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FA-68151 / Traffic signal timing plans / Open access

Uniform delay level of service: oversaturation is only flagged above X = 1.1 · case 01

Uniform delay level of service returns a wrong result when oversaturation is only flagged above X = 1.1.

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

ROOT CAUSE

Exactly saturated movements (X = 1) are forced to LOS F instead of being graded by delay.

VERIFIED REPAIR

Restore the oversaturation grade rule so that the step reads `if X > 1:`.

Unsuccessful approach: A 1.1 threshold lets movements with 1 < X <= 1.1 receive a delay-based grade.

Case contract

Input {cycle, green, volume, sat_per_lane, lanes}. lam = green/cycle, capacity = sat*lanes*lam, X = volume/capacity, uniform delay d = 0.5*C*(1-lam)^2/(1 - min(1,X)*lam) rounded half up to tenths. LOS thresholds on tenths: <=100 A, <=200 B, <=350 C, <=550 D, <=800 E, else F; any X > 1 is F. Return {vc_milli: floor(1000X), delay_tenths, los}.

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):
    C, g = x['cycle'], x['green']
    lam = Fraction(g, C)
    cap = x['sat_per_lane'] * x['lanes'] * lam
    X = Fraction(x['volume']) / cap
    d = Fraction(1, 2) * C * (1 - lam) ** 2 / (1 - min(1, X) * lam)
    tenths = int(d * 10 + Fraction(1, 2))
    if X >= 1:
        los = 'F'
    else:
        los = 'F'
        for lim, lab in ((100, 'A'), (200, 'B'), (350, 'C'), (550, 'D'), (800, 'E')):
            if tenths <= lim:
                los = lab
                break
    return {'vc_milli': int(X * 1000), 'delay_tenths': tenths, 'los': los}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[({'cycle': 100, 'green': 12, 'volume': 215, 'sat_per_lane': 1800, 'lanes': 2}, {'vc_milli': 497, 'delay_tenths': 412, 'los': 'D'}), ({'cycle': 150, 'green': 120, 'volume': 2720, 'sat_per_lane': 1700, 'lanes': 2}, {'vc_milli': 1000, 'delay_tenths': 150, 'los': 'B'}), ({'cycle': 130, 'green': 65, 'volume': 1900, 'sat_per_lane': 1900, 'lanes': 2}, {'vc_milli': 1000, 'delay_tenths': 325, 'los': 'C'}), ({'cycle': 60, 'green': 36, 'volume': 2389, 'sat_per_lane': 1900, 'lanes': 2}, {'vc_milli': 1047, 'delay_tenths': 120, 'los': 'F'}), ({'cycle': 120, 'green': 40, 'volume': 1300, 'sat_per_lane': 1900, 'lanes': 2}, {'vc_milli': 1026, 'delay_tenths': 400, 'los': 'F'}), ({'cycle': 100, 'green': 50, 'volume': 900, 'sat_per_lane': 1800, 'lanes': 1}, {'vc_milli': 1000, 'delay_tenths': 250, 'los': 'C'}), ({'cycle': 90, 'green': 30, 'volume': 700, 'sat_per_lane': 1800, 'lanes': 2}, {'vc_milli': 583, 'delay_tenths': 248, 'los': 'C'}), ({'cycle': 140, 'green': 78, 'volume': 3819, 'sat_per_lane': 1900, 