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FA-67936 / Traffic signal timing plans / Open access

Pedestrian walk and clearance timing: the flashing dont walk interval is truncated · case 01

Pedestrian walk and clearance timing returns a wrong result when the flashing dont walk interval is truncated.

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

ROOT CAUSE

Floor division gives pedestrians less clearance than the crossing needs at the design walking speed.

THE FAILURE

Floor division gives pedestrians less clearance than the crossing needs at the design walking speed.

Unsuccessful approach: Ceiling division without the tenths scaling divides feet by a speed that is ten times too large.

Case contract

Input {crossing_ft, walk_speed_tenths (ft/s*10), min_walk, yellow_tenths, red_tenths, min_green, ped_call, split}. FDW = ceil(crossing*10/speed). Walk starts at min_walk and is extended so that walk + FDW >= ceil((crossing + 6)/3.0) (pushbutton-to-far-curb check at 3.0 ft/s). FDW may overlap yellow and all-red, so with a ped call the vehicle green is max(min_green, ceil(walk + FDW - (yellow+red))). Without a call green = min_green. fits is green + yellow + red <= split. Return {walk, fdw, green, fits}.

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):
    sp = x['walk_speed_tenths']
    fdw = x['crossing_ft'] * 10 // sp
    walk = x['min_walk']
    total = -(-(x['crossing_ft'] + 6) * 10 // 30)
    if walk + fdw < total:
        walk = total - fdw
    yr = Fraction(x['yellow_tenths'] + x['red_tenths'], 10)
    g = x['min_green']
    if x['ped_call']:
        need = walk + fdw - yr
        g = max(g, math.ceil(need))
    return {'walk': walk, 'fdw': fdw, 'green': g, 'fits': g + yr <= x['split']}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[({'crossing_ft': 36, 'walk_speed_tenths': 40, 'min_walk': 7, 'yellow_tenths': 30, 'red_tenths': 10, 'min_green': 8, 'ped_call': False, 'split': 12}, {'walk': 7, 'fdw': 9, 'green': 8, 'fits': True}), ({'crossing_ft': 70, 'walk_speed_tenths': 35, 'min_walk': 7, 'yellow_tenths': 40, 'red_tenths': 20, 'min_green': 5, 'ped_call': True, 'split': 30}, {'walk': 7, 'fdw': 20, 'green': 21, 'fits': True}), ({'crossing_ft': 90, 'walk_speed_tenths': 35, 'min_walk': 4, 'yellow_tenths': 35, 'red_tenths': 15, 'min_green': 10, 'ped_call': True, 'split': 35}, {'walk': 6, 'fdw': 26, 'green': 27, 'fits': True}), ({'crossing_ft': 27, 'walk_speed_tenths': 30, 'min_walk': 5, 'yellow_tenths': 45, 'red_tenths': 15, 'min_green': 10, 'ped_call': True, 'split': 38}, {'walk': 5, 'fdw': 9, 'green': 10, 'fits': True}), ({'crossing_ft': 110, 'walk_speed_tenths': 35, 'min_walk': 5, 'yellow_tenths': 30, 'red_tenths': 20, 'min_green': 