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FA-63321 / Insurance premium rating / Open access

Usage-based auto telematics discount: Brake rate averages per-trip ratios · case 01

Short trips with a single brake event dominate the score.

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

ROOT CAUSE

The score averages per-trip rates instead of dividing total brakes by total miles.

VERIFIED REPAIR

Use total brakes per 100 total miles.

Unsuccessful approach: Dividing by trip count measures brakes per trip.

Case contract

Input base, annual_miles (bands <=5000 0.85, <=10000 1.00, <=15000 1.10, else 1.25), trips [[miles, hard brakes]], min_trips. With at least min_trips trips: bp = total brakes per 100 total miles; discount = clamp(300-50*bp, -100, 300) per mille. Fewer (but some) trips: 50 per mille participation discount; none: 0. Premium = base*band*(1000-discount)/1000 half-up.

Why this case matters

Telematics programs mix mileage bands with behaviour scores and participation rules.

1 / The failure

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json
import math
from fractions import Fraction
N = 1
observations = []
def solve(x):
    m=x['annual_miles']
    if m<=5000: band=Fraction(85,100)
    elif m<=10000: band=Fraction(1)
    elif m<=15000: band=Fraction(110,100)
    else: band=Fraction(125,100)
    trips=x['trips']
    if len(trips)>=x['min_trips']:
        miles=sum(t[0] for t in trips); brakes=sum(t[1] for t in trips)
        bp=sum(Fraction(t[1]*100,t[0]) for t in trips if t[0])/len(trips)
        disc=max(-100,min(300,300-50*bp))
    elif trips:
        disc=Fraction(50)
    else:
        disc=Fraction(0)
    return math.floor(x['base']*band*(1000-disc)/1000+Fraction(1,2))
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['mileage 10000 boundary', {'base': 91494, 'annual_miles': 10000, 'trips': [[9, 0], [23, 1], [20, 0], [13, 1], [26, 0], [39, 1]], 'min_trips': 5}, 74603], ['mileage 10300', {'base': 82749, 'annual_miles': 10300, 'trips': [[30, 0], [20, 0], [15, 0], [29, 0], [14, 0], [8, 2], [23, 0]], 'min_trips': 5}, 70265], ['careful driver', {'base': 163637, 'annual_miles': 7341, 'trips': [[30, 1], [8, 2], [6, 0], [14, 2], [39, 2], [11, 1], [14, 1], [28, 1]], 'min_trips': 5}, 169092], ['harsh braker surcharged', {'base': 91954, 'annual_miles': 14146, 'trips': [[5, 6], [4, 5], [6, 7], [3, 4], [5, 6]], 'min_trips': 5}, 111264], ['uneven trip lengths', {'base': 158528, 'annual_miles': 2875, 'trips': [[80, 2], [2, 1], [60, 1], [3, 0], [50, 2]], 'min_trips': 5}, 115055], ['exactly minimum trips', {'base': 104301, 'annual_miles': 17231, 