POSTCODE RISK LAB

Do geographic differences persist?

Explore road outcomes across authorities and test whether differences recur in later years. These public proxies do not measure postcode-level insurance claims.

Public geographic evidence. Johan’s five proprietary Postcode Risk Indices are not published here. Their definitions and inputs still require validation and approval.

Explore geographic evidence

2016–2025 · Counties and unitary authorities, December 2025

THE ACTUARY LENSGEOGRAPHY · EVIDENCE · PERSISTENCE

Beyond Postcodes — Geo Risk

Unpack geography. Follow the risk. Test whether the differences endure.

Read the white paper

Official sources · 2016–2025207 areas · 2,070 area-yearsPublic evidence, not a validated insurance tariff

Methods & limits · County Durham · Injury collision frequency · Map year 2025 · History 2016–2025 · Assessment 2022–2025

Release and terminology

lens-2026-10-04-59b57c37396f

KSI = killed or seriously injured. FSC = fatal or serious collisions. GB = Great Britain. UK = United Kingdom. DfT = Department for Transport. ONS = Office for National Statistics. PFA = police force area. NRD = National Receptor Dataset. These public outcomes are not insurance claim costs.

Fixed-panel benchmark: membership, weighting and limits

190 of 207 Great Britain county / unitary authorities have an unflagged observation and non-missing motor mileage in every released year (2016–2025). The same panel is used each year. It is not the complete national total or a match on risk characteristics.

Rate = sum of relevant events ÷ sum of motor vehicle miles × 100,000. Severity share uses summed serious/fatal collisions ÷ summed injury collisions × 100. Traffic sums motor mileage, expressed in billions. These are ratios of sums, not an average of area rates.

The selected authority is included in the benchmark. Self-inclusion creates dependence. Relative differences have no confidence interval here. Completeness selection can bias the benchmark; it does not control confounding.

