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CrashStats

A411 accidents: crash map and statistics

Police recorded 4,690 collisions on the A411 from 1979 to 2025, with 6,265 casualties. Of those crashes, 46 were fatal and 834 serious, and 47 people were killed.

In 2025 there were 40 collisions on the A411, down 17% from 48 in 2024, with 49 casualties.

Collisions since 1979
4,690
222nd highest of 4,923 roads
Casualties
6,265
1.34 per collision
Fatal collisions
46
47 people killed
Serious collisions
834
961 seriously injured
Collisions in 2025
40
Down 17% on 2024
Casualties in 2025
49
Down 25% on 2024

Crash severity on the A411

On the A411, 1% of collisions were fatal and 18% serious, against 1.6% and 18% across Great Britain.

Collisions by severity, 1979 to 2025

  • Fatal461%
  • Serious83418%
  • Slight3,81081%

Where the A411 ranks among 4,923 roads

Most collisions
222nd
Most casualties
229th
Most fatal collisions
450th
Most serious collisions
229th

A411 accidents by year

Collisions on the A411 peaked at 162 in 1985 and were down to 40 in 2025.

Collisions and casualties on the A411, 1979 to 2025

  • Collisions
  • Collisions in 2025: 40
  • Casualties

Source: Department for Transport, STATS19 road safety data

View as a table
YearCollisionsCasualties
20254049
20244865
20234359
20223849
20214052
20202837
20195258
20184166
20174053
20165574
20156988
20146575
20135867
20127097
201178103
20106685
20095878
200874109
200775101
20067595
200598144
2004115164
200390128
2002114160
2001108142
2000114167
1999140182
1998156227
1997135191
1996125179
1995140195
1994146191
1993135172
1992133177
1991123171
1990128167
1989124149
1988126170
1987142190
1986154209
1985162215
1984156193
1983146185
1982148188
1981140188
1980128171
1979151190

When crashes happen on the A411

Friday has the most collisions on the A411 (772), and 3pm to 6pm is the busiest time of day (1,089).

Collisions by day of the week

  • Monday661 (14%)
  • Tuesday677 (14%)
  • Wednesday686 (15%)
  • Thursday766 (16%)
  • Friday772 (16%)
  • Saturday670 (14%)
  • Sunday458 (9.8%)

Collisions by time of day

  • Midnight to 3am182 (3.9%)
  • 3am to 6am63 (1.3%)
  • 6am to 9am630 (13%)
  • 9am to noon686 (15%)
  • Noon to 3pm879 (19%)
  • 3pm to 6pm1,089 (23%)
  • 6pm to 9pm715 (15%)
  • 9pm to midnight446 (9.5%)

Collisions by month

  • January417 (8.9%)
  • February350 (7.5%)
  • March372 (7.9%)
  • April352 (7.5%)
  • May341 (7.3%)
  • June353 (7.5%)
  • July393 (8.4%)
  • August355 (7.6%)
  • September423 (9%)
  • October430 (9.2%)
  • November496 (11%)
  • December408 (8.7%)

Light conditions at the time

  • Daylight3,305 (70%)
  • Dark, street lights lit1,328 (28%)
  • Dark, lighting unknown32 (0.7%)
  • Dark, street lights unlit16 (0.3%)
  • Dark, no street lighting9 (0.2%)

Source: Department for Transport, STATS19 road safety data

Road and weather conditions in A411 crashes

On the A411, 84% of collisions happened where the speed limit was 30 mph and 65% on a dry road surface.

Speed limit at the scene

  • 20 mph7 (0.1%)
  • 30 mph3,949 (84%)
  • 40 mph544 (12%)
  • 50 mph11 (0.2%)
  • 60 mph156 (3.3%)
  • 70 mph23 (0.5%)

Weather at the time

  • Fine, no high winds3,552 (76%)
  • Raining, no high winds671 (14%)
  • Fine with high winds47 (1%)
  • Raining with high winds37 (0.8%)
  • Other338 (7.2%)
  • Not recorded45 (1%)

Road surface

  • Dry3,031 (65%)
  • Wet or damp1,547 (33%)
  • Frost or ice60 (1.3%)
  • Snow31 (0.7%)
  • Other4 (0.1%)
  • Not recorded17 (0.4%)

Type of road

  • Single carriageway2,999 (64%)
  • One way street or slip road839 (18%)
  • Dual carriageway413 (8.8%)
  • Roundabout278 (5.9%)
  • Not recorded161 (3.4%)

Source: Department for Transport, STATS19 road safety data

People hurt and vehicles involved in A411 crashes

Car occupants make up 61% of the people killed or injured on the A411, followed by motorcyclists (13%).

Casualties by road user

  • Car occupant3,813 (61%)
  • Motorcyclist790 (13%)
  • Pedestrian788 (13%)
  • Cyclist342 (5.5%)
  • Bus or coach occupant276 (4.4%)
  • Van occupant156 (2.5%)
  • Other99 (1.6%)
  • Not recorded1 (under 0.1%)

Vehicles involved

  • Car6,446 (75%)
  • Motorcycle826 (9.6%)
  • Van or goods vehicle up to 3.5 tonnes399 (4.6%)
  • Pedal cycle345 (4%)
  • Bus or coach311 (3.6%)
  • Goods vehicle over 3.5 tonnes144 (1.7%)
  • Other143 (1.7%)
  • Not recorded2 (under 0.1%)

Casualties by age

  • 0 to 596 (1.5%)
  • 6 to 1099 (1.6%)
  • 11 to 15274 (4.4%)
  • 16 to 201,175 (19%)
  • 21 to 25868 (14%)
  • 26 to 351,221 (19%)
  • 36 to 45837 (13%)
  • 46 to 55603 (9.6%)
  • 56 to 65434 (6.9%)
  • 66 to 75286 (4.6%)
  • Over 75199 (3.2%)
  • Not recorded173 (2.8%)

Drivers, passengers and pedestrians

  • Driver or rider3,866 (62%)
  • Passenger1,611 (26%)
  • Pedestrian788 (13%)

Source: Department for Transport, STATS19 road safety data

Map of recent crashes on the A411

Map of the 25 most recent crashes on the A411

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

  • 25 crashes
  • Serious
  • Slight

A411 crashes by council area

Collisions on the A411 were recorded in 5 council areas. Watford has the most, with 2,206, followed by Hertsmere (1,345) and Barnet (1,103).

Collisions on the A411 in each area, 1979 to 2025
RankAreaCollisionsCasualtiesFatalSerious
1stWatford2,2062,97918390
2ndHertsmere1,3451,81516255
3rdBarnet1,1031,42511183
4thThree Rivers263213
5thNorth Hertfordshire3301

A411 crashes by town

Collisions on the A411 were recorded in 5 towns and built-up areas, led by Watford, Watford (2,067) and Barnet (870).

Recent crashes on the A411

These are the 25 most recent collisions on the A411, from 20 May to 27 December 2025.

Severity