'trips': [[5, 2], [19, 0], [32, 0], [19, 0], [8, 2]], 'min_trips': 5}, 122679], ['few trips participation', {'base': 97679, 'annual_miles': 12000, 'trips': [[16, 1], [7, 2], [36, 1]], 'min_trips': 5}, 102075], ['no trips', {'base': 134485, 'annual_miles': 4000, 'trips': [], 'min_trips': 5}, 114312]], [['mileage 10000 boundary', {'base': 191368, 'annual_miles': 10000, 'trips': [[27, 0], [10, 0], [40, 1], [30, 2], [32, 1], [25, 2]], 'min_trips': 5}, 168964], ['mileage 10300', {'base': 105555, 'annual_miles': 10300, 'trips': [[29, 1], [13, 0], [15, 1], [29, 0], [39, 0], [15, 2], [17, 1]], 'min_trips': 5}, 99766], ['careful driver', {'base': 102660, 'annual_miles': 8401, 'trips': [[3, 1], [19, 0], [12, 2], [23, 0], [4, 0], [9, 0], [37, 2], [3, 1]], 'min_trips': 5}, 99860], ['harsh braker surcharged', {'base': 180490, 'annual_miles': 14814, 'trips': [[5, 6], [4, 5], [6, 7], [3, 4], [5, 6]], 'min_trips': 5}, 218393], ['uneven trip lengths', {'base': 153152, 'annual_miles': 2570, 'trips': [[80, 2], [2, 1], [60, 1], [3, 0], [50, 2]], 'min_trips': 5}, 111153], ['exactly minimum trips', {'base': 128499, 'annual_miles': 20368, 'trips': [[14, 0], [32, 2], [33, 0], [37, 2], [39, 0]], 'min_trips': 5}, 133162], ['few trips participation', {'base': 120795, 'annual_miles': 12000, 'trips': [[24, 0], [17, 2], [14, 2]], 'min_trips': 5}, 126231], ['no trips', {'base': 91464, 'annual_miles': 4000, 'trips': [], 'min_trips': 5}, 77744]], [['mileage 10000 boundary', {'base': 137312, 'annual_miles': 10000, 'trips': [[17, 0], [26, 0], [22, 0], [27, 0], [31, 0], [14, 0]], 'min_trips': 5}, 96118], ['mileage 10300', {'base': 96030, 'annual_miles': 10300, 'trips': [[16, 0], [14, 2], [3, 2], [27, 2], [34, 2], [28, 0], [15, 1]], 'min_trips': 5}, 108640], ['careful driver', {'base': 119620, 'annual_miles': 6579, 'trips': [[37, 0], [24, 1], [19, 0], [4, 2], [18, 0], [38, 0], [13, 0], [28, 1]], 'min_trips': 5}, 96952], ['harsh braker surcharged', {'base': 69899, 'annual_miles': 13431, 'trips': [[5, 6], [4, 5], [6, 7], [3, 4], [5, 6]], 'min_trips': 5}, 84578], ['uneven trip lengths', {'base': 78689, 'annual_miles': 3827, 'trips': [[80, 2], [2, 1], [60, 1], [3, 0], [50, 2]], 'min_trips': 5}, 57110], ['exactly minimum trips', {'base': 151953, 'annual_miles': 21023, 'trips': [[11, 2], [21, 0], [12, 1], [31, 1], [34, 0]], 'min_trips': 5}, 167810], ['few trips participation', {'base': 175401, 'annual_miles': 12000, 'trips': [[4, 0], [3, 1], [16, 0]], 'min_trips': 5}, 183294], ['no trips', {'base': 63313, 'annual_miles': 4000, 'trips': [], 'min_trips': 5}, 53816]], [['mileage 10000 boundary', {'base': 97658, 'annual_miles': 