Authority	Panel eligibility
County Durham	Included for every year
Darlington	Included for every year
Gateshead	Included for every year
Hartlepool	Included for every year
Middlesbrough	Included for every year
Newcastle upon Tyne	Included for every year
North Tyneside	Included for every year
Northumberland	Included for every year
Redcar and Cleveland	Included for every year
South Tyneside	Included for every year
Stockton-on-Tees	Included for every year
Sunderland	Included for every year
Blackburn with Darwen	Included for every year
Blackpool	Included for every year
Bolton	Included for every year
Bury	Included for every year
Cheshire East	Included for every year
Cheshire West and Chester	Included for every year
Cumberland	Excluded: 2016: No matching traffic authority code and year; mileage rate withheld; 2017: No matching traffic authority code and year; mileage rate withheld; 2018: No matching traffic authority code and year; mileage rate withheld; 2019: No matching traffic authority code and year; mileage rate withheld; 2020: No matching traffic authority code and year; mileage rate withheld; 2021: No matching traffic authority code and year; mileage rate withheld; 2022: No matching traffic authority code and year; mileage rate withheld
Halton	Included for every year
Knowsley	Included for every year
Lancashire	Included for every year
Liverpool	Included for every year
Manchester	Included for every year
Oldham	Included for every year
Rochdale	Included for every year
Salford	Included for every year
Sefton	Included for every year
St. Helens	Included for every year
Stockport	Included for every year
Tameside	Included for every year
Trafford	Included for every year
Warrington	Included for every year
Westmorland and Furness	Excluded: 2016: No matching traffic authority code and year; mileage rate withheld; 2017: No matching traffic authority code and year; mileage rate withheld; 2018: No matching traffic authority code and year; mileage rate withheld; 2019: No matching traffic authority code and year; mileage rate withheld; 2020: No matching traffic authority code and year; mileage rate withheld; 2021: No matching traffic authority code and year; mileage rate withheld; 2022: No matching traffic authority code and year; mileage rate withheld
Wigan	Included for every year
Wirral	Included for every year
Barnsley	Excluded: 2016: No matching traffic authority code and year; mileage rate withheld; 2017: No matching traffic authority code and year; mileage rate withheld; 2018: No matching traffic authority code and year; mileage rate withheld; 2019: No matching traffic authority code and year; mileage rate withheld; 2020: No matching traffic authority code and year; mileage rate withheld; 2021: No matching traffic authority code and year; mileage rate withheld; 2022: No matching traffic authority code and year; mileage rate withheld; 2023: No matching traffic authority code and year; mileage rate withheld; 2024: No matching traffic authority code and year; mileage rate withheld; 2025: No matching traffic authority code and year; mileage rate withheld
Bradford	Included for every year
Calderdale	Included for every year
Doncaster	Included for every year
East Riding of Yorkshire	Included for every year
Kingston upon Hull, City of	Included for every year
Kirklees	Included for every year
Leeds	Included for every year
North East Lincolnshire	Included for every year
North Lincolnshire	Included for every year
North Yorkshire	Included for every year
Rotherham	Included for every year
Sheffield	Excluded: 2016: No matching traffic authority code and year; mileage rate withheld; 2017: No matching traffic authority code and year; mileage rate withheld; 2018: No matching traffic authority code and year; mileage rate withheld; 2019: No matching traffic authority code and year; mileage rate withheld; 2020: No matching traffic authority code and year; mileage rate withheld; 2021: No matching traffic authority code and year; mileage rate withheld; 2022: No matching traffic authority code and year; mileage rate withheld; 2023: No matching traffic authority code and year; mileage rate withheld; 2024: No matching traffic authority code and year; mileage rate withheld; 2025: No matching traffic authority code and year; mileage rate withheld
Wakefield	Included for every year
York	Included for every year
Derby	Included for every year
Derbyshire	Included for every year
Leicester	Included for every year
Leicestershire	Included for every year
Lincolnshire	Included for every year
North Northamptonshire	Excluded: 2016: No matching traffic authority code and year; mileage rate withheld; 2017: No matching traffic authority code and year; mileage rate withheld; 2018: No matching traffic authority code and year; mileage rate withheld; 2019: No matching traffic authority code and year; mileage rate withheld; 2020: No matching traffic authority code and year; mileage rate withheld
Nottingham	Included for every year
Nottinghamshire	Included for every year
Rutland	Included for every year
West Northamptonshire	Excluded: 2016: No matching traffic authority code and year; mileage rate withheld; 2017: No matching traffic authority code and year; mileage rate withheld; 2018: No matching traffic authority code and year; mileage rate withheld; 2019: No matching traffic authority code and year; mileage rate withheld; 2020: No matching traffic authority code and year; mileage rate withheld
Birmingham	Included for every year
Coventry	Included for every year
Dudley	Included for every year
Herefordshire, County of	Included for every year
Sandwell	Included for every year
Shropshire	Included for every year
Solihull	Included for every year
Staffordshire	Excluded: 2022: DfT warning: Avon and Somerset / Staffordshire reporting may be incomplete; 2023: DfT warning: Avon and Somerset / Staffordshire reporting may be incomplete
Stoke-on-Trent	Excluded: 2022: DfT warning: Avon and Somerset / Staffordshire reporting may be incomplete; 2023: DfT warning: Avon and Somerset / Staffordshire reporting may be incomplete
Telford and Wrekin	Included for every year
Walsall	Included for every year
Warwickshire	Included for every year
Wolverhampton	Included for every year
Worcestershire	Included for every year
Bedford	Included for every year
Cambridgeshire	Included for every year
Central Bedfordshire	Included for every year
Essex	Included for every year
Hertfordshire	Included for every year
Luton	Included for every year
Norfolk	Included for every year
Peterborough	Included for every year
Southend-on-Sea	Included for every year
Suffolk	Included for every year
Thurrock	Included for every year
Barking and Dagenham	Included for every year
Barnet	Included for every year
Bexley	Included for every year
Brent	Included for every year
Bromley	Included for every year