'lanes': 3}, {'vc_milli': 1202, 'delay_tenths': 310, 'los': 'F'})], [({'cycle': 120, 'green': 40, 'volume': 1300, 'sat_per_lane': 1900, 'lanes': 2}, {'vc_milli': 1026, 'delay_tenths': 400, 'los': 'F'}), ({'cycle': 100, 'green': 50, 'volume': 900, 'sat_per_lane': 1800, 'lanes': 1}, {'vc_milli': 1000, 'delay_tenths': 250, 'los': 'C'}), ({'cycle': 110, 'green': 94, 'volume': 1438, 'sat_per_lane': 1900, 'lanes': 1}, {'vc_milli': 885, 'delay_tenths': 48, 'los': 'A'}), ({'cycle': 150, 'green': 93, 'volume': 3162, 'sat_per_lane': 1700, 'lanes': 3}, {'vc_milli': 1000, 'delay_tenths': 285, 'los': 'C'}), ({'cycle': 110, 'green': 55, 'volume': 2088, 'sat_per_lane': 1900, 'lanes': 2}, {'vc_milli': 1098, 'delay_tenths': 275, 'los': 'F'}), ({'cycle': 70, 'green': 44, 'volume': 6920, 'sat_per_lane': 1900, 'lanes': 3}, {'vc_milli': 1931, 'delay_tenths': 130, 'los': 'F'}), ({'cycle': 120, 'green': 76, 'volume': 3230, 'sat_per_lane': 1700, 'lanes': 3}, {'vc_milli': 1000, 'delay_tenths': 220, 'los': 'C'}), ({'cycle': 100, 'green': 50, 'volume': 675, 'sat_per_lane': 1800, 'lanes': 1}, {'vc_milli': 750, 'delay_tenths': 200, 'los': 'B'})], [({'cycle': 60, 'green': 40, 'volume': 800, 'sat_per_lane': 1800, 'lanes': 1}, {'vc_milli': 666, 'delay_tenths': 60, 'los': 'A'}), ({'cycle': 120, 'green': 96, 'volume': 1520, 'sat_per_lane': 1900, 'lanes': 1}, {'vc_milli': 1000, 'delay_tenths': 120, 'los': 'B'}), ({'cycle': 100, 'green': 50, 'volume': 675, 'sat_per_lane': 1800, 'lanes': 1}, {'vc_milli': 750, 'delay_tenths': 200, 'los': 'B'}), ({'cycle': 90, 'green': 30, 'volume': 700, 'sat_per_lane': 1800, 'lanes': 2}, {'vc_milli': 583, 'delay_tenths': 248, 'los': 'C'}), ({'cycle': 150, 'green': 24, 'volume': 868, 'sat_per_lane': 1800, 'lanes': 3}, {'vc_milli': 1004, 'delay_tenths': 630, 'los': 'F'}), ({'cycle': 120, 'green': 45, 'volume': 1425, 'sat_per_lane': 1900, 'lanes': 2}, {'vc_milli': 1000, 'delay_tenths': 375, 'los': 'D'}), ({'cycle': 100, 'green': 20, 'volume': 1080, 'sat_per_lane': 1800, 'lanes': 3}, {'vc_milli': 1000, 'delay_tenths': 400, 'los': 'D'}), ({'cycle': 140, 'green': 57, 'volume': 804, 'sat_per_lane': 1900, 'lanes': 1}, {'vc_milli': 1039, 'delay_tenths': 415, 'los': 'F'})], [({'cycle': 60, 'green': 40, 'volume': 800, 'sat_per_lane': 1800, 'lanes': 1}, {'vc_milli': 666, 'delay_tenths': 60, 'los': 'A'}), ({'cycle': 140, 'green': 56, 'volume': 1477, 'sat_per_lane': 1700, 'lanes': 2}, {'vc_milli': 1086, 'delay_tenths': 420, 'los': 'F'}), ({'cycle': 120, 'green': 40, 'volume': 1300, 'sat_per_lane': 1900, 'lanes': 2}, {'vc_milli': 1026, 'delay_tenths': 400, 'los': 'F'}), ({'cycle': 100, 'green': 46, 'volume': 1656, 'sat_per_lane': 1800, 'lanes': 