10000, 'trips': [[3, 0], [31, 0], [16, 0], [17, 2], [9, 0], [6, 2]], 'min_trips': 5}, 92180], ['mileage 10300', {'base': 197346, 'annual_miles': 10300, 'trips': [[29, 0], [26, 2], [5, 0], [24, 0], [37, 0], [26, 2], [36, 0]], 'min_trips': 5}, 175681], ['careful driver', {'base': 162245, 'annual_miles': 5217, 'trips': [[20, 0], [35, 0], [30, 0], [10, 0], [31, 0], [11, 0], [34, 1], [21, 0]], 'min_trips': 5}, 117797], ['harsh braker surcharged', {'base': 110905, 'annual_miles': 12698, 'trips': [[5, 6], [4, 5], [6, 7], [3, 4], [5, 6]], 'min_trips': 5}, 134195], ['uneven trip lengths', {'base': 170601, 'annual_miles': 3861, 'trips': [[80, 2], [2, 1], [60, 1], [3, 0], [50, 2]], 'min_trips': 5}, 123817], ['exactly minimum trips', {'base': 139426, 'annual_miles': 27324, 'trips': [[7, 1], [31, 1], [40, 2], [10, 2], [19, 1]], 'min_trips': 5}, 179006], ['few trips participation', {'base': 116838, 'annual_miles': 12000, 'trips': [[6, 2], [28, 1], [31, 2]], 'min_trips': 5}, 122096], ['no trips', {'base': 196384, 'annual_miles': 4000, 'trips': [], 'min_trips': 5}, 166926]], [['mileage 10000 boundary', {'base': 176617, 'annual_miles': 10000, 'trips': [[15, 1], [20, 0], [31, 1], [6, 0], [25, 0], [24, 0]], 'min_trips': 5}, 138228], ['mileage 10300', {'base': 171140, 'annual_miles': 10300, 'trips': [[19, 2], [13, 0], [34, 0], [19, 2], [11, 0], [3, 0], [32, 0]], 'min_trips': 5}, 160519], ['careful driver', {'base': 154323, 'annual_miles': 7789, 'trips': [[36, 0], [35, 0], [22, 1], [7, 1], [30, 2], [34, 1], [32, 2], [18, 0]], 'min_trips': 5}, 133266], ['harsh braker surcharged', {'base': 124651, 'annual_miles': 10146, 'trips': [[5, 6], [4, 5], [6, 7], [3, 4], [5, 6]], 'min_trips': 5}, 150828], ['uneven trip lengths', {'base': 133061, 'annual_miles': 2552, 'trips': [[80, 2], [2, 1], [60, 1], [3, 0], [50, 2]], 'min_trips': 5}, 96572], ['exactly minimum trips', {'base': 110232, 'annual_miles': 28818, 'trips': [[13, 0], [24, 0], [28, 0], [40, 0], [36, 1]], 'min_trips': 5}, 101339], ['few trips participation', {'base': 156778, 'annual_miles': 12000, 'trips': [[3, 0], [5, 0], [8, 0]], 'min_trips': 5}, 163833], ['no trips', {'base': 82109, 'annual_miles': 4000, 'trips': [], 'min_trips': 5}, 69793]]]
for label, args, expected in fixtures[N-1]:
    check(label, 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
mileage 10000 boundary7518174603Failed
mileage 103007997170265Failed
careful driver180001169092Failed
harsh braker surcharged111264111264Passed
uneven trip lengths148224115055Failed
exactly minimum trips143414122679Failed
few trips participation102075102075Passed
no trips114312114312Passed

