The roads get more dangerous in the dark. By how much depends on where you live.
Every collision record carries the light level and the road surface at the time. Almost nobody publishes what that says about individual places — so here it is, for every British highway authority.
The short version
Across Britain, 28.7% of road collisions happen in the dark, and 6.3% happen in darkness on roads with no working street lighting. 1.4% happen on snow or ice — a small share nationally, but one that is concentrated in particular places and particular weeks.
The seasonal effect is real but uneven. Nationally, collisions from November to January run -4.5% against May to July. The place where darkness accounts for the largest share is Tower Hamlets (37.7%), and the biggest winter swing is in Aberdeen City.
Darkness and ice, authority by authority
Shares are of collisions where the condition was actually recorded — STATS19 marks unknowns separately, and counting those as daylight would understate darkness everywhere.
| Authority | In darkness | Dark, unlit | Snow or ice | Nov–Jan vs May–Jul |
|---|---|---|---|---|
| Tower Hamlets | 37.7% | 1.2% | 0.2% | -3.7% |
| Newham | 35.7% | 1.2% | 0.5% | -6.3% |
| Aberdeen City | 35.4% | 3.6% | 2.2% | +46.5% |
| Birmingham | 34.9% | 1.4% | 0.8% | +7% |
| Westminster | 34.7% | 0.8% | 0.2% | -14.8% |
| Rochdale | 34.7% | 3.6% | 1.1% | +20.7% |
| Glasgow City | 34.2% | 2.3% | 1.5% | +21.7% |
| Manchester | 34% | 1.4% | 0.7% | +6.3% |
| Leicester | 34% | 0.8% | 1.4% | -2% |
| Waltham Forest | 33.9% | 0.6% | 0.4% | -14% |
| Hackney | 33.7% | 0.9% | 0.2% | -23.9% |
| Sandwell | 33.4% | 1.2% | 0.7% | +6.1% |
| Bradford | 33.3% | 3% | 1.7% | +0.3% |
| Hillingdon | 33.3% | 1.6% | 1.2% | +5.3% |
| Greenwich | 33.2% | 1.4% | 0.5% | -1.8% |
| Salford | 33.2% | 1.6% | 0.4% | +15.9% |
| Southwark | 33.1% | 1.1% | 0.2% | -20.8% |
| Barking and Dagenham | 33.1% | 1% | 0.4% | +1.3% |
| Newport | 33.1% | 6.8% | 1.3% | +16.4% |
| Brent | 32.9% | 1.1% | 0.7% | -14.6% |
| Calderdale | 32.5% | 3.5% | 2.5% | -0.7% |
| Redbridge | 32.3% | 1.4% | 0.5% | -11.4% |
| Luton | 32.2% | 1.9% | 0.6% | -4.4% |
| Southampton | 32.1% | 0.9% | 0.9% | +10.7% |
| Haringey | 32.1% | 0.9% | 0.4% | -12.5% |
| Enfield | 32.1% | 1.2% | 0.5% | -7.7% |
| Lambeth | 32% | 0.8% | 0.3% | -18.3% |
| Lewisham | 31.9% | 0.9% | 0.5% | -9.4% |
| Blaenau Gwent | 31.9% | 7.2% | 4.8% | +12.8% |
| Ealing | 31.7% | 1.2% | 0.4% | -21.3% |
| Bexley | 31.7% | 2.3% | 0.8% | -4.9% |
| Bristol, City of | 31.5% | 0.9% | 0.6% | -5.6% |
| Oldham | 31.5% | 1.4% | 1% | +6.9% |
| Wigan | 31.4% | 2.8% | 1.2% | +24.9% |
| Harrow | 31.2% | 0.8% | 0.8% | -4.7% |
| Rotherham | 31.2% | 6.4% | 1.4% | +3% |
| Barnet | 31.1% | 1.3% | 0.5% | +0.5% |
| Islington | 31% | 0.4% | 0.3% | -18.1% |
| Camden | 30.9% | 0.7% | 0.4% | -12.1% |
| Hounslow | 30.9% | 0.9% | 0.6% | -16.8% |
| Leeds | 30.9% | 3.7% | 1.6% | -4.2% |
| Dudley | 30.8% | 1.3% | 1.2% | -4.8% |
| Swansea | 30.8% | 6.2% | 1% | -13.5% |
| Renfrewshire | 30.7% | 5.6% | 2.9% | +20% |
| Bolton | 30.6% | 2.8% | 0.7% | +5.7% |