2}, {'vc_milli': 1000, 'delay_tenths': 270, 'los': 'C'}), ({'cycle': 90, 'green': 59, 'volume': 2360, 'sat_per_lane': 1800, 'lanes': 2}, {'vc_milli': 1000, 'delay_tenths': 155, 'los': 'B'}), ({'cycle': 130, 'green': 28, 'volume': 1476, 'sat_per_lane': 1700, 'lanes': 3}, {'vc_milli': 1343, 'delay_tenths': 510, 'los': 'F'}), ({'cycle': 100, 'green': 50, 'volume': 675, 'sat_per_lane': 1800, 'lanes': 1}, {'vc_milli': 750, 'delay_tenths': 200, 'los': 'B'}), ({'cycle': 150, 'green': 119, 'volume': 2856, 'sat_per_lane': 1800, 'lanes': 2}, {'vc_milli': 1000, 'delay_tenths': 155, 'los': 'B'})], [({'cycle': 60, 'green': 40, 'volume': 800, 'sat_per_lane': 1800, 'lanes': 1}, {'vc_milli': 666, 'delay_tenths': 60, 'los': 'A'}), ({'cycle': 140, 'green': 115, 'volume': 3804, 'sat_per_lane': 1700, 'lanes': 2}, {'vc_milli': 1362, 'delay_tenths': 125, 'los': 'F'}), ({'cycle': 150, 'green': 77, 'volume': 949, 'sat_per_lane': 1700, 'lanes': 1}, {'vc_milli': 1087, 'delay_tenths': 365, 'los': 'F'}), ({'cycle': 70, 'green': 34, 'volume': 1656, 'sat_per_lane': 1700, 'lanes': 2}, {'vc_milli': 1002, 'delay_tenths': 180, 'los': 'F'}), ({'cycle': 90, 'green': 30, 'volume': 700, 'sat_per_lane': 1800, 'lanes': 2}, {'vc_milli': 583, 'delay_tenths': 248, 'los': 'C'}), ({'cycle': 80, 'green': 20, 'volume': 1275, 'sat_per_lane': 1700, 'lanes': 3}, {'vc_milli': 1000, 'delay_tenths': 300, 'los': 'C'}), ({'cycle': 100, 'green': 75, 'volume': 1275, 'sat_per_lane': 1700, 'lanes': 1}, {'vc_milli': 1000, 'delay_tenths': 125, 'los': 'B'}), ({'cycle': 100, 'green': 50, 'volume': 900, 'sat_per_lane': 1800, 'lanes': 1}, {'vc_milli': 1000, 'delay_tenths': 250, 'los': 'C'})]]
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{'delay_tenths': 412, 'los': 'D', 'vc_milli': 497}{'delay_tenths': 412, 'los': 'D', 'vc_milli': 497}Passed
timing oracle 1{'delay_tenths': 150, 'los': 'F', 'vc_milli': 1000}{'delay_tenths': 150, 'los': 'B', 'vc_milli': 1000}Failed
timing oracle 2{'delay_tenths': 325, 'los': 'F', 'vc_milli': 1000}{'delay_tenths': 325, 'los': 'C', 'vc_milli': 1000}Failed
timing oracle 3{'delay_tenths': 120, 'los': 'F', 'vc_milli': 1047}{'delay_tenths': 120, 'los': 'F', 'vc_milli': 1047}Passed
timing oracle 4{'delay_tenths': 400, 'los': 'F', 'vc_milli': 1026}{'delay_tenths': 400, 'los': 'F', 'vc_milli': 1026}Passed
timing oracle 5{'delay_tenths': 250, 'los': 'F', 'vc_milli': 1000}{'delay_tenths': 250, 'los': 'C', 'vc_milli': 1000}Failed
timing oracle 6{'delay_tenths': 248, 'los': 'C', 'vc_milli': 583}{'delay_tenths': 248, 'los': 'C', 'vc_milli': 583}Passed
timing oracle 7{'delay_tenths': 310, 'los': 'F', 'vc_milli': 1202}{'delay_tenths': 310, 'los': 'F', 'vc_milli': 1202}Passed

