Skip to main content
CrashStats

SL9 road accidents: crash map and statistics

Police recorded 3,573 road traffic collisions in the SL9 postcode district, Buckinghamshire, from 1979 to 2025, and 5,179 people were killed or injured in them. Of those collisions, 81 were fatal and 622 were serious.

In 2025 police recorded 32 collisions, up 19% on 2024 (27).

Collisions since 1979
3,573
1,051st highest of 2,813 postcode districts
Casualties
5,179
1.45 per collision
Fatal collisions
81
95 people killed
Serious collisions
622
781 seriously injured
Collisions in 2025
32
Up 19% on 2024
Casualties in 2025
33
Down 18% on 2024

Road collision statistics for SL9

Collisions by severity, 1979 to 2025

  • Fatal812.3%
  • Serious62217%
  • Slight2,87080%

What the data shows

  • SL9 had 382 collisions from 2016 to 2025, 46% fewer than the 714 from 2006 to 2015.
  • 20% of collisions in SL9 were fatal or serious, against 20% across Great Britain.
  • 404 children under 16 were killed or injured in SL9, 7.9% of the casualties whose age was recorded.
  • The road surface was wet, icy, snowy or flooded in 35% of collisions in SL9.

Where SL9 ranks among 2,813 postcode districts

Most collisions
1,051st
Most casualties
937th
Most fatal collisions
495th
Most serious collisions
1,143rd

Collisions by day of the week

  • Monday512 (14%)
  • Tuesday452 (13%)
  • Wednesday536 (15%)
  • Thursday554 (16%)
  • Friday623 (17%)
  • Saturday459 (13%)
  • Sunday437 (12%)

Light conditions

  • Daylight2,395 (67%)
  • Dark, street lights lit702 (20%)
  • Dark, no street lighting356 (10%)
  • Dark, lighting unknown89 (2.5%)
  • Dark, street lights unlit28 (0.8%)
  • Not recorded3 (0.1%)

Type of road

  • Single carriageway1,835 (51%)
  • Dual carriageway1,547 (43%)
  • Roundabout90 (2.5%)
  • One way street or slip road89 (2.5%)
  • Not recorded12 (0.3%)

Speed limit at the scene

  • 20 mph1 (under 0.1%)
  • 30 mph1,106 (31%)
  • 40 mph149 (4.2%)
  • 50 mph339 (9.5%)
  • 60 mph401 (11%)
  • 70 mph1,575 (44%)
  • Not recorded2 (0.1%)

Weather at the time

  • Fine, no high winds2,832 (79%)
  • Raining, no high winds462 (13%)
  • Raining with high winds44 (1.2%)
  • Fog or mist36 (1%)
  • Fine with high winds35 (1%)
  • Snowing, no high winds16 (0.4%)
  • Snowing with high winds2 (0.1%)
  • Other115 (3.2%)
  • Not recorded31 (0.9%)

Who was hurt

  • Car occupant3,834 (74%)
  • Motorcyclist427 (8.2%)
  • Pedestrian351 (6.8%)
  • Cyclist211 (4.1%)
  • Van occupant183 (3.5%)
  • Goods vehicle occupant (over 3.5 tonnes)87 (1.7%)
  • Taxi or private hire car occupant26 (0.5%)
  • Minibus occupant25 (0.5%)
  • Bus or coach occupant18 (0.3%)
  • Other vehicle occupant12 (0.2%)
  • Other4 (0.1%)
  • Not recorded1 (under 0.1%)

Source: Department for Transport, STATS19 road safety data

SL9 road accidents by year

Collisions and casualties in SL9, 1979 to 2025

Collisions in SL9 peaked at 130 in 1997; 2025 had 32.

  • Collisions
  • Collisions in 2025: 32
  • Casualties

Source: Department for Transport, STATS19 road safety data

View as a table
YearCollisionsCasualties
20253233
20242740
20232426
20224056
20214150
20203239
20193640
20185377
20174052
20165789
20154678
20145676
20135574
201274107
20115687
201073121
200984124
200878125
2007100189
200692130
200588128
200486131
200397129
200287134
2001125180
200096155
1999125184
1998105169
1997130168
199682146
199596133
199490127
199399148
199284100
1991102141
1990107167
1989112170
198898136
198782127
198691129
198576116
198487112
19837190
198285116
19816890
19804855
19796085

Map of recent crashes in SL9

Map of the 24 most recent crashes in SL9

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 SL9

The 24 most recent collisions in SL9 happened between 23 March and 23 December 2025.

Severity

Crashes by road in SL9

The M25 has the most collisions in SL9, 966 of 3,573 (27%), followed by the A413 (485).

Collisions in SL9 on each road, 1979 to 2025
RankRoadCollisionsCasualtiesFatalSerious
1stM259661,52614114
2ndA41348572327119
3rdM404276901568
4thA40405572884
5thB416339439362

Council areas covering SL9

Collisions in SL9 were recorded in 2 council areas. Buckinghamshire has 3,508 of 3,573 (98%).

Collisions in SL9 by council area, 1979 to 2025
RankCouncil areaCollisionsCasualtiesFatalSerious
1stBuckinghamshire3,5085,08181618
2ndThree Rivers639504

Towns in SL9

Collisions in SL9 were recorded in 2 towns, led by Chalfont St Peter (749) and Gerrards Cross (717).