Camden	Included for every year
City of London	Included for every year
Croydon	Included for every year
Ealing	Included for every year
Enfield	Included for every year
Greenwich	Included for every year
Hackney	Included for every year
Hammersmith and Fulham	Included for every year
Haringey	Included for every year
Harrow	Included for every year
Havering	Included for every year
Hillingdon	Included for every year
Hounslow	Included for every year
Islington	Included for every year
Kensington and Chelsea	Included for every year
Kingston upon Thames	Included for every year
Lambeth	Included for every year
Lewisham	Included for every year
Merton	Included for every year
Newham	Included for every year
Redbridge	Included for every year
Richmond upon Thames	Included for every year
Southwark	Included for every year
Sutton	Included for every year
Tower Hamlets	Included for every year
Waltham Forest	Included for every year
Wandsworth	Included for every year
Westminster	Included for every year
Bracknell Forest	Included for every year
Brighton and Hove	Included for every year
Buckinghamshire	Excluded: 2016: Official comparison rate unavailable; independent reconciliation not possible; 2017: Official comparison rate unavailable; independent reconciliation not possible; 2018: Official comparison rate unavailable; independent reconciliation not possible; 2019: Official comparison rate unavailable; independent reconciliation not possible; 2020: Official comparison rate unavailable; independent reconciliation not possible; 2021: Official comparison rate unavailable; independent reconciliation not possible; 2022: Official comparison rate unavailable; independent reconciliation not possible; 2023: Official comparison rate unavailable; independent reconciliation not possible; 2024: Official comparison rate unavailable; independent reconciliation not possible; 2025: Official comparison rate unavailable; independent reconciliation not possible
East Sussex	Included for every year
Hampshire	Included for every year
Isle of Wight	Included for every year
Kent	Included for every year
Medway	Included for every year
Milton Keynes	Included for every year
Oxfordshire	Included for every year
Portsmouth	Included for every year
Reading	Included for every year
Slough	Included for every year
Southampton	Included for every year
Surrey	Included for every year
West Berkshire	Included for every year
West Sussex	Included for every year
Windsor and Maidenhead	Included for every year
Wokingham	Included for every year
Bath and North East Somerset	Excluded: 2022: DfT warning: Avon and Somerset / Staffordshire reporting may be incomplete; 2023: DfT warning: Avon and Somerset / Staffordshire reporting may be incomplete
Bournemouth, Christchurch and Poole	Excluded: 2016: No matching traffic authority code and year; mileage rate withheld; 2017: No matching traffic authority code and year; mileage rate withheld; 2018: No matching traffic authority code and year; mileage rate withheld
Bristol, City of	Excluded: 2022: DfT warning: Avon and Somerset / Staffordshire reporting may be incomplete; 2023: DfT warning: Avon and Somerset / Staffordshire reporting may be incomplete
Cornwall	Included for every year
Devon	Included for every year
Dorset	Excluded: 2016: No matching traffic authority code and year; mileage rate withheld; 2017: No matching traffic authority code and year; mileage rate withheld; 2018: No matching traffic authority code and year; mileage rate withheld
Gloucestershire	Included for every year
Isles of Scilly	Excluded: 2016: Traffic denominator differs by over 0.5% from the official rate; mileage rate withheld; 2017: Traffic denominator differs by over 0.5% from the official rate; mileage rate withheld; 2019: Traffic denominator differs by over 0.5% from the official rate; mileage rate withheld; 2022: Traffic denominator differs by over 0.5% from the official rate; mileage rate withheld; 2023: Traffic denominator differs by over 0.5% from the official rate; mileage rate withheld; 2025: Traffic denominator differs by over 0.5% from the official rate; mileage rate withheld
North Somerset	Excluded: 2022: DfT warning: Avon and Somerset / Staffordshire reporting may be incomplete; 2023: DfT warning: Avon and Somerset / Staffordshire reporting may be incomplete
Plymouth	Included for every year
Somerset	Excluded: 2022: DfT warning: Avon and Somerset / Staffordshire reporting may be incomplete; 2023: DfT warning: Avon and Somerset / Staffordshire reporting may be incomplete
South Gloucestershire	Excluded: 2022: DfT warning: Avon and Somerset / Staffordshire reporting may be incomplete; 2023: DfT warning: Avon and Somerset / Staffordshire reporting may be incomplete
Swindon	Included for every year
Torbay	Included for every year
Wiltshire	Included for every year
Aberdeen City	Included for every year
Aberdeenshire	Included for every year
Angus	Included for every year
Argyll and Bute	Included for every year
City of Edinburgh	Included for every year
Clackmannanshire	Included for every year
Dumfries and Galloway	Included for every year
Dundee City	Included for every year
East Ayrshire	Included for every year
East Dunbartonshire	Included for every year
East Lothian	Included for every year
East Renfrewshire	Included for every year
Falkirk	Included for every year
Fife	Included for every year
Glasgow City	Included for every year
Highland	Included for every year
Inverclyde	Included for every year
Midlothian	Included for every year
Moray	Included for every year
Na h-Eileanan Siar	Included for every year
North Ayrshire	Included for every year
North Lanarkshire	Included for every year
Orkney Islands	Included for every year
Perth and Kinross	Included for every year
Renfrewshire	Included for every year
Scottish Borders	Included for every year
Shetland Islands	Included for every year
South Ayrshire	Included for every year
South Lanarkshire	Included for every year
Stirling	Included for every year
West Dunbartonshire	Included for every year
West Lothian	Included for every year
Blaenau Gwent	Included for every year
Bridgend	Included for every year
Caerphilly	Included for every year
Cardiff	Included for every year
Carmarthenshire	Included for every year
Ceredigion	Included for every year
Conwy	Included for every year
Denbighshire	Included for every year
Flintshire	Included for every year
Gwynedd	Included for every year
Isle of Anglesey	Included for every year
Merthyr Tydfil	Included for every year
Monmouthshire	Included for every year
Neath Port Talbot	Included for every year
Newport	Included for every year
Pembrokeshire	Included for every year
Powys	Included for every year
Rhondda Cynon Taf	Included for every year
Swansea	Included for every year
Torfaen	Included for every year
Vale of Glamorgan	Included for every year
Wrexham	Included for every year