SHA-256 / c64ebd4991b36d00d483796d1e7f42dba5c64f6b1e832af8ba4ec29462b92ae1

2 / The unsuccessful fix

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json
import math
from fractions import Fraction
N = 1
observations = []
def solve(x):
    m=x['annual_miles']
    if m<=5000: band=Fraction(85,100)
    elif m<=10000: band=Fraction(1)
    elif m<=15000: band=Fraction(110,100)
    else: band=Fraction(125,100)
    trips=x['trips']
    if len(trips)>=x['min_trips']:
        miles=sum(t[0] for t in trips); brakes=sum(t[1] for t in trips)
        bp=Fraction(brakes*100,len(trips))
        disc=max(-100,min(300,300-50*bp))
    elif trips:
        disc=Fraction(50)
    else:
        disc=Fraction(0)
    return math.floor(x['base']*band*(1000-disc)/1000+Fraction(1,2))
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['mileage 10000 boundary', {'base': 91494, 'annual_miles': 10000, 'trips': [[9, 0], [23, 1], [20, 0], [13, 1], [26, 0], [39, 1]], 'min_trips': 5}, 74603], ['mileage 10300', {'base': 82749, 'annual_miles': 10300, 'trips': [[30, 0], [20, 0], [15, 0], [29, 0], [14, 0], [8, 2], [23, 0]], 'min_trips': 5}, 70265], ['careful driver', {'base': 163637, 'annual_miles': 7341, 'trips': [[30, 1], [8, 2], [6, 0], [14, 2], [39, 2], [11, 1], [14, 1], [28, 1]], 'min_trips': 5}, 169092], ['harsh braker surcharged', {'base': 91954, 'annual_miles': 14146, 'trips': [[5, 6], [4, 5], [6, 7], [3, 4], [5, 6]], 'min_trips': 5}, 111264], ['uneven trip lengths', {'base': 158528, 'annual_miles': 2875, 'trips': [[80, 2], [2, 1], [60, 1], [3, 0], [50, 2]], 'min_trips': 5}, 115055], ['exactly minimum trips', {'base': 104301, 'annual_miles': 17231, 'trips': [[5, 2], [19, 0], [32, 0], [19, 0], [8, 2]], 'min_trips': 5}, 122679], ['few trips participation', {'base': 97679, 'annual_miles': 12000, 'trips': [[16, 1], [7, 2], [36, 1]], 'min_trips': 5}, 102075], ['no trips', {'base': 134485, 'annual_miles': 4000, 'trips': [], 'min_trips': 5}, 114312]], [['mileage 10000 boundary', {'base': 191368, 'annual_miles': 10000, 'trips': [[27, 0], [10, 0], [40, 1], [30, 2], [32, 1], [25, 2]], 'min_trips': 5}, 168964], ['mileage 10300', {'base': 105555, 'annual_miles': 10300, 'trips': [[29, 1], [13, 0], [15, 1], [29, 0], [39, 0], [15, 2], [17, 1]], 'min_trips': 5}, 99766], ['careful driver', {'base': 102660, 'annual_miles': 8401, 'trips': [[3, 1], [19, 0], [12, 2], [23, 0], [4, 0], [9, 0], [37, 2], [3, 1]], 'min_trips': 5}, 99860], ['harsh braker surcharged', {'base': 180490, 'annual_miles': 14814, 'trips': [[5, 6], [4, 5], [6, 7], [3, 4], [5, 6]], 'min_trips': 5}, 218393], ['uneven trip lengths', {'base': 153152, 'annual_miles': 2570, 'trips': [[80, 2], [2, 1], [60, 1], [3, 0], [50, 2]], 'min_trips': 5}, 111153], ['exactly minimum trips', {'base': 128499, 'annual_miles': 20368, 'trips': [[14, 0], [32, 2], [33, 0], [37, 2], [39, 0]], 'min_trips': 5}, 133162], ['few trips participation', {'base': 120795, 'annual_miles': 12000, 'trips': [[24, 0], [17, 2], [14, 2]], 'min_trips': 5}, 126231], ['no trips', {'base': 91464, 'annual_miles': 4000, 'trips': [], 'min_trips': 5}, 77744]], [['mileage 10000 boundary', {'base': 137312, 'annual_miles': 10000, 'trips': [[17, 0], [26, 0], [22, 0], [27, 0], [31, 0], [14, 0]], 'min_trips': 5}, 96118], ['mileage 10300', {'base': 96030, 'annual_miles': 10300, 'trips': [[16, 0], [14, 2], [3, 2], [27, 2], [34, 2], [28, 0], [15, 1]], 'min_trips': 5}, 108640], ['careful driver', {'base': 119620, 'annual_miles': 