5, 'ped_call': True, 'split': 40}, {'walk': 7, 'fdw': 32, 'green': 34, 'fits': True}), ({'crossing_ft': 42, 'walk_speed_tenths': 40, 'min_walk': 4, 'yellow_tenths': 40, 'red_tenths': 10, 'min_green': 10, 'ped_call': True, 'split': 41}, {'walk': 5, 'fdw': 11, 'green': 11, 'fits': True}), ({'crossing_ft': 74, 'walk_speed_tenths': 30, 'min_walk': 7, 'yellow_tenths': 45, 'red_tenths': 10, 'min_green': 15, 'ped_call': True, 'split': 18}, {'walk': 7, 'fdw': 25, 'green': 27, 'fits': False}), ({'crossing_ft': 89, 'walk_speed_tenths': 35, 'min_walk': 10, 'yellow_tenths': 40, 'red_tenths': 15, 'min_green': 8, 'ped_call': False, 'split': 43}, {'walk': 10, 'fdw': 26, 'green': 8, 'fits': True})], [({'crossing_ft': 41, 'walk_speed_tenths': 40, 'min_walk': 7, 'yellow_tenths': 45, 'red_tenths': 15, 'min_green': 5, 'ped_call': True, 'split': 41}, {'walk': 7, 'fdw': 11, 'green': 12, 'fits': True}), ({'crossing_ft': 33, 'walk_speed_tenths': 35, 'min_walk': 7, 'yellow_tenths': 45, 'red_tenths': 10, 'min_green': 10, 'ped_call': True, 'split': 42}, {'walk': 7, 'fdw': 10, 'green': 12, 'fits': True}), ({'crossing_ft': 37, 'walk_speed_tenths': 35, 'min_walk': 7, 'yellow_tenths': 30, 'red_tenths': 20, 'min_green': 15, 'ped_call': False, 'split': 39}, {'walk': 7, 'fdw': 11, 'green': 15, 'fits': True}), ({'crossing_ft': 36, 'walk_speed_tenths': 35, 'min_walk': 10, 'yellow_tenths': 30, 'red_tenths': 20, 'min_green': 8, 'ped_call': True, 'split': 29}, {'walk': 10, 'fdw': 11, 'green': 16, 'fits': True}), ({'crossing_ft': 90, 'walk_speed_tenths': 35, 'min_walk': 4, 'yellow_tenths': 35, 'red_tenths': 15, 'min_green': 10, 'ped_call': True, 'split': 35}, {'walk': 6, 'fdw': 26, 'green': 27, 'fits': True}), ({'crossing_ft': 70, 'walk_speed_tenths': 35, 'min_walk': 7, 'yellow_tenths': 40, 'red_tenths': 20, 'min_green': 5, 'ped_call': True, 'split': 30}, {'walk': 7, 'fdw': 20, 'green': 21, 'fits': True}), ({'crossing_ft': 36, 'walk_speed_tenths': 40, 'min_walk': 7, 'yellow_tenths': 30, 'red_tenths': 10, 'min_green': 8, 'ped_call': False, 'split': 12}, {'walk': 7, 'fdw': 9, 'green': 8, 'fits': True}), ({'crossing_ft': 84, 'walk_speed_tenths': 35, 'min_walk': 10, 'yellow_tenths': 45, 'red_tenths': 15, 'min_green': 8, 'ped_call': True, 'split': 26}, {'walk': 10, 'fdw': 24, 'green': 28, 'fits': False})], [({'crossing_ft': 79, 'walk_speed_tenths': 35, 'min_walk': 7, 'yellow_tenths': 45, 'red_tenths': 10, 'min_green': 8, 'ped_call': False, 'split': 21}, {'walk': 7, 'fdw': 23, 'green': 8, 'fits': True}), ({'crossing_ft': 109, 'walk_speed_tenths': 35, 'min_walk': 4, 'yellow_tenths': 35, 'red_tenths': 20, 'min_green': 10, 'ped_call': False, 'split': 31}, {'walk': 7, 'fdw': 32, 'green': 10, 