FROM PUBLIC EVIDENCE TO RATING EVIDENCE

The stronger claim needs a controlled test.

The public tracker tests whether geographic outcomes differ and persist. Proving a better insurance rating structure requires the same insurer portfolio, the same non-geographic variables and genuinely held-out claims.

Postcode baseline

Same non-geographic rating variables plus a credibility-weighted postcode effect.

Awaiting insurer study

Decomposed geography

Same other variables plus geographic components, fitted on training data only.

Awaiting insurer study

Combined model

Geographic components plus a residual postcode effect.

Awaiting insurer study

Three demonstrations, with explicit evidence gates

Question	Evidence required	Available here
Same postcode, different risks?	Exposure and outcomes by road segment or geocoded insured location, inside one postcode; credible event counts over multiple years.	Protocol ready. Fine-grained exposure and insurer data not supplied.
Similar outcomes, different components?	Separate exposure, frequency, severity and hazard; discovery-selected comparisons checked in later years.	Authority component profiles, ten-year trends and road-type series.
Different postcodes, similar risk mechanisms?	Match decomposed features without using validation outcomes, then compare later claims with uncertainty.	Public area comparisons available; postcode-level insurance equivalence untested.

Pre-register the insurer validation

Freeze preprocessing, covariates, smoothing and hyperparameters on training data only.
Group repeated policies and claims consistently; isolate temporal and geographic holdouts.
Use comparable non-geographic features and exposure offsets for A, B and C.
Bootstrap policy or spatial clusters; do not treat correlated area-years as independent.
Pre-register a material improvement threshold and failure criteria; retain negative results.
Exclude quote conversion / price elasticity from the pure-risk target.
Document development, inflation, missingness, reporting changes, drift and fairness/proxy review.

Use paired comparisons of A, B and C on held-out policy years, plus a separate geographic holdout. Report calibration, deviance, lift, cluster-bootstrap uncertainty and performance in tail years. The combined model tests whether postcode retains useful residual information.

Download study protocol & data contract

Keep the exposures distinct

Home address, overnight parking, roads driven and incident location answer different questions. Traffic through an area is not resident mileage. The MOT test-station postcode is not a vehicle keeper’s address.

Explore the shared MOT evidence

Separate risk from price

Price elasticity and conversion belong in a separate commercial experiment. Deprivation or fuel poverty does not establish fraud. Behavioural and moral-risk mechanisms need direct, defensible evidence and a proxy/fairness review.

No claims-frequency improvement, monetary severity effect or pricing lift is asserted by this public release.

Sources and periods

RAS0403: collisions and casualties by local authority · 2016–2025 · accessed 2026-09-23 · Archived input

Local authority motor vehicle mileage · 2016–2025 · accessed 2026-09-23 · Archived input

RAS0302: road-type collision and casualty rates · 2016–2025 · accessed 2026-09-23 · Archived input

STATS19 annual releases · Latest available release · accessed 2026-09-23

Road safety table index · Latest available release · accessed 2026-09-23

Resident travel and rural/urban classification · Annual series; 2024 classification break · accessed 2026-09-23

Geography can describe several different mechanisms. The evidence should keep them separate.

Beyond Postcodes · Johan Strydom

Through The Actuary Lens

Authority-level patterns support investigation, but cannot establish within-postcode differences or pricing lift without geocoded insurer exposure and held-out claims.

Method and limitations

Published measures & limits

Study design and validation protocol Geographic sources and reproducibility

Injury collision frequency

Police-reported injury collisions on roads in this area, divided by motor vehicle miles travelled in the same area. Not all insurance claims.

Unit: collisions / 100,000 motor vehicle miles

Serious injury exposure

Killed or seriously injured casualties, adjusted by DfT for reporting changes. Not claim cost or the probability of a claim.

Unit: killed or seriously injured casualties / 100,000 motor vehicle miles

Fatality exposure

People killed, divided by motor vehicle miles. Road casualty outcomes do not establish monetary claim severity.

Unit: fatalities / 100,000 motor vehicle miles

Severity conditional on collision

DfT-adjusted fatal or serious collisions divided by all reported injury collisions. The denominator is collisions, not miles.

Unit: % injury collisions fatal or serious

Traffic through the area

Traffic occurring on roads in the area. This is not the annual mileage of residents or vehicles kept here.

Unit: billion motor vehicle miles

About the five Postcode Risk Indices

These five public-data measures are different from Johan’s proprietary Postcode Risk Indices. The indices await validated definitions and inputs; no index values are published here.

Johan Strydom

Loading approved evidence

Retrieving and verifying the requested analytical release. Result data loads before optional map boundaries and source checks.

Your filters and release stay in the address. Navigation remains available.

POSTCODE RISK LAB

Do geographic differences persist?

Explore road outcomes across authorities and test whether differences recur in later years. These public proxies do not measure postcode-level insurance claims.

Public geographic evidence. Johan’s five proprietary Postcode Risk Indices are not published here. Their definitions and inputs still require validation and approval.

Explore geographic evidence

2016–2025 · Counties and unitary authorities, December 2025

THE ACTUARY LENSGEOGRAPHY · EVIDENCE · PERSISTENCE

Beyond Postcodes — Geo Risk

Unpack geography. Follow the risk. Test whether the differences endure.