SHA-256 / 4634784c3904a4e4139f77a8ea22632926133b7d8de6afb9c3ff109d6653b37b

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):
    C, g = x['cycle'], x['green']
    lam = Fraction(g, C)
    cap = x['sat_per_lane'] * x['lanes'] * lam
    X = Fraction(x['volume']) / cap
    d = Fraction(1, 2) * C * (1 - lam) ** 2 / (1 - min(1, X) * lam)
    tenths = int(d * 10 + Fraction(1, 2))
    if X > Fraction(11, 10):
        los = 'F'
    else:
        los = 'F'
        for lim, lab in ((100, 'A'), (200, 'B'), (350, 'C'), (550, 'D'), (800, 'E')):
            if tenths <= lim:
                los = lab
                break
    return {'vc_milli': int(X * 1000), 'delay_tenths': tenths, 'los': los}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[({'cycle': 100, 'green': 12, 'volume': 215, 'sat_per_lane': 1800, 'lanes': 2}, {'vc_milli': 497, 'delay_tenths': 412, 'los': 'D'}), ({'cycle': 150, 'green': 120, 'volume': 2720, 'sat_per_lane': 1700, 'lanes': 2}, {'vc_milli': 1000, 'delay_tenths': 150, 'los': 'B'}), ({'cycle': 130, 'green': 65, 'volume': 1900, 'sat_per_lane': 1900, 'lanes': 2}, {'vc_milli': 1000, 'delay_tenths': 325, 'los': 'C'}), ({'cycle': 60, 'green': 36, 'volume': 2389, 'sat_per_lane': 1900, 'lanes': 2}, {'vc_milli': 1047, 'delay_tenths': 120, 'los': 'F'}), ({'cycle': 120, 'green': 40, 'volume': 1300, 'sat_per_lane': 1900, 'lanes': 2}, {'vc_milli': 1026, 'delay_tenths': 400, 'los': 'F'}), ({'cycle': 100, 'green': 50, 'volume': 900, 'sat_per_lane': 1800, 'lanes': 1}, {'vc_milli': 1000, 'delay_tenths': 250, 'los': 'C'}), ({'cycle': 90, 'green': 30, 'volume': 700, 'sat_per_lane': 1800, 'lanes': 2}, {'vc_milli': 583, 'delay_tenths': 248, 'los': 'C'}), ({'cycle': 140, 'green': 78, 'volume': 3819, 'sat_per_lane': 1900, 'lanes': 3}, {'vc_milli': 1202, 'delay_tenths': 310, 'los': 'F'})], [({'cycle': 120, 'green': 40, 'volume': 1300, 'sat_per_lane': 1900, 'lanes': 2}, {'vc_milli': 1026, 'delay_tenths': 400, 'los': 'F'}), ({'cycle': 100, 'green': 50, 'volume': 900, 'sat_per_lane': 1800, 'lanes': 1}, {'vc_milli': 1000, 'delay_tenths': 250, 'los': 'C'}), ({'cycle': 110, 'green': 94, 'volume': 1438, 'sat_per_lane': 1900, 'lanes': 1}, {'vc_milli': 885, 'delay_tenths': 48, 'los': 'A'}), ({'cycle': 150, 'green': 93, 'volume': 3162, 'sat_per_lane': 1700, 'lanes': 3}, {'vc_milli': 1000, 'delay_tenths': 285, 'los': 'C'}), ({'cycle': 110, 'green': 55, 'volume': 2088, 'sat_per_lane': 1900, 'lanes': 2}, {'vc_milli': 1098, 'delay_tenths': 275, 'los': 'F'}), ({'cycle': 70, 'green': 44, 'volume': 6920, 'sat_per_lane': 1900, 'lanes': 3}, {'vc_milli': 1931, 'delay_tenths': 130, 'los': 'F'}), ({'cycle': 120, 'green': 76, 'volume': 3230, 'sat_per_lane': 1700, 'lanes': 3}, {'vc_milli': 1000, 'delay_tenths': 220, 'los': 'C'}), ({'cycle': 100, 'green': 50, 'volume': 675, 'sat_per_lane': 1800, 'lanes': 1}, {'vc_milli': 750, 'delay_tenths': 200, 'los': 'B'})], [({'cycle': 60, 'green': 40, 'volume': 800, 'sat_per_lane': 1800, 'lanes': 1}, {'vc_milli': 666, 'delay_tenths': 60, 'los': 'A'}), ({'cycle': 120, 'green': 96, 'volume': 1520, 'sat_per_lane': 1900, 'lanes': 1}, {'vc_milli': 1000, 'delay_tenths': 120, 'los': 'B'}), ({'cycle': 100, 'green': 50, 'volume': 675, 'sat_per_lane': 1800, 'lanes': 1}, {'vc_milli': 750, 'delay_tenths': 200, 'los': 'B'}), ({'cycle': 90, 'green': 30, 'volume': 700, 'sat_per_lane': 1800, 'lanes': 2}, {'vc_milli': 583, 'delay_tenths': 248, 'los': 'C'}), ({'cycle': 150, 'green': 24, 'volume': 868, 'sat_per_lane': 1800, 'lanes': 3}, {'vc_milli': 1004, 'delay_tenths': 630, 'los': 'F'}), ({'cycle': 