'fits': True}), ({'crossing_ft': 40, 'walk_speed_tenths': 35, 'min_walk': 4, 'yellow_tenths': 30, 'red_tenths': 10, 'min_green': 10, 'ped_call': True, 'split': 39}, {'walk': 4, 'fdw': 12, 'green': 12, 'fits': True}), ({'crossing_ft': 36, 'walk_speed_tenths': 40, 'min_walk': 7, 'yellow_tenths': 30, 'red_tenths': 10, 'min_green': 8, 'ped_call': False, 'split': 12}, {'walk': 7, 'fdw': 9, 'green': 8, 'fits': True}), ({'crossing_ft': 24, 'walk_speed_tenths': 35, 'min_walk': 10, 'yellow_tenths': 45, 'red_tenths': 10, 'min_green': 10, 'ped_call': True, 'split': 30}, {'walk': 10, 'fdw': 7, 'green': 12, 'fits': True}), ({'crossing_ft': 70, 'walk_speed_tenths': 35, 'min_walk': 7, 'yellow_tenths': 40, 'red_tenths': 20, 'min_green': 5, 'ped_call': True, 'split': 30}, {'walk': 7, 'fdw': 20, 'green': 21, 'fits': True}), ({'crossing_ft': 107, 'walk_speed_tenths': 30, 'min_walk': 10, 'yellow_tenths': 35, 'red_tenths': 20, 'min_green': 5, 'ped_call': True, 'split': 40}, {'walk': 10, 'fdw': 36, 'green': 41, 'fits': False}), ({'crossing_ft': 90, 'walk_speed_tenths': 35, 'min_walk': 4, 'yellow_tenths': 35, 'red_tenths': 15, 'min_green': 10, 'ped_call': True, 'split': 35}, {'walk': 6, 'fdw': 26, 'green': 27, 'fits': True})], [({'crossing_ft': 34, 'walk_speed_tenths': 35, 'min_walk': 7, 'yellow_tenths': 35, 'red_tenths': 10, 'min_green': 5, 'ped_call': True, 'split': 38}, {'walk': 7, 'fdw': 10, 'green': 13, 'fits': True}), ({'crossing_ft': 75, 'walk_speed_tenths': 30, 'min_walk': 5, 'yellow_tenths': 45, 'red_tenths': 10, 'min_green': 15, 'ped_call': True, 'split': 36}, {'walk': 5, 'fdw': 25, 'green': 25, 'fits': True}), ({'crossing_ft': 36, 'walk_speed_tenths': 40, 'min_walk': 7, 'yellow_tenths': 30, 'red_tenths': 10, 'min_green': 8, 'ped_call': False, 'split': 12}, {'walk': 7, 'fdw': 9, 'green': 8, 'fits': True}), ({'crossing_ft': 90, 'walk_speed_tenths': 35, 'min_walk': 4, 'yellow_tenths': 35, 'red_tenths': 15, 'min_green': 10, 'ped_call': True, 'split': 35}, {'walk': 6, 'fdw': 26, 'green': 27, 'fits': True}), ({'crossing_ft': 96, 'walk_speed_tenths': 35, 'min_walk': 5, 'yellow_tenths': 40, 'red_tenths': 10, 'min_green': 8, 'ped_call': False, 'split': 21}, {'walk': 6, 'fdw': 28, 'green': 8, 'fits': True}), ({'crossing_ft': 70, 'walk_speed_tenths': 35, 'min_walk': 7, 'yellow_tenths': 40, 'red_tenths': 20, 'min_green': 5, 'ped_call': True, 'split': 30}, {'walk': 7, 'fdw': 20, 'green': 21, 'fits': True}), ({'crossing_ft': 81, 'walk_speed_tenths': 35, 'min_walk': 10, 'yellow_tenths': 30, 'red_tenths': 10, 'min_green': 5, 'ped_call': True, 'split': 30}, {'walk': 10, 'fdw': 24, 'green': 30, 'fits': False}), ({'crossing_ft': 45, 'walk_speed_tenths': 35, 'min_walk': 7, 'yellow_tenths': 30, 'red_tenths': 