Read the white paper

Official sources · 2016–2025207 areas · 2,070 area-yearsPublic evidence, not a validated insurance tariff

Methods & limits · County Durham · Injury collision frequency · Map year 2025 · History 2016–2025 · Assessment 2022–2025

Release and terminology

lens-2026-10-04-59b57c37396f

Fixed-panel benchmark: membership, weighting and limits

Authority	Panel eligibility
County Durham	Included for every year
Darlington	Included for every year
Gateshead	Included for every year
Hartlepool	Included for every year
Middlesbrough	Included for every year
Newcastle upon Tyne	Included for every year
North Tyneside	Included for every year
Northumberland	Included for every year
Redcar and Cleveland	Included for every year
South Tyneside	Included for every year
Stockton-on-Tees	Included for every year
Sunderland	Included for every year
Blackburn with Darwen	Included for every year
Blackpool	Included for every year
Bolton	Included for every year
Bury	Included for every year
Cheshire East	Included for every year
Cheshire West and Chester	Included for every year
Cumberland	Excluded: 2016: No matching traffic authority code and year; mileage rate withheld; 2017: No matching traffic authority code and year; mileage rate withheld; 2018: No matching traffic authority code and year; mileage rate withheld; 2019: No matching traffic authority code and year; mileage rate withheld; 2020: No matching traffic authority code and year; mileage rate withheld; 2021: No matching traffic authority code and year; mileage rate withheld; 2022: No matching traffic authority code and year; mileage rate withheld
Halton	Included for every year
Knowsley	Included for every year
Lancashire	Included for every year
Liverpool	Included for every year
Manchester	Included for every year
Oldham	Included for every year
Rochdale	Included for every year
Salford	Included for every year
Sefton	Included for every year
St. Helens	Included for every year
Stockport	Included for every year
Tameside	Included for every year
Trafford	Included for every year
Warrington	Included for every year
Westmorland and Furness	Excluded: 2016: No matching traffic authority code and year; mileage rate withheld; 2017: No matching traffic authority code and year; mileage rate withheld; 2018: No matching traffic authority code and year; mileage rate withheld; 2019: No matching traffic authority code and year; mileage rate withheld; 2020: No matching traffic authority code and year; mileage rate withheld; 2021: No matching traffic authority code and year; mileage rate withheld; 2022: No matching traffic authority code and year; mileage rate withheld
Wigan	Included for every year
Wirral	Included for every year
Barnsley	Excluded: 2016: No matching traffic authority code and year; mileage rate withheld; 2017: No matching traffic authority code and year; mileage rate withheld; 2018: No matching traffic authority code and year; mileage rate withheld; 2019: No matching traffic authority code and year; mileage rate withheld; 2020: No matching traffic authority code and year; mileage rate withheld; 2021: No matching traffic authority code and year; mileage rate withheld; 2022: No matching traffic authority code and year; mileage rate withheld; 2023: No matching traffic authority code and year; mileage rate withheld; 2024: No matching traffic authority code and year; mileage rate withheld; 2025: No matching traffic authority code and year; mileage rate withheld
Bradford	Included for every year
Calderdale	Included for every year
Doncaster	Included for every year
East Riding of Yorkshire	Included for every year
Kingston upon Hull, City of	Included for every year
Kirklees	Included for every year
Leeds	Included for every year
North East Lincolnshire	Included for every year
North Lincolnshire	Included for every year
North Yorkshire	Included for every year
Rotherham	Included for every year
Sheffield	Excluded: 2016: No matching traffic authority code and year; mileage rate withheld; 2017: No matching traffic authority code and year; mileage rate withheld; 2018: No matching traffic authority code and year; mileage rate withheld; 2019: No matching traffic authority code and year; mileage rate withheld; 2020: No matching traffic authority code and year; mileage rate withheld; 2021: No matching traffic authority code and year; mileage rate withheld; 2022: No matching traffic authority code and year; mileage rate withheld; 2023: No matching traffic authority code and year; mileage rate withheld; 2024: No matching traffic authority code and year; mileage rate withheld; 2025: No matching traffic authority code and year; mileage rate withheld
Wakefield	Included for every year
York	Included for every year
Derby	Included for every year
Derbyshire	Included for every year
Leicester	Included for every year
Leicestershire	Included for every year
Lincolnshire	Included for every year
North Northamptonshire	Excluded: 2016: No matching traffic authority code and year; mileage rate withheld; 2017: No matching traffic authority code and year; mileage rate withheld; 2018: No matching traffic authority code and year; mileage rate withheld; 2019: No matching traffic authority code and year; mileage rate withheld; 2020: No matching traffic authority code and year; mileage rate withheld
Nottingham	Included for every year
Nottinghamshire	Included for every year
Rutland	Included for every year
West Northamptonshire	Excluded: 2016: No matching traffic authority code and year; mileage rate withheld; 2017: No matching traffic authority code and year; mileage rate withheld; 2018: No matching traffic authority code and year; mileage rate withheld; 2019: No matching traffic authority code and year; mileage rate withheld; 2020: No matching traffic authority code and year; mileage rate withheld
Birmingham	Included for every year
Coventry	Included for every year
Dudley	Included for every year
Herefordshire, County of	Included for every year
Sandwell	Included for every year
Shropshire	Included for every year
Solihull	Included for every year
Staffordshire	Excluded: 2022: DfT warning: Avon and Somerset / Staffordshire reporting may be incomplete; 2023: DfT warning: Avon and Somerset / Staffordshire reporting may be incomplete
Stoke-on-Trent	Excluded: 2022: DfT warning: Avon and Somerset / Staffordshire reporting may be incomplete; 2023: DfT warning: Avon and Somerset / Staffordshire reporting may be incomplete
Telford and Wrekin	Included for every year
Walsall	Included for every year
Warwickshire	Included for every year
Wolverhampton	Included for every year
Worcestershire	Included for every year
Bedford	Included for every year
Cambridgeshire	Included for every year
Central Bedfordshire	Included for every year
Essex	Included for every year
Hertfordshire	Included for every year
Luton	Included for every year
Norfolk	Included for every year
Peterborough	Included for every year
Southend-on-Sea	Included for every year
Suffolk	Included for every year
Thurrock	Included for every year