120, 'green': 45, 'volume': 1425, 'sat_per_lane': 1900, 'lanes': 2}, {'vc_milli': 1000, 'delay_tenths': 375, 'los': 'D'}), ({'cycle': 100, 'green': 20, 'volume': 1080, 'sat_per_lane': 1800, 'lanes': 3}, {'vc_milli': 1000, 'delay_tenths': 400, 'los': 'D'}), ({'cycle': 140, 'green': 57, 'volume': 804, 'sat_per_lane': 1900, 'lanes': 1}, {'vc_milli': 1039, 'delay_tenths': 415, 'los': 'F'})], [({'cycle': 60, 'green': 40, 'volume': 800, 'sat_per_lane': 1800, 'lanes': 1}, {'vc_milli': 666, 'delay_tenths': 60, 'los': 'A'}), ({'cycle': 140, 'green': 56, 'volume': 1477, 'sat_per_lane': 1700, 'lanes': 2}, {'vc_milli': 1086, 'delay_tenths': 420, 'los': 'F'}), ({'cycle': 120, 'green': 40, 'volume': 1300, 'sat_per_lane': 1900, 'lanes': 2}, {'vc_milli': 1026, 'delay_tenths': 400, 'los': 'F'}), ({'cycle': 100, 'green': 46, 'volume': 1656, 'sat_per_lane': 1800, 'lanes': 2}, {'vc_milli': 1000, 'delay_tenths': 270, 'los': 'C'}), ({'cycle': 90, 'green': 59, 'volume': 2360, 'sat_per_lane': 1800, 'lanes': 2}, {'vc_milli': 1000, 'delay_tenths': 155, 'los': 'B'}), ({'cycle': 130, 'green': 28, 'volume': 1476, 'sat_per_lane': 1700, 'lanes': 3}, {'vc_milli': 1343, 'delay_tenths': 510, 'los': 'F'}), ({'cycle': 100, 'green': 50, 'volume': 675, 'sat_per_lane': 1800, 'lanes': 1}, {'vc_milli': 750, 'delay_tenths': 200, 'los': 'B'}), ({'cycle': 150, 'green': 119, 'volume': 2856, 'sat_per_lane': 1800, 'lanes': 2}, {'vc_milli': 1000, 'delay_tenths': 155, 'los': 'B'})], [({'cycle': 60, 'green': 40, 'volume': 800, 'sat_per_lane': 1800, 'lanes': 1}, {'vc_milli': 666, 'delay_tenths': 60, 'los': 'A'}), ({'cycle': 140, 'green': 115, 'volume': 3804, 'sat_per_lane': 1700, 'lanes': 2}, {'vc_milli': 1362, 'delay_tenths': 125, 'los': 'F'}), ({'cycle': 150, 'green': 77, 'volume': 949, 'sat_per_lane': 1700, 'lanes': 1}, {'vc_milli': 1087, 'delay_tenths': 365, 'los': 'F'}), ({'cycle': 70, 'green': 34, 'volume': 1656, 'sat_per_lane': 1700, 'lanes': 2}, {'vc_milli': 1002, 'delay_tenths': 180, 'los': 'F'}), ({'cycle': 90, 'green': 30, 'volume': 700, 'sat_per_lane': 1800, 'lanes': 2}, {'vc_milli': 583, 'delay_tenths': 248, 'los': 'C'}), ({'cycle': 80, 'green': 20, 'volume': 1275, 'sat_per_lane': 1700, 'lanes': 3}, {'vc_milli': 1000, 'delay_tenths': 300, 'los': 'C'}), ({'cycle': 100, 'green': 75, 'volume': 1275, 'sat_per_lane': 1700, 'lanes': 1}, {'vc_milli': 1000, 'delay_tenths': 125, 'los': 'B'}), ({'cycle': 100, 'green': 50, 'volume': 900, 'sat_per_lane': 1800, 'lanes': 1}, {'vc_milli': 1000, 'delay_tenths': 250, 'los': 'C'})]]
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{'delay_tenths': 412, 'los': 'D', 'vc_milli': 497}{'delay_tenths': 412, 'los': 'D', 'vc_milli': 497}Passed
timing oracle 1{'delay_tenths': 150, 'los': 'B', 'vc_milli': 1000}{'delay_tenths': 150, 'los': 'B', 'vc_milli': 1000}Passed
timing oracle 2{'delay_tenths': 325, 'los': 'C', 'vc_milli': 1000}{'delay_tenths': 325, 'los': 'C', 'vc_milli': 1000}Passed
timing oracle 3{'delay_tenths': 120, 'los': 'B', 'vc_milli': 1047}{'delay_tenths': 120, 'los': 'F', 'vc_milli': 1047}Failed
timing oracle 4{'delay_tenths': 400, 'los': 'D', 'vc_milli': 1026}{'delay_tenths': 400, 'los': 'F', 'vc_milli': 1026}Failed
timing oracle 5{'delay_tenths': 250, 'los': 'C', 'vc_milli': 1000}{'delay_tenths': 250, 'los': 'C', 'vc_milli': 1000}Passed
timing oracle 6{'delay_tenths': 248, 'los': 'C', 'vc_milli': 583}{'delay_tenths': 248, 'los': 'C', 'vc_milli': 583}Passed
timing oracle 7{'delay_tenths': 310, 'los': 'F', 'vc_milli': 1202}{'delay_tenths': 310, 'los': 'F', 'vc_milli': 1202}Passed