20, 'min_green': 5, 'ped_call': False, 'split': 41}, {'walk': 7, 'fdw': 13, 'green': 5, 'fits': True})], [({'crossing_ft': 65, 'walk_speed_tenths': 35, 'min_walk': 5, 'yellow_tenths': 40, 'red_tenths': 10, 'min_green': 10, 'ped_call': True, 'split': 40}, {'walk': 5, 'fdw': 19, 'green': 19, 'fits': True}), ({'crossing_ft': 87, 'walk_speed_tenths': 35, 'min_walk': 10, 'yellow_tenths': 45, 'red_tenths': 10, 'min_green': 15, 'ped_call': True, 'split': 38}, {'walk': 10, 'fdw': 25, 'green': 30, 'fits': True}), ({'crossing_ft': 90, 'walk_speed_tenths': 35, 'min_walk': 4, 'yellow_tenths': 35, 'red_tenths': 15, 'min_green': 10, 'ped_call': True, 'split': 35}, {'walk': 6, 'fdw': 26, 'green': 27, 'fits': True}), ({'crossing_ft': 85, 'walk_speed_tenths': 30, 'min_walk': 5, 'yellow_tenths': 45, 'red_tenths': 15, 'min_green': 8, 'ped_call': True, 'split': 28}, {'walk': 5, 'fdw': 29, 'green': 28, 'fits': False}), ({'crossing_ft': 70, 'walk_speed_tenths': 35, 'min_walk': 7, 'yellow_tenths': 40, 'red_tenths': 20, 'min_green': 5, 'ped_call': True, 'split': 30}, {'walk': 7, 'fdw': 20, 'green': 21, 'fits': True}), ({'crossing_ft': 92, 'walk_speed_tenths': 35, 'min_walk': 7, 'yellow_tenths': 30, 'red_tenths': 20, 'min_green': 10, 'ped_call': True, 'split': 34}, {'walk': 7, 'fdw': 27, 'green': 29, 'fits': True}), ({'crossing_ft': 36, 'walk_speed_tenths': 40, 'min_walk': 7, 'yellow_tenths': 30, 'red_tenths': 10, 'min_green': 8, 'ped_call': False, 'split': 12}, {'walk': 7, 'fdw': 9, 'green': 8, 'fits': True}), ({'crossing_ft': 64, 'walk_speed_tenths': 30, 'min_walk': 4, 'yellow_tenths': 30, 'red_tenths': 20, 'min_green': 8, 'ped_call': True, 'split': 21}, {'walk': 4, 'fdw': 22, 'green': 21, 'fits': False})]]
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{'fdw': 9, 'fits': True, 'green': 8, 'walk': 7}{'fdw': 9, 'fits': True, 'green': 8, 'walk': 7}Passed
timing oracle 1{'fdw': 20, 'fits': True, 'green': 21, 'walk': 7}{'fdw': 20, 'fits': True, 'green': 21, 'walk': 7}Passed
timing oracle 2{'fdw': 25, 'fits': True, 'green': 27, 'walk': 7}{'fdw': 26, 'fits': True, 'green': 27, 'walk': 6}Failed
timing oracle 3{'fdw': 9, 'fits': True, 'green': 10, 'walk': 5}{'fdw': 9, 'fits': True, 'green': 10, 'walk': 5}Passed
timing oracle 4{'fdw': 31, 'fits': True, 'green': 34, 'walk': 8}{'fdw': 32, 'fits': True, 'green': 34, 'walk': 7}Failed
timing oracle 5{'fdw': 10, 'fits': True, 'green': 11, 'walk': 6}{'fdw': 11, 'fits': True, 'green': 11, 'walk': 5}Failed
timing oracle 6{'fdw': 24, 'fits': False, 'green': 26, 'walk': 7}{'fdw': 25, 'fits': False, 'green': 27, 'walk': 7}Failed
timing oracle 7{'fdw': 25, 'fits': True, 'green': 8, 'walk': 10}{'fdw': 26, 'fits': True, 'green': 8, 'walk': 10}Failed