Barking and Dagenham	Included for every year
Barnet	Included for every year
Bexley	Included for every year
Brent	Included for every year
Bromley	Included for every year
Camden	Included for every year
City of London	Included for every year
Croydon	Included for every year
Ealing	Included for every year
Enfield	Included for every year
Greenwich	Included for every year
Hackney	Included for every year
Hammersmith and Fulham	Included for every year
Haringey	Included for every year
Harrow	Included for every year
Havering	Included for every year
Hillingdon	Included for every year
Hounslow	Included for every year
Islington	Included for every year
Kensington and Chelsea	Included for every year
Kingston upon Thames	Included for every year
Lambeth	Included for every year
Lewisham	Included for every year
Merton	Included for every year
Newham	Included for every year
Redbridge	Included for every year
Richmond upon Thames	Included for every year
Southwark	Included for every year
Sutton	Included for every year
Tower Hamlets	Included for every year
Waltham Forest	Included for every year
Wandsworth	Included for every year
Westminster	Included for every year
Bracknell Forest	Included for every year
Brighton and Hove	Included for every year
Buckinghamshire	Excluded: 2016: Official comparison rate unavailable; independent reconciliation not possible; 2017: Official comparison rate unavailable; independent reconciliation not possible; 2018: Official comparison rate unavailable; independent reconciliation not possible; 2019: Official comparison rate unavailable; independent reconciliation not possible; 2020: Official comparison rate unavailable; independent reconciliation not possible; 2021: Official comparison rate unavailable; independent reconciliation not possible; 2022: Official comparison rate unavailable; independent reconciliation not possible; 2023: Official comparison rate unavailable; independent reconciliation not possible; 2024: Official comparison rate unavailable; independent reconciliation not possible; 2025: Official comparison rate unavailable; independent reconciliation not possible
East Sussex	Included for every year
Hampshire	Included for every year
Isle of Wight	Included for every year
Kent	Included for every year
Medway	Included for every year
Milton Keynes	Included for every year
Oxfordshire	Included for every year
Portsmouth	Included for every year
Reading	Included for every year
Slough	Included for every year
Southampton	Included for every year
Surrey	Included for every year
West Berkshire	Included for every year
West Sussex	Included for every year
Windsor and Maidenhead	Included for every year
Wokingham	Included for every year
Bath and North East Somerset	Excluded: 2022: DfT warning: Avon and Somerset / Staffordshire reporting may be incomplete; 2023: DfT warning: Avon and Somerset / Staffordshire reporting may be incomplete
Bournemouth, Christchurch and Poole	Excluded: 2016: No matching traffic authority code and year; mileage rate withheld; 2017: No matching traffic authority code and year; mileage rate withheld; 2018: No matching traffic authority code and year; mileage rate withheld
Bristol, City of	Excluded: 2022: DfT warning: Avon and Somerset / Staffordshire reporting may be incomplete; 2023: DfT warning: Avon and Somerset / Staffordshire reporting may be incomplete
Cornwall	Included for every year
Devon	Included for every year
Dorset	Excluded: 2016: No matching traffic authority code and year; mileage rate withheld; 2017: No matching traffic authority code and year; mileage rate withheld; 2018: No matching traffic authority code and year; mileage rate withheld
Gloucestershire	Included for every year
Isles of Scilly	Excluded: 2016: Traffic denominator differs by over 0.5% from the official rate; mileage rate withheld; 2017: Traffic denominator differs by over 0.5% from the official rate; mileage rate withheld; 2019: Traffic denominator differs by over 0.5% from the official rate; mileage rate withheld; 2022: Traffic denominator differs by over 0.5% from the official rate; mileage rate withheld; 2023: Traffic denominator differs by over 0.5% from the official rate; mileage rate withheld; 2025: Traffic denominator differs by over 0.5% from the official rate; mileage rate withheld
North Somerset	Excluded: 2022: DfT warning: Avon and Somerset / Staffordshire reporting may be incomplete; 2023: DfT warning: Avon and Somerset / Staffordshire reporting may be incomplete
Plymouth	Included for every year
Somerset	Excluded: 2022: DfT warning: Avon and Somerset / Staffordshire reporting may be incomplete; 2023: DfT warning: Avon and Somerset / Staffordshire reporting may be incomplete
South Gloucestershire	Excluded: 2022: DfT warning: Avon and Somerset / Staffordshire reporting may be incomplete; 2023: DfT warning: Avon and Somerset / Staffordshire reporting may be incomplete
Swindon	Included for every year
Torbay	Included for every year
Wiltshire	Included for every year
Aberdeen City	Included for every year
Aberdeenshire	Included for every year
Angus	Included for every year
Argyll and Bute	Included for every year
City of Edinburgh	Included for every year
Clackmannanshire	Included for every year
Dumfries and Galloway	Included for every year
Dundee City	Included for every year
East Ayrshire	Included for every year
East Dunbartonshire	Included for every year
East Lothian	Included for every year
East Renfrewshire	Included for every year
Falkirk	Included for every year
Fife	Included for every year
Glasgow City	Included for every year
Highland	Included for every year
Inverclyde	Included for every year
Midlothian	Included for every year
Moray	Included for every year
Na h-Eileanan Siar	Included for every year
North Ayrshire	Included for every year
North Lanarkshire	Included for every year
Orkney Islands	Included for every year
Perth and Kinross	Included for every year
Renfrewshire	Included for every year
Scottish Borders	Included for every year
Shetland Islands	Included for every year
South Ayrshire	Included for every year
South Lanarkshire	Included for every year
Stirling	Included for every year
West Dunbartonshire	Included for every year
West Lothian	Included for every year
Blaenau Gwent	Included for every year
Bridgend	Included for every year
Caerphilly	Included for every year
Cardiff	Included for every year
Carmarthenshire	Included for every year
Ceredigion	Included for every year
Conwy	Included for every year
Denbighshire	Included for every year
Flintshire	Included for every year
Gwynedd	Included for every year
Isle of Anglesey	Included for every year
Merthyr Tydfil	Included for every year
Monmouthshire	Included for every year
Neath Port Talbot	Included for every year
Newport	Included for every year
Pembrokeshire	Included for every year
Powys	Included for every year
Rhondda Cynon Taf	Included for every year
Swansea	Included for every year
Torfaen	Included for every year
Vale of Glamorgan	Included for every year
Wrexham	Included for every year

