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CrashStats

A409 accidents: crash map and statistics

Police recorded 2,927 collisions on the A409 from 1979 to 2025, with 3,615 casualties. Of those crashes, 24 were fatal and 468 serious, and 25 people were killed.

In 2025 there were 39 collisions on the A409, up 34% from 29 in 2024, with 44 casualties.

Collisions since 1979
2,927
397th highest of 4,923 roads
Casualties
3,615
1.24 per collision
Fatal collisions
24
25 people killed
Serious collisions
468
533 seriously injured
Collisions in 2025
39
Up 34% on 2024
Casualties in 2025
44
Up 33% on 2024

Crash severity on the A409

On the A409, 0.8% of collisions were fatal and 16% serious, against 1.6% and 18% across Great Britain.

Collisions by severity, 1979 to 2025

  • Fatal240.8%
  • Serious46816%
  • Slight2,43583%

Where the A409 ranks among 4,923 roads

Most collisions
397th
Most casualties
434th
Most fatal collisions
836th
Most serious collisions
458th

A409 accidents by year

Collisions on the A409 peaked at 121 in 1979 and were down to 39 in 2025.

Collisions and casualties on the A409, 1979 to 2025

  • Collisions
  • Collisions in 2025: 39
  • Casualties

Source: Department for Transport, STATS19 road safety data

View as a table
YearCollisionsCasualties
20253944
20242933
20233538
20223643
20214048
20202732
20193846
20183447
20173639
20162833
20153348
20145565
20134353
20124851
20114246
20103851
20093753
20083550
20074361
20064149
20054865
20046879
20036479
20025366
20016681
20005574
199976102
19985970
19977198
199681109
19957292
199491114
19936885
19927683
19916676
199084105
198998128
198894109
198786108
19868692
198589104
198493111
198396112
1982114144
198197125
198098114
1979121160

When crashes happen on the A409

Friday has the most collisions on the A409 (468), and 3pm to 6pm is the busiest time of day (638).

Collisions by day of the week

  • Monday430 (15%)
  • Tuesday443 (15%)
  • Wednesday376 (13%)
  • Thursday452 (15%)
  • Friday468 (16%)
  • Saturday445 (15%)
  • Sunday313 (11%)

Collisions by time of day

  • Midnight to 3am152 (5.2%)
  • 3am to 6am48 (1.6%)
  • 6am to 9am264 (9%)
  • 9am to noon438 (15%)
  • Noon to 3pm539 (18%)
  • 3pm to 6pm638 (22%)
  • 6pm to 9pm487 (17%)
  • 9pm to midnight361 (12%)

Collisions by month

  • January226 (7.7%)
  • February205 (7%)
  • March253 (8.6%)
  • April249 (8.5%)
  • May228 (7.8%)
  • June221 (7.6%)
  • July259 (8.8%)
  • August246 (8.4%)
  • September264 (9%)
  • October266 (9.1%)
  • November262 (9%)
  • December248 (8.5%)

Light conditions at the time

  • Daylight1,958 (67%)
  • Dark, street lights lit931 (32%)
  • Dark, lighting unknown26 (0.9%)
  • Dark, street lights unlit10 (0.3%)
  • Dark, no street lighting2 (0.1%)

Source: Department for Transport, STATS19 road safety data

Road and weather conditions in A409 crashes

On the A409, 95% of collisions happened where the speed limit was 30 mph and 73% on a dry road surface.

Speed limit at the scene

  • 10 mph1 (under 0.1%)
  • 20 mph39 (1.3%)
  • 30 mph2,794 (95%)
  • 40 mph91 (3.1%)
  • 50 mph1 (under 0.1%)
  • 60 mph1 (under 0.1%)

Weather at the time

  • Fine, no high winds2,158 (74%)
  • Raining, no high winds376 (13%)
  • Fine with high winds23 (0.8%)
  • Raining with high winds16 (0.5%)
  • Other321 (11%)
  • Not recorded33 (1.1%)

Road surface

  • Dry2,148 (73%)
  • Wet or damp733 (25%)
  • Frost or ice20 (0.7%)
  • Snow11 (0.4%)
  • Other2 (0.1%)
  • Not recorded13 (0.4%)

Type of road

  • Single carriageway2,203 (75%)
  • Dual carriageway233 (8%)
  • One way street or slip road121 (4.1%)
  • Roundabout99 (3.4%)
  • Not recorded271 (9.3%)

Source: Department for Transport, STATS19 road safety data

People hurt and vehicles involved in A409 crashes

Car occupants make up 50% of the people killed or injured on the A409, followed by pedestrians (21%).

Casualties by road user

  • Car occupant1,801 (50%)
  • Pedestrian761 (21%)
  • Motorcyclist484 (13%)
  • Bus or coach occupant273 (7.6%)
  • Cyclist198 (5.5%)
  • Van occupant68 (1.9%)
  • Other29 (0.8%)
  • Not recorded1 (under 0.1%)

Vehicles involved

  • Car3,486 (71%)
  • Motorcycle527 (11%)
  • Bus or coach328 (6.7%)
  • Van or goods vehicle up to 3.5 tonnes244 (5%)
  • Pedal cycle209 (4.2%)
  • Goods vehicle over 3.5 tonnes68 (1.4%)
  • Taxi or private hire car31 (0.6%)
  • Other31 (0.6%)

Casualties by age

  • 0 to 561 (1.7%)
  • 6 to 1093 (2.6%)
  • 11 to 15176 (4.9%)
  • 16 to 20586 (16%)
  • 21 to 25512 (14%)
  • 26 to 35659 (18%)
  • 36 to 45455 (13%)
  • 46 to 55296 (8.2%)
  • 56 to 65253 (7%)
  • 66 to 75173 (4.8%)
  • Over 75130 (3.6%)
  • Not recorded221 (6.1%)

Drivers, passengers and pedestrians

  • Driver or rider1,919 (53%)
  • Passenger935 (26%)
  • Pedestrian761 (21%)

Source: Department for Transport, STATS19 road safety data

Map of recent crashes on the A409

Map of the 25 most recent crashes on the A409

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

  • 25 crashes
  • Serious
  • Slight

A409 crashes by council area

Collisions on the A409 were recorded in 3 council areas. Harrow has the most, with 2,812, followed by Hertsmere (69) and Brent (42).

Collisions on the A409 in each area, 1979 to 2025
RankAreaCollisionsCasualtiesFatalSerious
1stHarrow2,8123,47324452
2ndHertsmere698408
3rdBrent425206

A409 crashes by town

Collisions on the A409 were recorded in 2 towns and built-up areas, led by Harrow (2,287) and Bushey (86).

Recent crashes on the A409

These are the 25 most recent collisions on the A409, from 29 May to 11 December 2025.

Severity