SHA-256 / 54f89d4a38b1859e360e031ad02b889dc975a722ba3d2b92083d9de055e91b29

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):
    sp = x['walk_speed_tenths']
    fdw = -(-x['crossing_ft'] // sp)
    walk = x['min_walk']
    total = -(-(x['crossing_ft'] + 6) * 10 // 30)
    if walk + fdw < total:
        walk = total - fdw
    yr = Fraction(x['yellow_tenths'] + x['red_tenths'], 10)
    g = x['min_green']
    if x['ped_call']:
        need = walk + fdw - yr
        g = max(g, math.ceil(need))
    return {'walk': walk, 'fdw': fdw, 'green': g, 'fits': g + yr <= x['split']}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[({'crossing_ft': 36, 'walk_speed_tenths': 40, 'min_walk': 7, 'yellow_tenths': 30, 'red_tenths': 10, 'min_green': 8, 'ped_call': False, 'split': 12}, {'walk': 7, 'fdw': 9, 'green': 8, 'fits': True}), ({'crossing_ft': 70, 'walk_speed_tenths': 35, 'min_walk': 7, 'yellow_tenths': 40, 'red_tenths': 20, 'min_green': 5, 'ped_call': True, 'split': 30}, {'walk': 7, 'fdw': 20, 'green': 21, 'fits': True}), ({'crossing_ft': 90, 'walk_speed_tenths': 35, 'min_walk': 4, 'yellow_tenths': 35, 'red_tenths': 15, 'min_green': 10, 'ped_call': True, 'split': 35}, {'walk': 6, 'fdw': 26, 'green': 27, 'fits': True}), ({'crossing_ft': 27, 'walk_speed_tenths': 30, 'min_walk': 5, 'yellow_tenths': 45, 'red_tenths': 15, 'min_green': 10, 'ped_call': True, 'split': 38}, {'walk': 5, 'fdw': 9, 'green': 10, 'fits': True}), ({'crossing_ft': 110, 'walk_speed_tenths': 35, 'min_walk': 5, 'yellow_tenths': 30, 'red_tenths': 20, 'min_green': 5, 'ped_call': True, 'split': 40}, {'walk': 7, 'fdw': 32, 'green': 34, 'fits': True}), ({'crossing_ft': 42, 'walk_speed_tenths': 40, 'min_walk': 4, 'yellow_tenths': 40, 'red_tenths': 10, 'min_green': 10, 'ped_call': True, 'split': 41}, {'walk': 5, 'fdw': 11, 'green': 11, 'fits': True}), ({'crossing_ft': 74, 'walk_speed_tenths': 30, 'min_walk': 7, 'yellow_tenths': 45, 'red_tenths': 10, 'min_green': 15, 'ped_call': True, 'split': 18}, {'walk': 7, 'fdw': 25, 'green': 27, 'fits': False}), ({'crossing_ft': 89, 'walk_speed_tenths': 35, 'min_walk': 10, 'yellow_tenths': 40, 'red_tenths': 15, 'min_green': 8, 'ped_call': False, 'split': 43}, {'walk': 10, 'fdw': 26, 'green': 8, 'fits': True})], [({'crossing_ft': 41, 'walk_speed_tenths': 40, 'min_walk': 7, 'yellow_tenths': 45, 'red_tenths': 15, 'min_green': 5, 'ped_call': True, 'split': 41}, {'walk': 7, 'fdw': 11, 'green': 12, 'fits': True}), ({'crossing_ft': 33, 'walk_speed_tenths': 35, 'min_walk': 7, 'yellow_tenths': 45, 'red_tenths': 10, 'min_green': 10, 'ped_call': True, 'split': 42}, {'walk': 7, 'fdw': 10, 'green': 12, 'fits': True}), ({'crossing_ft': 37, 'walk_speed_tenths': 35, 'min_walk': 7, 'yellow_tenths': 30, 'red_tenths': 20, 'min_green': 15, 'ped_call': False, 'split': 39}, {'walk': 7, 'fdw': 11, 'green': 15, 'fits': True}), ({'crossing_ft': 36, 'walk_speed_tenths': 35, 'min_walk': 10, 'yellow_tenths': 30, 'red_tenths': 20, 'min_green': 8, 'ped_call': True, 'split': 29}, {'walk': 10, 'fdw': 11, 'green': 16, 'fits': True}), ({'crossing_ft': 90, 'walk_speed_tenths': 35, 'min_walk': 4, 'yellow_tenths': 35, 'red_tenths': 15, 'min_green': 10, 'ped_call': True, 'split': 35}, {'walk': 6, 'fdw': 26, 'green': 27, 'fits': True}), ({'crossing_ft': 70, 'walk_speed_tenths': 35, 'min_walk': 7, 'yellow_tenths': 40, 'red_tenths': 20, 'min_green': 5, 'ped_call': True, 'split': 30}, {'walk': 7, 'fdw': 20, 'green': 21, 'fits': True}), ({'crossing_ft': 36, 