6579, 'trips': [[37, 0], [24, 1], [19, 0], [4, 2], [18, 0], [38, 0], [13, 0], [28, 1]], 'min_trips': 5}, 96952], ['harsh braker surcharged', {'base': 69899, 'annual_miles': 13431, 'trips': [[5, 6], [4, 5], [6, 7], [3, 4], [5, 6]], 'min_trips': 5}, 84578], ['uneven trip lengths', {'base': 78689, 'annual_miles': 3827, 'trips': [[80, 2], [2, 1], [60, 1], [3, 0], [50, 2]], 'min_trips': 5}, 57110], ['exactly minimum trips', {'base': 151953, 'annual_miles': 21023, 'trips': [[11, 2], [21, 0], [12, 1], [31, 1], [34, 0]], 'min_trips': 5}, 167810], ['few trips participation', {'base': 175401, 'annual_miles': 12000, 'trips': [[4, 0], [3, 1], [16, 0]], 'min_trips': 5}, 183294], ['no trips', {'base': 63313, 'annual_miles': 4000, 'trips': [], 'min_trips': 5}, 53816]], [['mileage 10000 boundary', {'base': 97658, 'annual_miles': 10000, 'trips': [[3, 0], [31, 0], [16, 0], [17, 2], [9, 0], [6, 2]], 'min_trips': 5}, 92180], ['mileage 10300', {'base': 197346, 'annual_miles': 10300, 'trips': [[29, 0], [26, 2], [5, 0], [24, 0], [37, 0], [26, 2], [36, 0]], 'min_trips': 5}, 175681], ['careful driver', {'base': 162245, 'annual_miles': 5217, 'trips': [[20, 0], [35, 0], [30, 0], [10, 0], [31, 0], [11, 0], [34, 1], [21, 0]], 'min_trips': 5}, 117797], ['harsh braker surcharged', {'base': 110905, 'annual_miles': 12698, 'trips': [[5, 6], [4, 5], [6, 7], [3, 4], [5, 6]], 'min_trips': 5}, 134195], ['uneven trip lengths', {'base': 170601, 'annual_miles': 3861, 'trips': [[80, 2], [2, 1], [60, 1], [3, 0], [50, 2]], 'min_trips': 5}, 123817], ['exactly minimum trips', {'base': 139426, 'annual_miles': 27324, 'trips': [[7, 1], [31, 1], [40, 2], [10, 2], [19, 1]], 'min_trips': 5}, 179006], ['few trips participation', {'base': 116838, 'annual_miles': 12000, 'trips': [[6, 2], [28, 1], [31, 2]], 'min_trips': 5}, 122096], ['no trips', {'base': 196384, 'annual_miles': 4000, 'trips': [], 'min_trips': 5}, 166926]], [['mileage 10000 boundary', {'base': 176617, 'annual_miles': 10000, 'trips': [[15, 1], [20, 0], [31, 1], [6, 0], [25, 0], [24, 0]], 'min_trips': 5}, 138228], ['mileage 10300', {'base': 171140, 'annual_miles': 10300, 'trips': [[19, 2], [13, 0], [34, 0], [19, 2], [11, 0], [3, 0], [32, 0]], 'min_trips': 5}, 160519], ['careful driver', {'base': 154323, 'annual_miles': 7789, 'trips': [[36, 0], [35, 0], [22, 1], [7, 1], [30, 2], [34, 1], [32, 2], [18, 0]], 'min_trips': 5}, 133266], ['harsh braker surcharged', {'base': 124651, 'annual_miles': 10146, 'trips': [[5, 6], [4, 5], [6, 7], [3, 4], [5, 6]], 'min_trips': 5}, 150828], ['uneven trip lengths', {'base': 133061, 'annual_miles': 2552, 'trips': [[80, 2], [2, 1], [60, 1], [3, 0], [50, 2]], 'min_trips': 5}, 96572], ['exactly minimum trips', {'base': 110232, 'annual_miles': 28818, 'trips': [[13, 0], [24, 0], [28, 0], [40, 0], [36, 1]], 'min_trips': 5}, 101339], ['few trips participation', {'base': 156778, 'annual_miles': 12000, 'trips': [[3, 0], [5, 0], [8, 0]], 'min_trips': 5}, 163833], ['no trips', {'base': 82109, 'annual_miles': 4000, 'trips': [], 'min_trips': 5}, 69793]]]
for label, args, expected in fixtures[N-1]:
    check(label, 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
mileage 10000 boundary10064374603Failed
mileage 1030010012670265Failed
careful driver180001169092Failed
harsh braker surcharged111264111264Passed
uneven trip lengths148224115055Failed
exactly minimum trips143414122679Failed
few trips participation102075102075Passed
no trips114312114312Passed

