': 10, 'ped': True}, {'yellow_tenths': 48, 'red_tenths': 17}), ({'speed_mph': 70, 'grade_pct': -6, 'reaction_tenths': 10, 'decel': 8, 'width_ft': 114, 'veh_len_ft': 20, 'crosswalk_ft': 15, 'ped': False}, {'yellow_tenths': 60, 'red_tenths': 14}), ({'speed_mph': 65, 'grade_pct': -7, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 120, 'veh_len_ft': 20, 'crosswalk_ft': 10, 'ped': True}, {'yellow_tenths': 60, 'red_tenths': 16}), ({'speed_mph': 50, 'grade_pct': 5, 'reaction_tenths': 12, 'decel': 8, 'width_ft': 120, 'veh_len_ft': 16, 'crosswalk_ft': 12, 'ped': True}, {'yellow_tenths': 51, 'red_tenths': 21}), ({'speed_mph': 20, 'grade_pct': 1, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 118, 'veh_len_ft': 20, 'crosswalk_ft': 10, 'ped': False}, {'yellow_tenths': 30, 'red_tenths': 48}), ({'speed_mph': 30, 'grade_pct': 0, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 60, 'veh_len_ft': 20, 'crosswalk_ft': 12, 'ped': False}, {'yellow_tenths': 33, 'red_tenths': 19})], [({'speed_mph': 20, 'grade_pct': -7, 'reaction_tenths': 10, 'decel': 12, 'width_ft': 112, 'veh_len_ft': 20, 'crosswalk_ft': 15, 'ped': True}, {'yellow_tenths': 30, 'red_tenths': 51}), ({'speed_mph': 45, 'grade_pct': -8, 'reaction_tenths': 12, 'decel': 8, 'width_ft': 44, 'veh_len_ft': 20, 'crosswalk_ft': 15, 'ped': False}, {'yellow_tenths': 60, 'red_tenths': 10}), ({'speed_mph': 30, 'grade_pct': 0, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 60, 'veh_len_ft': 20, 'crosswalk_ft': 12, 'ped': False}, {'yellow_tenths': 33, 'red_tenths': 19}), ({'speed_mph': 45, 'grade_pct': -4, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 80, 'veh_len_ft': 20, 'crosswalk_ft': 10, 'ped': True}, {'yellow_tenths': 48, 'red_tenths': 17}), ({'speed_mph': 20, 'grade_pct': 8, 'reaction_tenths': 15, 'decel': 10, 'width_ft': 117, 'veh_len_ft': 20, 'crosswalk_ft': 10, 'ped': True}, {'yellow_tenths': 30, 'red_tenths': 51}), ({'speed_mph': 65, 'grade_pct': -7, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 120, 'veh_len_ft': 20, 'crosswalk_ft': 10, 'ped': True}, {'yellow_tenths': 60, 'red_tenths': 16}), ({'speed_mph': 70, 'grade_pct': 6, 'reaction_tenths': 15, 'decel': 11, 'width_ft': 56, 'veh_len_ft': 20, 'crosswalk_ft': 10, 'ped': True}, {'yellow_tenths': 55, 'red_tenths': 10}), ({'speed_mph': 65, 'grade_pct': -4, 'reaction_tenths': 8, 'decel': 11, 'width_ft': 126, 'veh_len_ft': 40, 'crosswalk_ft': 15, 'ped': False}, {'yellow_tenths': 58, 'red_tenths': 18})], [({'speed_mph': 25, 'grade_pct': -6, 'reaction_tenths': 15, 'decel': 8, 'width_ft': 126, 'veh_len_ft': 25, 'crosswalk_ft': 12, 'ped': True}, {'yellow_tenths': 46, 'red_tenths': 45}), ({'speed_mph': 65, 'grade_pct': -7, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 120, 'veh_len_ft': 20, 'crosswalk_ft': 10, 'ped': True}, {'yellow_tenths': 60, 'red_tenths': 16}), ({'speed_mph': 20, 'grade_pct': 6, 'reaction_tenths': 8, 'decel': 10, 'width_ft': 66, 'veh_len_ft': 40, 'crosswalk_ft': 12, 'ped': True}, {'yellow_tenths': 30, 'red_tenths': 41}), ({'speed_mph': 45, 'grade_pct': -4, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 80, 'veh_len_ft': 20, 'crosswalk_ft': 10, 'ped': True}, {'yellow_tenths': 48, 'red_tenths': 17}), ({'speed_mph': 30, 'grade_pct': 0, 'reaction_tenths': 10, 'decel': 10, 'width_ft': 60, 'veh_len_ft': 20, 'crosswalk_ft': 12, 'ped': False}, {'yellow_tenths': 33, 'red_tenths': 19}), ({'speed_mph': 65, 'grade_pct': 0, 'reaction_tenths': 15, 'decel': 12, 'width_ft': 55, 'veh_len_ft': 20, 'crosswalk_ft': 10, 'ped': True}, {'yellow_tenths': 55, 'red_tenths': 10}), ({'speed_mph': 25, 'grade_pct': 7, 'reaction_tenths': 12, 'decel': 11, 'width_ft': 93, 'veh_len_ft': 25, 'crosswalk_ft': 12, 'ped': False}, {'yellow_tenths': 30, 'red_tenths': 33}), ({'speed_mph': 25, 'grade_pct': 7, 'reaction_tenths': 10, 'decel': 8, 'width_ft': 96, 'veh_len_ft': 20, 'crosswalk_ft': 12, 'ped': False}, {'yellow_tenths': 30, 'red_tenths': 32})]]
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{'red_tenths': 17, 'yellow_tenths': 59}{'red_tenths': 17, 'yellow_tenths': 59}Passed
timing oracle 1{'red_tenths': 18, 'yellow_tenths': 33}{'red_tenths': 18, 'yellow_tenths': 33}Passed
timing oracle 2{'red_tenths': 16, 'yellow_tenths': 60}{'red_tenths': 16, 'yellow_tenths': 60}Passed
timing oracle 3{'red_tenths': 40, 'yellow_tenths': 30}{'red_tenths': 40, 'yellow_tenths': 30}Passed
timing oracle 4{'red_tenths': 27, 'yellow_tenths': 30}{'red_tenths': 27, 'yellow_tenths': 30}Passed
timing oracle 5{'red_tenths': 17, 'yellow_tenths': 48}{'red_tenths': 17, 'yellow_tenths': 48}Passed
timing oracle 6{'red_tenths': 27, 'yellow_tenths': 30}{'red_tenths': 27, 'yellow_tenths': 30}Passed
timing oracle 7{'red_tenths': 19, 'yellow_tenths': 33}{'red_tenths': 19, 'yellow_tenths': 33}Passed

SHA-256 / ab592d4cb0bcca772c34507c3d6d5cbbdc24d7d399fc7810c2f9dcb787b804ee

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 2026-09-29T14:47:57.249682+00:00.

Case digest / 24f16b5c0e79cc3f38615989b2fcba1b764bbc7dd903d4c0c0b27d4095a7f441