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CrashStats

B4505 accidents: crash map and statistics

Police recorded 508 collisions on the B4505 from 1979 to 2025, with 729 casualties. Of those crashes, 10 were fatal and 119 serious, and 10 people were killed.

In 2025 there were 2 collisions on the B4505, down 50% from 4 in 2024, with 2 casualties.

Collisions since 1979
508
1,943rd highest of 4,923 roads
Casualties
729
1.44 per collision
Fatal collisions
10
10 people killed
Serious collisions
119
140 seriously injured
Collisions in 2025
2
Down 50% on 2024
Casualties in 2025
2
Down 67% on 2024

Crash severity on the B4505

On the B4505, 2% of collisions were fatal and 23% serious, against 1.6% and 18% across Great Britain.

Collisions by severity, 1979 to 2025

  • Fatal102%
  • Serious11923%
  • Slight37975%

Where the B4505 ranks among 4,923 roads

Most collisions
1,943rd
Most casualties
1,860th
Most fatal collisions
1,701st
Most serious collisions
1,660th

B4505 accidents by year

Collisions on the B4505 peaked at 27 in 1990 and were down to 2 in 2025.

Collisions and casualties on the B4505, 1979 to 2025

  • Collisions
  • Collisions in 2025: 2
  • Casualties

Source: Department for Transport, STATS19 road safety data

View as a table
YearCollisionsCasualties
202522
202446
202311
202234
202146
202044
201946
201846
201711
201611
201569
201444
201333
201257
201157
2010713
200956
200879
2007711
20061520
200545
2004912
2003911
2002913
20011415
20001732
19991523
19981214
19971521
19962037
19951320
19941421
19931924
19921824
19911621
19902744
19892336
19881823
19871013
19862434
19851824
19841629
19831523
19821721
19811120
19801928
19791415

When crashes happen on the B4505

Saturday has the most collisions on the B4505 (94), and noon to 3pm is the busiest time of day (97).

Collisions by day of the week

  • Monday75 (15%)
  • Tuesday78 (15%)
  • Wednesday59 (12%)
  • Thursday68 (13%)
  • Friday86 (17%)
  • Saturday94 (19%)
  • Sunday48 (9.4%)

Collisions by time of day

  • Midnight to 3am26 (5.1%)
  • 3am to 6am8 (1.6%)
  • 6am to 9am82 (16%)
  • 9am to noon69 (14%)
  • Noon to 3pm97 (19%)
  • 3pm to 6pm93 (18%)
  • 6pm to 9pm75 (15%)
  • 9pm to midnight58 (11%)

Collisions by month

  • January47 (9.3%)
  • February42 (8.3%)
  • March36 (7.1%)
  • April46 (9.1%)
  • May28 (5.5%)
  • June42 (8.3%)
  • July39 (7.7%)
  • August39 (7.7%)
  • September39 (7.7%)
  • October44 (8.7%)
  • November48 (9.4%)
  • December58 (11%)

Light conditions at the time

  • Daylight346 (68%)
  • Dark, no street lighting91 (18%)
  • Dark, street lights lit63 (12%)
  • Dark, lighting unknown6 (1.2%)
  • Dark, street lights unlit2 (0.4%)

Source: Department for Transport, STATS19 road safety data

Road and weather conditions in B4505 crashes

On the B4505, 45% of collisions happened where the speed limit was 60 mph and 50% on a dry road surface.

Speed limit at the scene

  • 30 mph195 (38%)
  • 40 mph70 (14%)
  • 50 mph10 (2%)
  • 60 mph230 (45%)
  • 70 mph2 (0.4%)
  • Not recorded1 (0.2%)

Weather at the time

  • Fine, no high winds369 (73%)
  • Raining, no high winds91 (18%)
  • Raining with high winds10 (2%)
  • Fine with high winds9 (1.8%)
  • Other27 (5.3%)
  • Not recorded2 (0.4%)

Road surface

  • Dry254 (50%)
  • Wet or damp221 (44%)
  • Frost or ice22 (4.3%)
  • Snow6 (1.2%)
  • Flood over 3cm deep3 (0.6%)
  • Not recorded2 (0.4%)

Type of road

  • Single carriageway483 (95%)
  • Roundabout20 (3.9%)
  • Dual carriageway1 (0.2%)
  • One way street or slip road1 (0.2%)
  • Not recorded3 (0.6%)

Source: Department for Transport, STATS19 road safety data

People hurt and vehicles involved in B4505 crashes

Car occupants make up 72% of the people killed or injured on the B4505, followed by motorcyclists (13%).

Casualties by road user

  • Car occupant525 (72%)
  • Motorcyclist94 (13%)
  • Cyclist35 (4.8%)
  • Pedestrian32 (4.4%)
  • Van occupant18 (2.5%)
  • Bus or coach occupant8 (1.1%)
  • Goods vehicle occupant (over 3.5 tonnes)8 (1.1%)
  • Other9 (1.2%)

Vehicles involved

  • Car756 (76%)
  • Motorcycle94 (9.4%)
  • Van or goods vehicle up to 3.5 tonnes49 (4.9%)
  • Goods vehicle over 3.5 tonnes38 (3.8%)
  • Pedal cycle37 (3.7%)
  • Bus or coach6 (0.6%)
  • Other15 (1.5%)
  • Not recorded1 (0.1%)

Casualties by age

  • 0 to 57 (1%)
  • 6 to 1012 (1.6%)
  • 11 to 1533 (4.5%)
  • 16 to 20194 (27%)
  • 21 to 25109 (15%)
  • 26 to 35127 (17%)
  • 36 to 45101 (14%)
  • 46 to 5564 (8.8%)
  • 56 to 6538 (5.2%)
  • 66 to 7521 (2.9%)
  • Over 7518 (2.5%)
  • Not recorded5 (0.7%)

Drivers, passengers and pedestrians

  • Driver or rider494 (68%)
  • Passenger203 (28%)
  • Pedestrian32 (4.4%)

Source: Department for Transport, STATS19 road safety data

Map of recent crashes on the B4505

Map of the 25 most recent crashes on the B4505

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

  • 25 crashes
  • Serious
  • Slight

B4505 crashes by council area

Collisions on the B4505 were recorded in 2 council areas. Dacorum has the most, with 343, followed by Buckinghamshire (162).

Collisions on the B4505 in each area, 1979 to 2025
RankAreaCollisionsCasualtiesFatalSerious
1stDacorum343517685
2ndBuckinghamshire162209434

B4505 crashes by town

Collisions on the B4505 were recorded in 3 towns and built-up areas, led by Bovingdon (134) and Hemel Hempstead (72).

Recent crashes on the B4505

These are the 25 most recent collisions on the B4505, from 13 February 2018 to 27 September 2025.

Severity