SHA-256 / 7f096fb07c66fc5858e7488238abb5b6e4dbfe5a36a2a9b7cf0dc83f9b538543

3 / The verified repair

Exit 0
"""Failure Map reference implementation. Python standard library only."""
import json
import math
from fractions import Fraction
N = 1
observations = []
def solve(x):
    m=x['annual_miles']
    if m<=5000: band=Fraction(85,100)
    elif m<=10000: band=Fraction(1)
    elif m<=15000: band=Fraction(110,100)
    else: band=Fraction(125,100)
    trips=x['trips']
    if len(trips)>=x['min_trips']:
        miles=sum(t[0] for t in trips); brakes=sum(t[1] for t in trips)
        bp=Fraction(brakes*100,miles) if miles else Fraction(0)
        disc=max(-100,min(300,300-50*bp))
    elif trips:
        disc=Fraction(50)
    else:
        disc=Fraction(0)
    return math.floor(x['base']*band*(1000-disc)/1000+Fraction(1,2))
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['mileage 10000 boundary', {'base': 91494, 'annual_miles': 10000, 'trips': [[9, 0], [23, 1], [20, 0], [13, 1], [26, 0], [39, 1]], 'min_trips': 5}, 74603], ['mileage 10300', {'base': 82749, 'annual_miles': 10300, 'trips': [[30, 0], [20, 0], [15, 0], [29, 0], [14, 0], [8, 2], [23, 0]], 'min_trips': 5}, 70265], ['careful driver', {'base': 163637, 'annual_miles': 7341, 'trips': [[30, 1], [8, 2], [6, 0], [14, 2], [39, 2], [11, 1], [14, 1], [28, 1]], 'min_trips': 5}, 169092], ['harsh braker surcharged', {'base': 91954, 'annual_miles': 14146, 'trips': [[5, 6], [4, 5], [6, 7], [3, 4], [5, 6]], 'min_trips': 5}, 111264], ['uneven trip lengths', {'base': 158528, 'annual_miles': 2875, 'trips': [[80, 2], [2, 1], [60, 1], [3, 0], [50, 2]], 'min_trips': 5}, 115055], ['exactly minimum trips', {'base': 104301, 'annual_miles': 17231, 'trips': [[5, 2], [19, 0], [32, 0], [19, 0], [8, 2]], 'min_trips': 5}, 122679], ['few trips participation', {'base': 97679, 'annual_miles': 12000, 'trips': [[16, 1], [7, 2], [36, 1]], 'min_trips': 5}, 102075], ['no trips', {'base': 134485, 'annual_miles': 4000, 'trips': [], 'min_trips': 5}, 114312]], [['mileage 10000 boundary', {'base': 191368, 'annual_miles': 10000, 'trips': [[27, 0], [10, 0], [40, 1], [30, 2], [32, 1], [25, 2]], 'min_trips': 5}, 168964], ['mileage 10300', {'base': 105555, 'annual_miles': 10300, 'trips': [[29, 1], [13, 0], [15, 1], [29, 0], [39, 0], [15, 2], [17, 1]], 'min_trips': 5}, 99766], ['careful driver', {'base': 102660, 'annual_miles': 8401, 'trips': [[3, 1], [19, 0], [12, 2], [23, 0], [4, 0], [9, 0], [37, 2], [3, 1]], 'min_trips': 5}, 99860], ['harsh braker surcharged', {'base': 180490, 'annual_miles': 14814, 'trips': [[5, 6], [4, 5], [6, 7], [3, 4], [5, 6]], 'min_trips': 5}, 218393], ['uneven trip lengths', {'base': 153152, 'annual_miles': 2570, 'trips': [[80, 2], [2, 1], [60, 1], [3, 0], [50, 2]], 'min_trips': 5}, 111153], ['exactly minimum trips', {'base': 128499, 'annual_miles': 20368, 'trips': [[14, 0], [32, 2], [33, 0], [37, 2], [39, 0]], 'min_trips': 5}, 133162], ['few trips participation', {'base': 120795, 'annual_miles': 12000, 'trips': [[24, 0], [17, 2], [14, 2]], 'min_trips': 5}, 126231], ['no trips', {'base': 91464, 'annual_miles': 4000, 'trips': [], 'min_trips': 5}, 77744]], [['mileage 10000 boundary', {'base': 137312, 'annual_miles': 10000, 'trips': [[17, 0], [26, 0], [22, 0], [27, 0], [31, 0], [14, 0]], 'min_trips': 5}, 96118], ['mileage 10300', {'base': 96030, 'annual_miles': 10300, 'trips': [[16, 0], [14, 2], [3, 2], [27, 2], [34, 2], [28, 0], [15, 1]], 'min_trips': 5}, 108640], ['careful driver', {'base': 119620, 'annual_miles': 6579, 'trips': [[37, 0], [24, 1], [19, 0], [4, 2], [18, 0], [38, 0], [13, 0], [28, 1]], 'min_trips': 5}, 96952], ['harsh braker surcharged', {'base': 69899, 'annual_miles': 13431, 'trips': [[5, 6], [4, 5], [6, 