| Dundee City | 30.5% | 1.7% | 0.7% | +3.8% |
| Kirklees | 30.5% | 3.4% | 2% | +6% |
| Leicestershire | 30.4% | 10.4% | 2.1% | -1.2% |
| Portsmouth | 30.3% | 1.8% | 0.4% | -5.2% |
| North Lincolnshire | 30.1% | 11.4% | 3.7% | +5.9% |
| South Lanarkshire | 30.1% | 9.4% | 3.5% | -3.1% |
| Kensington and Chelsea | 30% | 0.9% | 0.2% | -7.6% |
| Hammersmith and Fulham | 30% | 1.3% | 0.4% | -9.4% |
| West Dunbartonshire | 29.9% | 9.1% | 0.6% | +19.4% |
| Cardiff | 29.9% | 3.1% | 1% | +2.5% |
| Reading | 29.8% | 0.9% | 0.8% | 0% |
| Croydon | 29.8% | 1.3% | 0.8% | +10% |
| Hartlepool | 29.8% | 3.9% | 1.2% | +16.7% |
| Thurrock | 29.7% | 5.1% | 0.5% | +1.5% |
| Havering | 29.6% | 2.3% | 1% | +1% |
| West Northamptonshire | 29.6% | 10% | 2.2% | +2.2% |
| Bromley | 29.5% | 2.1% | 0.7% | +3.1% |
| Rhondda Cynon Taf | 29.5% | 9.9% | 1.1% | -15.2% |
| Blackpool | 29.4% | 1% | 1.1% | +12.3% |
| Warrington | 29.4% | 4.2% | 1.8% | +13.6% |
| Coventry | 29.3% | 2% | 1.2% | +3.6% |
| Brighton and Hove | 29.2% | 2.3% | 0.6% | -13.9% |
| North East Lincolnshire | 29.2% | 3% | 1.5% | -1.5% |
| Liverpool | 29% | 1.1% | 0.8% | +0.6% |
| Surrey | 29% | 9% | 1.9% | -2.4% |
| Swindon | 29% | 6% | 1.4% | +10.5% |
| Blackburn with Darwen | 28.9% | 5.6% | 2.7% | -4.2% |
| Wakefield | 28.9% | 4.2% | 1.5% | -4.3% |
| Ceredigion | 28.7% | 22% | 2.1% | -11.4% |
| Staffordshire | 28.7% | 9.1% | 2.1% | +5.5% |
| North Northamptonshire | 28.6% | 9.4% | 1.9% | +3.5% |
| North Lanarkshire | 28.6% | 5.9% | 1.8% | -7.4% |
| Solihull | 28.6% | 3.6% | 2.4% | -1% |
| Kingston upon Hull, City of | 28.4% | 1% | 0.8% | -7% |
| Nottingham | 28.4% | 0.7% | 1.3% | -2.6% |
| Bath and North East Somerset | 28.4% | 7.5% | 1.7% | -0.8% |
| Wolverhampton | 28.4% | 0.8% | 1.6% | +0.3% |
| Lancashire | 28.4% | 7.9% | 2% | -5% |
| Central Bedfordshire | 28.4% | 10.4% | 1.6% | +4.4% |
| Tameside | 28.3% | 2.3% | 0.5% | -7.6% |
| West Sussex | 28.2% | 11.5% | 1.7% | -8.9% |
| West Lothian | 28.2% | 13.2% | 3.2% | -18% |
| Cumberland | 28.1% | 12% | 2.4% | +1.6% |
| Plymouth | 28.1% | 2.7% | 0.6% | +12.4% |
| Torfaen | 28% | 4.7% | 1.2% | -26.6% |
| Walsall | 28% | 1.3% | 1% | -9.8% |
| Angus | 28% | 17.9% | 2.9% | +17.5% |
| Isle of Wight | 27.9% | 11.7% | 1.9% | -2.2% |
| Merton | 27.9% | 0.5% | 0.6% | +4.2% |
| Sutton | 27.9% | 1.4% | 0.6% | -9.6% |
| Buckinghamshire | 27.9% | 9.7% | 1.9% | +2.4% |
| Stockport | 27.9% | 1.2% | 1% | +7.5% |
| Stoke-on-Trent | 27.8% | 1% | 1.1% | +11.3% |
| Dumfries and Galloway | 27.8% | 21.5% | 2% | -11.4% |
| Hampshire | 27.8% | 10.7% | 1.5% | -4.5% |
| Oxfordshire | 27.7% | 11.2% | 1.5% | +3.2% |
| South Ayrshire | 27.6% | 12.4% | 1.8% | -30% |
| Kent | 27.6% | 8.7% | 1.7% | -4.4% |
| Essex | 27.5% | 9.6% | 1.6% | -0.9% |
| County Durham | 27.5% | 7% | 2% | +21.5% |
| Wandsworth | 27.3% | 0.6% | 0.3% | -23.3% |
| Newcastle upon Tyne | 27.3% | 1.5% | 0.7% | -0.6% |
| Gloucestershire | 27.3% | 12.6% | 1.4% | -7.2% |
| Middlesbrough | 27.3% | 0.8% | 1% | -18% |
| Milton Keynes | 27.3% | 2.9% | 0.9% | +14.2% |