'walk_speed_tenths': 40, 'min_walk': 7, 'yellow_tenths': 30, 'red_tenths': 10, 'min_green': 8, 'ped_call': False, 'split': 12}, {'walk': 7, 'fdw': 9, 'green': 8, 'fits': True}), ({'crossing_ft': 84, 'walk_speed_tenths': 35, 'min_walk': 10, 'yellow_tenths': 45, 'red_tenths': 15, 'min_green': 8, 'ped_call': True, 'split': 26}, {'walk': 10, 'fdw': 24, 'green': 28, 'fits': False})], [({'crossing_ft': 79, 'walk_speed_tenths': 35, 'min_walk': 7, 'yellow_tenths': 45, 'red_tenths': 10, 'min_green': 8, 'ped_call': False, 'split': 21}, {'walk': 7, 'fdw': 23, 'green': 8, 'fits': True}), ({'crossing_ft': 109, 'walk_speed_tenths': 35, 'min_walk': 4, 'yellow_tenths': 35, 'red_tenths': 20, 'min_green': 10, 'ped_call': False, 'split': 31}, {'walk': 7, 'fdw': 32, 'green': 10, 'fits': True}), ({'crossing_ft': 40, 'walk_speed_tenths': 35, 'min_walk': 4, 'yellow_tenths': 30, 'red_tenths': 10, 'min_green': 10, 'ped_call': True, 'split': 39}, {'walk': 4, 'fdw': 12, 'green': 12, 'fits': True}), ({'crossing_ft': 36, 'walk_speed_tenths': 40, 'min_walk': 7, 'yellow_tenths': 30, 'red_tenths': 10, 'min_green': 8, 'ped_call': False, 'split': 12}, {'walk': 7, 'fdw': 9, 'green': 8, 'fits': True}), ({'crossing_ft': 24, 'walk_speed_tenths': 35, 'min_walk': 10, 'yellow_tenths': 45, 'red_tenths': 10, 'min_green': 10, 'ped_call': True, 'split': 30}, {'walk': 10, 'fdw': 7, 'green': 12, 'fits': True}), ({'crossing_ft': 70, 'walk_speed_tenths': 35, 'min_walk': 7, 'yellow_tenths': 40, 'red_tenths': 20, 'min_green': 5, 'ped_call': True, 'split': 30}, {'walk': 7, 'fdw': 20, 'green': 21, 'fits': True}), ({'crossing_ft': 107, 'walk_speed_tenths': 30, 'min_walk': 10, 'yellow_tenths': 35, 'red_tenths': 20, 'min_green': 5, 'ped_call': True, 'split': 40}, {'walk': 10, 'fdw': 36, 'green': 41, 'fits': False}), ({'crossing_ft': 90, 'walk_speed_tenths': 35, 'min_walk': 4, 'yellow_tenths': 35, 'red_tenths': 15, 'min_green': 10, 'ped_call': True, 'split': 35}, {'walk': 6, 'fdw': 26, 'green': 27, 'fits': True})], [({'crossing_ft': 34, 'walk_speed_tenths': 35, 'min_walk': 7, 'yellow_tenths': 35, 'red_tenths': 10, 'min_green': 5, 'ped_call': True, 'split': 38}, {'walk': 7, 'fdw': 10, 'green': 13, 'fits': True}), ({'crossing_ft': 75, 'walk_speed_tenths': 30, 'min_walk': 5, 'yellow_tenths': 45, 'red_tenths': 10, 'min_green': 15, 'ped_call': True, 'split': 36}, {'walk': 5, 'fdw': 25, 'green': 25, 'fits': True}), ({'crossing_ft': 36, 'walk_speed_tenths': 40, 'min_walk': 7, 'yellow_tenths': 30, 'red_tenths': 10, 'min_green': 8, 'ped_call': False, 'split': 12}, {'walk': 7, 'fdw': 9, 'green': 8, 'fits': True}), ({'crossing_ft': 90, 'walk_speed_tenths': 35, 'min_walk': 4, 'yellow_tenths': 35, 'red_tenths': 15, 'min_green': 10, 'ped_call': True, 'split': 35}, {'walk': 6, 'fdw': 26, 'green': 27, 'fits': True}), ({'crossing_ft': 96, 'walk_speed_tenths': 35, 'min_walk': 5, 'yellow_tenths': 40, 'red_tenths': 10, 'min_green': 8, 'ped_call': False, 'split': 21}, {'walk': 6, 'fdw': 28, 'green': 8, 'fits': True}), ({'crossing_ft': 70, 'walk_speed_tenths': 35, 'min_walk': 7, 'yellow_tenths': 40, 'red_tenths': 20, 'min_green': 5, 'ped_call': True, 'split': 30}, {'walk': 7, 'fdw': 20, 'green': 21, 'fits': True}), ({'crossing_ft': 81, 'walk_speed_tenths': 35, 'min_walk': 10, 'yellow_tenths': 30, 'red_tenths': 10, 'min_green': 5, 'ped_call': True, 'split': 30}, {'walk': 10, 'fdw': 24, 'green': 30, 'fits': False}), ({'crossing_ft': 45, 'walk_speed_tenths': 35, 'min_walk': 7, 'yellow_tenths': 