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CrashStats

B556 accidents: crash map and statistics

Police recorded 873 collisions on the B556 from 1979 to 2025, with 1,240 casualties. Of those crashes, 9 were fatal and 177 serious, and 9 people were killed.

In 2025 there were 12 collisions on the B556, up 50% from 8 in 2024, with 14 casualties.

Collisions since 1979
873
1,229th highest of 4,923 roads
Casualties
1,240
1.42 per collision
Fatal collisions
9
9 people killed
Serious collisions
177
222 seriously injured
Collisions in 2025
12
Up 50% on 2024
Casualties in 2025
14
Up 27% on 2024

Crash severity on the B556

On the B556, 1% of collisions were fatal and 20% serious, against 1.6% and 18% across Great Britain.

Collisions by severity, 1979 to 2025

  • Fatal91%
  • Serious17720%
  • Slight68779%

Where the B556 ranks among 4,923 roads

Most collisions
1,229th
Most casualties
1,185th
Most fatal collisions
1,807th
Most serious collisions
1,173rd

B556 accidents by year

Collisions on the B556 peaked at 43 in 1990 and were down to 12 in 2025.

Collisions and casualties on the B556, 1979 to 2025

  • Collisions
  • Collisions in 2025: 12
  • Casualties

Source: Department for Transport, STATS19 road safety data

View as a table
YearCollisionsCasualties
20251214
2024811
2023710
2022711
2021913
202068
20191121
20181017
201746
20161722
20151117
20141730
20131216
2012710
20111523
20102132
20091517
20082631
20072133
20061625
20051521
20041931
20033446
20022435
20012843
20003148
19992333
19982231
19973143
19963240
19953049
19943749
19933648
19923245
19913245
19904359
19893748
19883643
198767
198634
1985610
198477
19831113
19821521
19811217
1980719
19791218

When crashes happen on the B556

Thursday has the most collisions on the B556 (149), and 3pm to 6pm is the busiest time of day (206).

Collisions by day of the week

  • Monday133 (15%)
  • Tuesday135 (15%)
  • Wednesday119 (14%)
  • Thursday149 (17%)
  • Friday144 (16%)
  • Saturday108 (12%)
  • Sunday85 (9.7%)

Collisions by time of day

  • Midnight to 3am27 (3.1%)
  • 3am to 6am13 (1.5%)
  • 6am to 9am124 (14%)
  • 9am to noon135 (15%)
  • Noon to 3pm161 (18%)
  • 3pm to 6pm206 (24%)
  • 6pm to 9pm137 (16%)
  • 9pm to midnight70 (8%)

Collisions by month

  • January71 (8.1%)
  • February76 (8.7%)
  • March63 (7.2%)
  • April68 (7.8%)
  • May67 (7.7%)
  • June65 (7.4%)
  • July78 (8.9%)
  • August71 (8.1%)
  • September76 (8.7%)
  • October79 (9%)
  • November83 (9.5%)
  • December76 (8.7%)

Light conditions at the time

  • Daylight640 (73%)
  • Dark, street lights lit171 (20%)
  • Dark, no street lighting51 (5.8%)
  • Dark, lighting unknown8 (0.9%)
  • Dark, street lights unlit3 (0.3%)

Source: Department for Transport, STATS19 road safety data

Road and weather conditions in B556 crashes

On the B556, 59% of collisions happened where the speed limit was 30 mph and 61% on a dry road surface.

Speed limit at the scene

  • 20 mph3 (0.3%)
  • 30 mph514 (59%)
  • 40 mph58 (6.6%)
  • 50 mph3 (0.3%)
  • 60 mph283 (32%)
  • 70 mph12 (1.4%)

Weather at the time

  • Fine, no high winds685 (78%)
  • Raining, no high winds129 (15%)
  • Raining with high winds10 (1.1%)
  • Fine with high winds9 (1%)
  • Other33 (3.8%)
  • Not recorded7 (0.8%)

Road surface

  • Dry529 (61%)
  • Wet or damp315 (36%)
  • Frost or ice19 (2.2%)
  • Flood over 3cm deep4 (0.5%)
  • Other5 (0.6%)
  • Not recorded1 (0.1%)

Type of road

  • Single carriageway785 (90%)
  • Roundabout57 (6.5%)
  • Dual carriageway19 (2.2%)
  • One way street or slip road1 (0.1%)
  • Not recorded11 (1.3%)

Source: Department for Transport, STATS19 road safety data

People hurt and vehicles involved in B556 crashes

Car occupants make up 71% of the people killed or injured on the B556, followed by motorcyclists (9.4%).

Casualties by road user

  • Car occupant886 (71%)
  • Motorcyclist117 (9.4%)
  • Pedestrian84 (6.8%)
  • Cyclist56 (4.5%)
  • Van occupant47 (3.8%)
  • Bus or coach occupant20 (1.6%)
  • Other28 (2.3%)
  • Not recorded2 (0.2%)

Vehicles involved

  • Car1,290 (77%)
  • Motorcycle115 (6.9%)
  • Van or goods vehicle up to 3.5 tonnes87 (5.2%)
  • Goods vehicle over 3.5 tonnes73 (4.4%)
  • Pedal cycle58 (3.5%)
  • Bus or coach23 (1.4%)
  • Other29 (1.7%)
  • Not recorded2 (0.1%)

Casualties by age

  • 0 to 520 (1.6%)
  • 6 to 1023 (1.9%)
  • 11 to 1553 (4.3%)
  • 16 to 20198 (16%)
  • 21 to 25186 (15%)
  • 26 to 35246 (20%)
  • 36 to 45178 (14%)
  • 46 to 55131 (11%)
  • 56 to 6574 (6%)
  • 66 to 7558 (4.7%)
  • Over 7539 (3.1%)
  • Not recorded34 (2.7%)

Drivers, passengers and pedestrians

  • Driver or rider832 (67%)
  • Passenger324 (26%)
  • Pedestrian84 (6.8%)

Source: Department for Transport, STATS19 road safety data

Map of recent crashes on the B556

Map of the 25 most recent crashes on the B556

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

  • 25 crashes
  • Serious
  • Slight

B556 crashes by council area

Collisions on the B556 were recorded in 2 council areas. Hertsmere has the most, with 695, followed by St Albans (169).

Collisions on the B556 in each area, 1979 to 2025
RankAreaCollisionsCasualtiesFatalSerious
1stHertsmere6959816143
2ndSt Albans169247332

B556 crashes by town

Collisions on the B556 were recorded in 3 towns and built-up areas, led by Potters Bar (335) and London Colney (20).

Recent crashes on the B556

These are the 25 most recent collisions on the B556, from 4 August 2023 to 26 November 2025.

Severity