SHA-256 / fd1e788b98db2f79055ebe3b47b9c62783d2a8aa81e1ae6c3333693a09384d4b

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):
    C, g = x['cycle'], x['green']
    lam = Fraction(g, C)
    cap = x['sat_per_lane'] * x['lanes'] * lam
    X = Fraction(x['volume']) / cap
    d = Fraction(1, 2) * C * (1 - lam) ** 2 / (1 - min(1, X) * lam)
    tenths = int(d * 10 + Fraction(1, 2))
    if X > 1:
        los = 'F'
    else:
        los = 'F'
        for lim, lab in ((100, 'A'), (200, 'B'), (350, 'C'), (550, 'D'), (800, 'E')):
            if tenths <= lim:
                los = lab
                break
    return {'vc_milli': int(X * 1000), 'delay_tenths': tenths, 'los': los}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[({'cycle': 100, 'green': 12, 'volume': 215, 'sat_per_lane': 1800, 'lanes': 2}, {'vc_milli': 497, 'delay_tenths': 412, 'los': 'D'}), ({'cycle': 150, 'green': 120, 'volume': 2720, 'sat_per_lane': 1700, 'lanes': 2}, {'vc_milli': 1000, 'delay_tenths': 150, 'los': 'B'}), ({'cycle': 130, 'green': 65, 'volume': 1900, 'sat_per_lane': 1900, 'lanes': 2}, {'vc_milli': 1000, 'delay_tenths': 325, 'los': 'C'}), ({'cycle': 60, 'green': 36, 'volume': 2389, 'sat_per_lane': 1900, 'lanes': 2}, {'vc_milli': 1047, 'delay_tenths': 120, 'los': 'F'}), ({'cycle': 120, 'green': 40, 'volume': 1300, 'sat_per_lane': 1900, 'lanes': 2}, {'vc_milli': 1026, 'delay_tenths': 400, 'los': 'F'}), ({'cycle': 100, 'green': 50, 'volume': 900, 'sat_per_lane': 1800, 'lanes': 1}, {'vc_milli': 1000, 'delay_tenths': 250, 'los': 'C'}), ({'cycle': 90, 'green': 30, 'volume': 700, 'sat_per_lane': 1800, 'lanes': 2}, {'vc_milli': 583, 'delay_tenths': 248, 'los': 'C'}), ({'cycle': 140, 'green': 78, 'volume': 3819, 'sat_per_lane': 1900, 'lanes': 3}, {'vc_milli': 1202, 'delay_tenths': 310, 'los': 'F'})], [({'cycle': 120, 'green': 40, 'volume': 1300, 'sat_per_lane': 1900, 'lanes': 2}, {'vc_milli': 1026, 'delay_tenths': 400, 'los': 'F'}), ({'cycle': 100, 'green': 50, 'volume': 900, 'sat_per_lane': 1800, 'lanes': 1}, {'vc_milli': 1000, 'delay_tenths': 250, 'los': 'C'}), ({'cycle': 110, 'green': 94, 'volume': 1438, 'sat_per_lane': 1900, 'lanes': 1}, {'vc_milli': 885, 'delay_tenths': 48, 'los': 'A'}), ({'cycle': 150, 'green': 93, 'volume': 3162, 'sat_per_lane': 1700, 'lanes': 3}, {'vc_milli': 1000, 'delay_tenths': 285, 'los': 'C'}), ({'cycle': 110, 'green': 55, 'volume': 2088, 'sat_per_lane': 1900, 'lanes': 2}, {'vc_milli': 1098, 'delay_tenths': 