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CrashStats

HP4 road accidents: crash map and statistics

Collisions since 1979
2,554
1,493rd of 2,813 postcode districts, highest first
Casualties
3,636
1.42 per collision
Fatal collisions
47
52 people killed
Serious collisions
622
753 seriously injured
Collisions in 2025
21
19 in 2024
Casualties in 2025
25
Up 19% on 2024

Road collision statistics for HP4

Collisions by severity, 1979 to 2025

  • Fatal471.8%
  • Serious62224%
  • Slight1,88574%

What the data shows

  • HP4 had 206 collisions from 2016 to 2025, 47% fewer than the 392 from 2006 to 2015.
  • 26% of collisions in HP4 were fatal or serious, against 20% across Great Britain.
  • 358 children under 16 were killed or injured in HP4, 9.9% of the casualties whose age was recorded.
  • The road surface was wet, icy, snowy or flooded in 41% of collisions in HP4.

Where HP4 ranks among 2,813 postcode districts

Most collisions
1,493rd
Most casualties
1,433rd
Most fatal collisions
1,276th
Most serious collisions
1,143rd

Collisions by day of the week

  • Monday345 (14%)
  • Tuesday353 (14%)
  • Wednesday360 (14%)
  • Thursday355 (14%)
  • Friday436 (17%)
  • Saturday389 (15%)
  • Sunday316 (12%)

Light conditions

  • Daylight1,879 (74%)
  • Dark, street lights lit369 (14%)
  • Dark, no street lighting282 (11%)
  • Dark, lighting unknown13 (0.5%)
  • Dark, street lights unlit11 (0.4%)

Type of road

  • Single carriageway2,342 (92%)
  • Dual carriageway147 (5.8%)
  • Roundabout32 (1.3%)
  • One way street or slip road26 (1%)
  • Not recorded7 (0.3%)

Speed limit at the scene

  • 10 mph1 (under 0.1%)
  • 20 mph33 (1.3%)
  • 30 mph1,412 (55%)
  • 40 mph114 (4.5%)
  • 50 mph14 (0.5%)
  • 60 mph831 (33%)
  • 70 mph149 (5.8%)

Weather at the time

  • Fine, no high winds1,990 (78%)
  • Raining, no high winds379 (15%)
  • Fine with high winds31 (1.2%)
  • Fog or mist26 (1%)
  • Raining with high winds26 (1%)
  • Snowing, no high winds14 (0.5%)
  • Snowing with high winds3 (0.1%)
  • Other60 (2.3%)
  • Not recorded25 (1%)

Who was hurt

  • Car occupant2,373 (65%)
  • Motorcyclist424 (12%)
  • Pedestrian387 (11%)
  • Cyclist178 (4.9%)
  • Van occupant111 (3.1%)
  • Goods vehicle occupant (over 3.5 tonnes)51 (1.4%)
  • Bus or coach occupant49 (1.3%)
  • Minibus occupant44 (1.2%)
  • Taxi or private hire car occupant8 (0.2%)
  • Other vehicle occupant5 (0.1%)
  • Other6 (0.2%)

Source: Department for Transport, STATS19 road safety data

HP4 road accidents by year

Collisions and casualties in HP4, 1979 to 2025

Collisions in HP4 peaked at 99 in 1988; 2025 had 21.

  • Collisions
  • Collisions in 2025: 21
  • Casualties

Source: Department for Transport, STATS19 road safety data

View as a table
YearCollisionsCasualties
20252125
20241921
20232327
20221623
20211519
20202329
20192031
20181726
20172431
20162834
20152124
20142940
20133639
20123652
20112943
20105064
20094466
20084775
20074560
20065584
20054150
20045582
20036193
20025277
20016084
200082114
19995986
19986399
199770100
19966695
199564101
19947192
19936685
199274149
19916390
199087114
198994139
198899143
19876797
198675103
198578112
198470112
198395124
198296149
198180107
198085110
197983116

Map of recent crashes in HP4

Map of the 24 most recent crashes in HP4

Use the arrow keys to move the map and the plus and minus keys to zoom.

  • 24 crashes
  • Fatal
  • Serious
  • Slight

Recent road crashes in HP4

The 24 most recent collisions in HP4 happened between 23 August 2024 and 24 November 2025.

Severity

Crashes by road in HP4

The A41 has the most collisions in HP4, 588 of 2,554 (23%), followed by the A4251 (318).

Collisions in HP4 on each road, 1979 to 2025
RankRoadCollisionsCasualtiesFatalSerious
1stA4158881015150
2ndA4251318413461
3rdA41462174171269
4thB4506216328459
5thA416175243644
6thB440162106

Council areas covering HP4

Collisions in HP4 were recorded in 3 council areas. Dacorum has 2,291 of 2,554 (90%).

Collisions in HP4 by council area, 1979 to 2025
RankCouncil areaCollisionsCasualtiesFatalSerious
1stDacorum2,2913,19937544
2ndBuckinghamshire156251344
3rdCentral Bedfordshire100176730

Towns in HP4

Collisions in HP4 were recorded in 2 towns, led by Berkhamsted (1,248) and Potten End (127).