FROM PUBLIC EVIDENCE TO RATING EVIDENCE

The stronger claim needs a controlled test.

Postcode baseline

Same non-geographic rating variables plus a credibility-weighted postcode effect.

Awaiting insurer study

Decomposed geography

Same other variables plus geographic components, fitted on training data only.

Awaiting insurer study

Combined model

Geographic components plus a residual postcode effect.

Awaiting insurer study

Three demonstrations, with explicit evidence gates

Question	Evidence required	Available here
Same postcode, different risks?	Exposure and outcomes by road segment or geocoded insured location, inside one postcode; credible event counts over multiple years.	Protocol ready. Fine-grained exposure and insurer data not supplied.
Similar outcomes, different components?	Separate exposure, frequency, severity and hazard; discovery-selected comparisons checked in later years.	Authority component profiles, ten-year trends and road-type series.
Different postcodes, similar risk mechanisms?	Match decomposed features without using validation outcomes, then compare later claims with uncertainty.	Public area comparisons available; postcode-level insurance equivalence untested.

Pre-register the insurer validation

Freeze preprocessing, covariates, smoothing and hyperparameters on training data only.
Group repeated policies and claims consistently; isolate temporal and geographic holdouts.
Use comparable non-geographic features and exposure offsets for A, B and C.
Bootstrap policy or spatial clusters; do not treat correlated area-years as independent.
Pre-register a material improvement threshold and failure criteria; retain negative results.
Exclude quote conversion / price elasticity from the pure-risk target.
Document development, inflation, missingness, reporting changes, drift and fairness/proxy review.

Download study protocol & data contract

Keep the exposures distinct

Explore the shared MOT evidence

Separate risk from price

No claims-frequency improvement, monetary severity effect or pricing lift is asserted by this public release.

Sources and periods

RAS0403: collisions and casualties by local authority · 2016–2025 · accessed 2026-09-23 · Archived input

Local authority motor vehicle mileage · 2016–2025 · accessed 2026-09-23 · Archived input

RAS0302: road-type collision and casualty rates · 2016–2025 · accessed 2026-09-23 · Archived input

STATS19 annual releases · Latest available release · accessed 2026-09-23

Road safety table index · Latest available release · accessed 2026-09-23

Resident travel and rural/urban classification · Annual series; 2024 classification break · accessed 2026-09-23

Geography can describe several different mechanisms. The evidence should keep them separate.

Beyond Postcodes · Johan Strydom

Through The Actuary Lens

Authority-level patterns support investigation, but cannot establish within-postcode differences or pricing lift without geocoded insurer exposure and held-out claims.

Method and limitations

Published measures & limits

Study design and validation protocol Geographic sources and reproducibility

Injury collision frequency

Police-reported injury collisions on roads in this area, divided by motor vehicle miles travelled in the same area. Not all insurance claims.

Unit: collisions / 100,000 motor vehicle miles

Serious injury exposure

Killed or seriously injured casualties, adjusted by DfT for reporting changes. Not claim cost or the probability of a claim.