275, 'los': 'F'}), ({'cycle': 70, 'green': 44, 'volume': 6920, 'sat_per_lane': 1900, 'lanes': 3}, {'vc_milli': 1931, 'delay_tenths': 130, 'los': 'F'}), ({'cycle': 120, 'green': 76, 'volume': 3230, 'sat_per_lane': 1700, 'lanes': 3}, {'vc_milli': 1000, 'delay_tenths': 220, 'los': 'C'}), ({'cycle': 100, 'green': 50, 'volume': 675, 'sat_per_lane': 1800, 'lanes': 1}, {'vc_milli': 750, 'delay_tenths': 200, 'los': 'B'})], [({'cycle': 60, 'green': 40, 'volume': 800, 'sat_per_lane': 1800, 'lanes': 1}, {'vc_milli': 666, 'delay_tenths': 60, 'los': 'A'}), ({'cycle': 120, 'green': 96, 'volume': 1520, 'sat_per_lane': 1900, 'lanes': 1}, {'vc_milli': 1000, 'delay_tenths': 120, 'los': 'B'}), ({'cycle': 100, 'green': 50, 'volume': 675, 'sat_per_lane': 1800, 'lanes': 1}, {'vc_milli': 750, 'delay_tenths': 200, 'los': 'B'}), ({'cycle': 90, 'green': 30, 'volume': 700, 'sat_per_lane': 1800, 'lanes': 2}, {'vc_milli': 583, 'delay_tenths': 248, 'los': 'C'}), ({'cycle': 150, 'green': 24, 'volume': 868, 'sat_per_lane': 1800, 'lanes': 3}, {'vc_milli': 1004, 'delay_tenths': 630, 'los': 'F'}), ({'cycle': 120, 'green': 45, 'volume': 1425, 'sat_per_lane': 1900, 'lanes': 2}, {'vc_milli': 1000, 'delay_tenths': 375, 'los': 'D'}), ({'cycle': 100, 'green': 20, 'volume': 1080, 'sat_per_lane': 1800, 'lanes': 3}, {'vc_milli': 1000, 'delay_tenths': 400, 'los': 'D'}), ({'cycle': 140, 'green': 57, 'volume': 804, 'sat_per_lane': 1900, 'lanes': 1}, {'vc_milli': 1039, 'delay_tenths': 415, 'los': 'F'})], [({'cycle': 60, 'green': 40, 'volume': 800, 'sat_per_lane': 1800, 'lanes': 1}, {'vc_milli': 666, 'delay_tenths': 60, 'los': 'A'}), ({'cycle': 140, 'green': 56, 'volume': 1477, 'sat_per_lane': 1700, 'lanes': 2}, {'vc_milli': 1086, 'delay_tenths': 420, 'los': 'F'}), ({'cycle': 120, 'green': 40, 'volume': 1300, 'sat_per_lane': 1900, 'lanes': 2}, {'vc_milli': 1026, 'delay_tenths': 400, 'los': 'F'}), ({'cycle': 100, 'green': 46, 'volume': 1656, 'sat_per_lane': 1800, 'lanes': 2}, {'vc_milli': 1000, 'delay_tenths': 270, 'los': 'C'}), ({'cycle': 90, 'green': 59, 'volume': 2360, 'sat_per_lane': 1800, 'lanes': 2}, {'vc_milli': 1000, 'delay_tenths': 155, 'los': 'B'}), ({'cycle': 130, 'green': 28, 'volume': 1476, 'sat_per_lane': 1700, 'lanes': 3}, {'vc_milli': 1343, 'delay_tenths': 510, 'los': 'F'}), ({'cycle': 100, 'green': 50, 'volume': 675, 'sat_per_lane': 1800, 'lanes': 1}, {'vc_milli': 750, 'delay_tenths': 200, 'los': 'B'}), ({'cycle': 150, 'green': 