| Lincolnshire | 27.2% | 14.8% | 2.5% | +4% |
| Carmarthenshire | 27.2% | 12.9% | 1% | -2.4% |
| Trafford | 27.2% | 1.4% | 0.4% | +40% |
| Warwickshire | 27.2% | 12% | 1.5% | +1.7% |
| Moray | 27.1% | 18.8% | 2.3% | -40.5% |
| Darlington | 27% | 4.7% | 1.7% | +22.4% |
| City of Edinburgh | 27% | 3% | 1% | +0.8% |
| Bury | 27% | 1.6% | 0.9% | +2.3% |
| Falkirk | 27% | 10% | 2.1% | +5.1% |
| Torbay | 26.9% | 2.5% | 0.6% | +12.3% |
| Knowsley | 26.9% | 4% | 0.7% | +9.2% |
| North Somerset | 26.9% | 8.1% | 1.4% | -19.1% |
| Shropshire | 26.9% | 15.3% | 2.5% | -6.9% |
| Worcestershire | 26.9% | 10.5% | 1.7% | -0.8% |
| Slough | 26.8% | 1% | 1.5% | +11.2% |
| East Lothian | 26.8% | 14.6% | 2.4% | -14.8% |
| Peterborough | 26.7% | 4.6% | 1.7% | +21.4% |
| Powys | 26.6% | 20.1% | 3.4% | -25.7% |
| East Sussex | 26.6% | 11.6% | 1.7% | -3% |
| Wrexham | 26.6% | 10.4% | 2.4% | -1.1% |
| South Gloucestershire | 26.6% | 5.8% | 1.5% | -5.2% |
| Hertfordshire | 26.6% | 5.2% | 1.1% | -2.3% |
| Southend-on-Sea | 26.5% | 0.6% | 0.6% | +0.9% |
| Suffolk | 26.5% | 11.4% | 1.6% | -4.7% |
| Fife | 26.5% | 12.4% | 1.5% | -13.9% |
| St. Helens | 26.4% | 2.1% | 1.4% | -4.3% |
| Pembrokeshire | 26.3% | 16.2% | 1.1% | -33.7% |
| Herefordshire, County of | 26.3% | 17.7% | 2.3% | -3.9% |
| Halton | 26.3% | 3.9% | 2.7% | -2.7% |
| Caerphilly | 26.2% | 7.4% | 1.8% | +1.7% |
| East Renfrewshire | 26.2% | 6.4% | 2.1% | +8.5% |
| Derbyshire | 26.1% | 9.7% | 2.8% | -8.6% |
| Cambridgeshire | 26.1% | 10.5% | 2.1% | -0.7% |
| North Ayrshire | 26% | 10.2% | 0.8% | -1.4% |
| Cheshire East | 26% | 10.6% | 2.3% | -14.7% |
| Bedford | 25.8% | 4.7% | 0.8% | +3.5% |
| Wiltshire | 25.7% | 14.5% | 2.2% | -3.5% |
| Kingston upon Thames | 25.6% | 0.7% | 0.7% | -17.9% |
| East Riding of Yorkshire | 25.5% | 13.3% | 2.2% | -4.9% |
| Monmouthshire | 25.5% | 15.3% | 1.3% | -27.8% |
| Gateshead | 25.5% | 2.4% | 1.4% | +27.5% |
| Bournemouth, Christchurch and Poole | 25.4% | 1.3% | 0.5% | -8.5% |
| Sunderland | 25.3% | 2.7% | 0.9% | +7.5% |
| Doncaster | 25.3% | 6.7% | 1.6% | -3.9% |
| Midlothian | 25.2% | 12.6% | 2.4% | -1.8% |
| Nottinghamshire | 25.1% | 6.6% | 2.1% | +3.4% |
| Norfolk | 25% | 11.8% | 2.1% | -5.6% |
| Scottish Borders | 25% | 20.5% | 3.7% | -20.7% |
| Stockton-on-Tees | 25% | 2.4% | 0.8% | +3.9% |
| Cornwall | 24.9% | 15% | 1.6% | -18.5% |
| York | 24.8% | 4.5% | 1.1% | -5.1% |
| Wirral | 24.8% | 3.1% | 0.8% | +4.6% |
| Devon | 24.8% | 14% | 2.5% | -11.9% |
| Flintshire | 24.8% | 9.7% | 2.4% | -20.2% |
| Medway | 24.7% | 1.9% | 0.4% | -15.3% |
| Dorset | 24.7% | 14.8% | 3% | -16.8% |
| East Ayrshire | 24.7% | 12.7% | 2.7% | -31.6% |
| Derby | 24.6% | 0.7% | 1.8% | +1.2% |
| West Berkshire | 24.4% | 13.3% | 2.1% | -0.6% |
| Somerset | 24.4% | 12.6% | 2.1% | -7.1% |
| Windsor and Maidenhead | 24.4% | 4.9% | 0.8% | -8.9% |
| Neath Port Talbot | 24.1% | 7% | 0.9% | -14.3% |
| Stirling | 24% | 16% | 1.9% | +4.6% |
| Telford and Wrekin | 23.9% | 2.6% | 1.7% | +21.6% |
| Sefton | 23.8% | 2.3% | 1.1% | -5.3% |
| Argyll and Bute | 23.6% | 15.8% | 2.1% | -41.1% |