Unit: killed or seriously injured casualties / 100,000 motor vehicle miles

Fatality exposure

People killed, divided by motor vehicle miles. Road casualty outcomes do not establish monetary claim severity.

Unit: fatalities / 100,000 motor vehicle miles

Severity conditional on collision

DfT-adjusted fatal or serious collisions divided by all reported injury collisions. The denominator is collisions, not miles.

Unit: % injury collisions fatal or serious

Traffic through the area

Traffic occurring on roads in the area. This is not the annual mileage of residents or vehicles kept here.

Unit: billion motor vehicle miles

About the five Postcode Risk Indices

These five public-data measures are different from Johan’s proprietary Postcode Risk Indices. The indices await validated definitions and inputs; no index values are published here.

Source	Evidence period	Source published	Checked in release	Latest check	Monitoring state
RAS0403: collisions and casualties by local authority	2016–2025	Date unavailable	23 Sept 2026	21 Oct 2026	No source issue recorded
Local authority motor vehicle mileage	2016–2025	Date unavailable	23 Sept 2026	21 Oct 2026	No source issue recorded
RAS0302: road-type collision and casualty rates	2016–2025	Date unavailable	23 Sept 2026	21 Oct 2026	No source issue recorded
Counties and Unitary Authorities December 2025 boundaries	December 2025	Date unavailable	23 Sept 2026	23 Sept 2026	Source content changed; review pending
Rainfall — England	2016–2025	Date unavailable	23 Sept 2026	23 Sept 2026	Source content changed; review pending
Rainfall — Wales	2016–2025	Date unavailable	23 Sept 2026	23 Sept 2026	Source content changed; review pending
Rainfall — Scotland	2016–2025	Date unavailable	23 Sept 2026	23 Sept 2026	Source content changed; review pending
Air frost — England	2016–2025	Date unavailable	23 Sept 2026	23 Sept 2026	Source content changed; review pending
Air frost — Wales	2016–2025	Date unavailable	23 Sept 2026	23 Sept 2026	Source content changed; review pending
Air frost — Scotland	2016–2025	Date unavailable	23 Sept 2026	23 Sept 2026	Source content changed; review pending
Wet days ≥1 mm — England	2016–2025	Date unavailable	23 Sept 2026	23 Sept 2026	Source content changed; review pending
Wet days ≥1 mm — Wales	2016–2025	Date unavailable	23 Sept 2026	23 Sept 2026	Source content changed; review pending
Wet days ≥1 mm — Scotland	2016–2025	Date unavailable	23 Sept 2026	23 Sept 2026	Source content changed; review pending
Recorded vehicle offences by police force	Calendar 2016–2025; source updated 23 July 2026	Date unavailable	23 Sept 2026	Date unavailable	No live check linked
Police Force Areas December 2023 boundaries	December 2023	Date unavailable	23 Sept 2026	23 Sept 2026	Source content changed; review pending
Properties in river and sea flood hazard	June 2026	Date unavailable	23 Sept 2026	23 Sept 2026	Source content changed; review pending
Properties in surface-water flood hazard	September 2025	Date unavailable	23 Sept 2026	23 Sept 2026	Source content changed; review pending
STATS19 annual releases	Latest available release	Date unavailable	26 Sept 2026	16 Oct 2026	Source content changed; review pending
Road safety table index	Latest available release	Date unavailable	23 Sept 2026	16 Oct 2026	Source content changed; review pending
Police street-level crime	Monthly releases	Date unavailable	23 Sept 2026	21 Oct 2026	No source issue recorded
River and sea flood hazard	Current hazard model	Date unavailable	23 Sept 2026	23 Sept 2026	Source content changed; review pending
Surface-water flood hazard	Current hazard model	Date unavailable	23 Sept 2026	23 Sept 2026	Source content changed; review pending
Resident travel and rural/urban classification	Annual series; 2024 classification break	Date unavailable	23 Sept 2026	23 Sept 2026	Source content changed; review pending
Anonymised MOT data	Annual releases	Date unavailable	22 Sept 2026	22 Oct 2026	No source issue recorded

Explore geographic evidence

Beyond Postcodes — Geo Risk

The stronger claim needs a controlled test.

Postcode baseline

Decomposed geography

Combined model

Three demonstrations, with explicit evidence gates

Pre-register the insurer validation

Keep the exposures distinct

Separate risk from price

Through The Actuary Lens

Published measures & limits

Injury collision frequency

Serious injury exposure

Fatality exposure

Severity conditional on collision

Traffic through the area

Loading approved evidence

Explore geographic evidence

Beyond Postcodes — Geo Risk

The stronger claim needs a controlled test.

Postcode baseline

Decomposed geography

Combined model

Three demonstrations, with explicit evidence gates

Pre-register the insurer validation

Keep the exposures distinct

Separate risk from price

Through The Actuary Lens

Published measures & limits

Injury collision frequency

Serious injury exposure

Fatality exposure

Severity conditional on collision

Traffic through the area

Sources & release