30, 'red_tenths': 20, 'min_green': 5, 'ped_call': False, 'split': 41}, {'walk': 7, 'fdw': 13, 'green': 5, 'fits': True})], [({'crossing_ft': 65, 'walk_speed_tenths': 35, 'min_walk': 5, 'yellow_tenths': 40, 'red_tenths': 10, 'min_green': 10, 'ped_call': True, 'split': 40}, {'walk': 5, 'fdw': 19, 'green': 19, 'fits': True}), ({'crossing_ft': 87, 'walk_speed_tenths': 35, 'min_walk': 10, 'yellow_tenths': 45, 'red_tenths': 10, 'min_green': 15, 'ped_call': True, 'split': 38}, {'walk': 10, 'fdw': 25, 'green': 30, 'fits': True}), ({'crossing_ft': 90, 'walk_speed_tenths': 35, 'min_walk': 4, 'yellow_tenths': 35, 'red_tenths': 15, 'min_green': 10, 'ped_call': True, 'split': 35}, {'walk': 6, 'fdw': 26, 'green': 27, 'fits': True}), ({'crossing_ft': 85, 'walk_speed_tenths': 30, 'min_walk': 5, 'yellow_tenths': 45, 'red_tenths': 15, 'min_green': 8, 'ped_call': True, 'split': 28}, {'walk': 5, 'fdw': 29, 'green': 28, 'fits': False}), ({'crossing_ft': 70, 'walk_speed_tenths': 35, 'min_walk': 7, 'yellow_tenths': 40, 'red_tenths': 20, 'min_green': 5, 'ped_call': True, 'split': 30}, {'walk': 7, 'fdw': 20, 'green': 21, 'fits': True}), ({'crossing_ft': 92, 'walk_speed_tenths': 35, 'min_walk': 7, 'yellow_tenths': 30, 'red_tenths': 20, 'min_green': 10, 'ped_call': True, 'split': 34}, {'walk': 7, 'fdw': 27, 'green': 29, 'fits': True}), ({'crossing_ft': 36, 'walk_speed_tenths': 40, 'min_walk': 7, 'yellow_tenths': 30, 'red_tenths': 10, 'min_green': 8, 'ped_call': False, 'split': 12}, {'walk': 7, 'fdw': 9, 'green': 8, 'fits': True}), ({'crossing_ft': 64, 'walk_speed_tenths': 30, 'min_walk': 4, 'yellow_tenths': 30, 'red_tenths': 20, 'min_green': 8, 'ped_call': True, 'split': 21}, {'walk': 4, 'fdw': 22, 'green': 21, 'fits': False})]]
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{'fdw': 1, 'fits': True, 'green': 8, 'walk': 13}{'fdw': 9, 'fits': True, 'green': 8, 'walk': 7}Failed
timing oracle 1{'fdw': 2, 'fits': True, 'green': 20, 'walk': 24}{'fdw': 20, 'fits': True, 'green': 21, 'walk': 7}Failed
timing oracle 2{'fdw': 3, 'fits': True, 'green': 27, 'walk': 29}{'fdw': 26, 'fits': True, 'green': 27, 'walk': 6}Failed
timing oracle 3{'fdw': 1, 'fits': True, 'green': 10, 'walk': 10}{'fdw': 9, 'fits': True, 'green': 10, 'walk': 5}Failed
timing oracle 4{'fdw': 4, 'fits': True, 'green': 34, 'walk': 35}{'fdw': 32, 'fits': True, 'green': 34, 'walk': 7}Failed
timing oracle 5{'fdw': 2, 'fits': True, 'green': 11, 'walk': 14}{'fdw': 11, 'fits': True, 'green': 11, 'walk': 5}Failed
timing oracle 6{'fdw': 3, 'fits': False, 'green': 22, 'walk': 24}{'fdw': 25, 'fits': False, 'green': 27, 'walk': 7}Failed
timing oracle 7{'fdw': 3, 'fits': True, 'green': 8, 'walk': 29}{'fdw': 26, 'fits': True, 'green': 8, 'walk': 10}Failed

SHA-256 / 999465da00aedf3fdc07c93c5bb8d09f4f6d884e545359dc04e5202d0c7f57b6

HELD IN THE MEMBER ARCHIVE

The verified repair and its recorded checks are member-only.

This mechanism has 8 recorded checks per implementation. The open-access tier publishes the failure and the unsuccessful fix; the repaired source that passes every check, and the observations that prove it, are available to members.

Every case sharing this mechanism uses the same contract and the same repair, so this one record is held back for all of them.

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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 2026-09-29T14:47:57.594238+00:00.

Case digest / 663dcda2c78342af46e7403d53855faf1f7175bdc44a4fdcbdbd6e63d053e92a