7], [3, 4], [5, 6]], 'min_trips': 5}, 84578], ['uneven trip lengths', {'base': 78689, 'annual_miles': 3827, 'trips': [[80, 2], [2, 1], [60, 1], [3, 0], [50, 2]], 'min_trips': 5}, 57110], ['exactly minimum trips', {'base': 151953, 'annual_miles': 21023, 'trips': [[11, 2], [21, 0], [12, 1], [31, 1], [34, 0]], 'min_trips': 5}, 167810], ['few trips participation', {'base': 175401, 'annual_miles': 12000, 'trips': [[4, 0], [3, 1], [16, 0]], 'min_trips': 5}, 183294], ['no trips', {'base': 63313, 'annual_miles': 4000, 'trips': [], 'min_trips': 5}, 53816]], [['mileage 10000 boundary', {'base': 97658, 'annual_miles': 10000, 'trips': [[3, 0], [31, 0], [16, 0], [17, 2], [9, 0], [6, 2]], 'min_trips': 5}, 92180], ['mileage 10300', {'base': 197346, 'annual_miles': 10300, 'trips': [[29, 0], [26, 2], [5, 0], [24, 0], [37, 0], [26, 2], [36, 0]], 'min_trips': 5}, 175681], ['careful driver', {'base': 162245, 'annual_miles': 5217, 'trips': [[20, 0], [35, 0], [30, 0], [10, 0], [31, 0], [11, 0], [34, 1], [21, 0]], 'min_trips': 5}, 117797], ['harsh braker surcharged', {'base': 110905, 'annual_miles': 12698, 'trips': [[5, 6], [4, 5], [6, 7], [3, 4], [5, 6]], 'min_trips': 5}, 134195], ['uneven trip lengths', {'base': 170601, 'annual_miles': 3861, 'trips': [[80, 2], [2, 1], [60, 1], [3, 0], [50, 2]], 'min_trips': 5}, 123817], ['exactly minimum trips', {'base': 139426, 'annual_miles': 27324, 'trips': [[7, 1], [31, 1], [40, 2], [10, 2], [19, 1]], 'min_trips': 5}, 179006], ['few trips participation', {'base': 116838, 'annual_miles': 12000, 'trips': [[6, 2], [28, 1], [31, 2]], 'min_trips': 5}, 122096], ['no trips', {'base': 196384, 'annual_miles': 4000, 'trips': [], 'min_trips': 5}, 166926]], [['mileage 10000 boundary', {'base': 176617, 'annual_miles': 10000, 'trips': [[15, 1], [20, 0], [31, 1], [6, 0], [25, 0], [24, 0]], 'min_trips': 5}, 138228], ['mileage 10300', {'base': 171140, 'annual_miles': 10300, 'trips': [[19, 2], [13, 0], [34, 0], [19, 2], [11, 0], [3, 0], [32, 0]], 'min_trips': 5}, 160519], ['careful driver', {'base': 154323, 'annual_miles': 7789, 'trips': [[36, 0], [35, 0], [22, 1], [7, 1], [30, 2], [34, 1], [32, 2], [18, 0]], 'min_trips': 5}, 133266], ['harsh braker surcharged', {'base': 124651, 'annual_miles': 10146, 'trips': [[5, 6], [4, 5], [6, 7], [3, 4], [5, 6]], 'min_trips': 5}, 150828], ['uneven trip lengths', {'base': 133061, 'annual_miles': 2552, 'trips': [[80, 2], [2, 1], [60, 1], [3, 0], [50, 2]], 'min_trips': 5}, 96572], ['exactly minimum trips', {'base': 110232, 'annual_miles': 28818, 'trips': [[13, 0], [24, 0], [28, 0], [40, 0], [36, 1]], 'min_trips': 5}, 101339], ['few trips participation', {'base': 156778, 'annual_miles': 12000, 'trips': [[3, 0], [5, 0], [8, 0]], 'min_trips': 5}, 163833], ['no trips', {'base': 82109, 'annual_miles': 4000, 'trips': [], 'min_trips': 5}, 69793]]]
for label, args, expected in fixtures[N-1]:
    check(label, 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
mileage 10000 boundary7460374603Passed
mileage 103007026570265Passed
careful driver169092169092Passed
harsh braker surcharged111264111264Passed
uneven trip lengths115055115055Passed
exactly minimum trips122679122679Passed
few trips participation102075102075Passed
no trips114312114312Passed

SHA-256 / 0c627dc8da4543aaeb45c08897a68bbc923f8d482e820296f5a5ab9b0536a05a

Verification & scope

A deterministic bounded teaching model of a stipulated toy rating contract. Amounts are integer cents and factors exact rationals; it makes no claim of conformance with any filed rating plan, bureau manual or jurisdiction. 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 2026-09-29T14:47:13.236194+00:00.

Case digest / d7ed6c9208920f52124ea4a1cb47aa8c9c2ca1f584d01c1d28bc1582ffbefa4a