| Cheshire West and Chester | 23.6% | 8.1% | 1.9% | -11.3% |
| Richmond upon Thames | 23.5% | 0.9% | 1.1% | -25.6% |
| Gwynedd | 23.4% | 12.2% | 0.9% | -46.5% |
| Westmorland and Furness | 23.3% | 14.7% | 3.2% | -28.5% |
| Northumberland | 23.3% | 10.6% | 2.1% | -2.9% |
| Bracknell Forest | 23.1% | 4.8% | 0.9% | -30.5% |
| Wokingham | 23.1% | 4.4% | 1.9% | +15.1% |
| Conwy | 22.8% | 6.6% | 0.3% | -28.6% |
| Perth and Kinross | 22.5% | 14.5% | 3.8% | -28.1% |
| North Yorkshire | 22.4% | 12.7% | 2.2% | -20.2% |
| Redcar and Cleveland | 22.3% | 4.6% | 1.1% | -37.4% |
| Highland | 21.9% | 16.7% | 5.4% | -38.6% |
| North Tyneside | 21.6% | 2.9% | 1.7% | -10.8% |
| Aberdeenshire | 20.5% | 15% | 5% | -31.7% |
| Denbighshire | 20.2% | 10.6% | 2.8% | -39.4% |
| South Tyneside | 18.8% | 1.7% | 0.6% | +1.7% |
Three things this data actually shows
Darkness is not the same risk everywhere
A high darkness share is not simply a matter of latitude. It reflects how much travel happens after dark, how well lit the network is, and what kind of roads carry the traffic. An authority where 37.7% of collisions happen in the dark has a different problem from one at half that, and it responds to different things — lighting and crossings rather than speed management.
Unlit darkness is the sharper measure
Collisions in darkness on a lit road and collisions in darkness with no lighting at all are recorded separately, and the second is the one worth acting on. Nationally it is 6.3% of collisions. Where that figure is high, the question for a highway authority is whether the lighting was ever there, or whether it was switched off.
Ice is rare but not evenly rare
Snow and ice appear in 1.4% of collisions nationally, which sounds negligible until you look at where they concentrate. Highland records 5.4%. Ice collisions also cluster into a handful of days, so a low annual share can still mean a severe week.
What this does not tell you
- •A share is not a rate. A high darkness share means darkness accounts for more of that area’s collisions — not that its roads are more dangerous overall. Read it alongside the casualties per mile driven figure.
- •Condition is recorded, not tested. The officer records the surface and light level at the scene. It is an observation, not a measurement, and it is not a finding that the condition caused the collision.
- •Exposure is not controlled for. Fewer people travel at 3am than at 3pm, so a collision in darkness is drawn from a smaller pool of journeys. Without hourly traffic counts, these shares describe when collisions happen rather than how risky an hour is.
- •Seasonal comparison is coarse. November to January against May to July captures the light difference, but also weather, school terms and traffic volume. It is a signal to investigate, not an explanation.
Source: DfT STATS19 road safety data, Open Government Licence v3, three-year window to 2025. Compiled and reviewed by Stephen Hall, Data lead, Swift Assist. Method and limitations above and on our methodology page.
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