119, 'volume': 2856, 'sat_per_lane': 1800, 'lanes': 2}, {'vc_milli': 1000, 'delay_tenths': 155, 'los': 'B'})], [({'cycle': 60, 'green': 40, 'volume': 800, 'sat_per_lane': 1800, 'lanes': 1}, {'vc_milli': 666, 'delay_tenths': 60, 'los': 'A'}), ({'cycle': 140, 'green': 115, 'volume': 3804, 'sat_per_lane': 1700, 'lanes': 2}, {'vc_milli': 1362, 'delay_tenths': 125, 'los': 'F'}), ({'cycle': 150, 'green': 77, 'volume': 949, 'sat_per_lane': 1700, 'lanes': 1}, {'vc_milli': 1087, 'delay_tenths': 365, 'los': 'F'}), ({'cycle': 70, 'green': 34, 'volume': 1656, 'sat_per_lane': 1700, 'lanes': 2}, {'vc_milli': 1002, 'delay_tenths': 180, 'los': 'F'}), ({'cycle': 90, 'green': 30, 'volume': 700, 'sat_per_lane': 1800, 'lanes': 2}, {'vc_milli': 583, 'delay_tenths': 248, 'los': 'C'}), ({'cycle': 80, 'green': 20, 'volume': 1275, 'sat_per_lane': 1700, 'lanes': 3}, {'vc_milli': 1000, 'delay_tenths': 300, 'los': 'C'}), ({'cycle': 100, 'green': 75, 'volume': 1275, 'sat_per_lane': 1700, 'lanes': 1}, {'vc_milli': 1000, 'delay_tenths': 125, 'los': 'B'}), ({'cycle': 100, 'green': 50, 'volume': 900, 'sat_per_lane': 1800, 'lanes': 1}, {'vc_milli': 1000, 'delay_tenths': 250, 'los': 'C'})]]
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{'delay_tenths': 412, 'los': 'D', 'vc_milli': 497}{'delay_tenths': 412, 'los': 'D', 'vc_milli': 497}Passed
timing oracle 1{'delay_tenths': 150, 'los': 'B', 'vc_milli': 1000}{'delay_tenths': 150, 'los': 'B', 'vc_milli': 1000}Passed
timing oracle 2{'delay_tenths': 325, 'los': 'C', 'vc_milli': 1000}{'delay_tenths': 325, 'los': 'C', 'vc_milli': 1000}Passed
timing oracle 3{'delay_tenths': 120, 'los': 'F', 'vc_milli': 1047}{'delay_tenths': 120, 'los': 'F', 'vc_milli': 1047}Passed
timing oracle 4{'delay_tenths': 400, 'los': 'F', 'vc_milli': 1026}{'delay_tenths': 400, 'los': 'F', 'vc_milli': 1026}Passed
timing oracle 5{'delay_tenths': 250, 'los': 'C', 'vc_milli': 1000}{'delay_tenths': 250, 'los': 'C', 'vc_milli': 1000}Passed
timing oracle 6{'delay_tenths': 248, 'los': 'C', 'vc_milli': 583}{'delay_tenths': 248, 'los': 'C', 'vc_milli': 583}Passed
timing oracle 7{'delay_tenths': 310, 'los': 'F', 'vc_milli': 1202}{'delay_tenths': 310, 'los': 'F', 'vc_milli': 1202}Passed

SHA-256 / b200900eb6ef39c36209b90c2af3fe53251edc9968cd6694d0a8be293baa7993

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 2026-09-29T14:47:59.588063+00:00.

Case digest / 2361d772e4b291af30b9b599b54c67e97d800b96de596cb93b0457e6805c831c