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CrashStats

B4312 accidents: crash map and statistics

Police recorded 301 collisions on the B4312 from 1979 to 2025, with 446 casualties. Of those crashes, 11 were fatal and 76 serious, and 12 people were killed.

In 2025 there were 3 collisions on the B4312, down 25% from 4 in 2024, with 6 casualties.

Collisions since 1979
301
2,687th highest of 4,923 roads
Casualties
446
1.48 per collision
Fatal collisions
11
12 people killed
Serious collisions
76
96 seriously injured
Collisions in 2025
3
Down 25% on 2024
Casualties in 2025
6
Level with 2024

Crash severity on the B4312

On the B4312, 3.7% of collisions were fatal and 25% serious, against 1.6% and 18% across Great Britain.

Collisions by severity, 1979 to 2025

  • Fatal113.7%
  • Serious7625%
  • Slight21471%

Where the B4312 ranks among 4,923 roads

Most collisions
2,687th
Most casualties
2,569th
Most fatal collisions
1,595th
Most serious collisions
2,368th

B4312 accidents by year

Collisions on the B4312 peaked at 14 in 1994 and were down to 3 in 2025.

Collisions and casualties on the B4312, 1979 to 2025

  • Collisions
  • Collisions in 2025
  • Casualties

Source: Department for Transport, STATS19 road safety data

View as a table
YearCollisionsCasualties
202536
202446
202333
202235
2021611
202033
201968
201833
2017812
201635
2015710
201444
201367
201255
201123
20101014
200933
200844
2007917
20061118
200556
200435
200359
2002612
2001710
20001219
199988
1998712
1997713
199646
19951013
19941423
1993711
1992811
199189
1990812
19891012
1988913
198745
1986915
1985613
1984910
19831118
198259
198157
1980814
197934

When crashes happen on the B4312

Wednesday has the most collisions on the B4312 (54), and noon to 3pm is the busiest time of day (67).

Collisions by day of the week

  • Monday53 (18%)
  • Tuesday42 (14%)
  • Wednesday54 (18%)
  • Thursday41 (14%)
  • Friday43 (14%)
  • Saturday44 (15%)
  • Sunday24 (8%)

Collisions by time of day

  • Midnight to 3am7 (2.3%)
  • 3am to 6am6 (2%)
  • 6am to 9am40 (13%)
  • 9am to noon44 (15%)
  • Noon to 3pm67 (22%)
  • 3pm to 6pm67 (22%)
  • 6pm to 9pm48 (16%)
  • 9pm to midnight22 (7.3%)

Collisions by month

  • January25 (8.3%)
  • February27 (9%)
  • March23 (7.6%)
  • April21 (7%)
  • May26 (8.6%)
  • June28 (9.3%)
  • July29 (9.6%)
  • August23 (7.6%)
  • September25 (8.3%)
  • October23 (7.6%)
  • November25 (8.3%)
  • December26 (8.6%)

Light conditions at the time

  • Daylight237 (79%)
  • Dark, no street lighting30 (10%)
  • Dark, street lights lit29 (9.6%)
  • Dark, lighting unknown2 (0.7%)
  • Dark, street lights unlit1 (0.3%)
  • Not recorded2 (0.7%)

Source: Department for Transport, STATS19 road safety data

Road and weather conditions in B4312 crashes

On the B4312, 58% of collisions happened where the speed limit was 30 mph and 63% on a dry road surface.

Speed limit at the scene

  • 20 mph6 (2%)
  • 30 mph176 (58%)
  • 40 mph3 (1%)
  • 50 mph9 (3%)
  • 60 mph107 (36%)

Weather at the time

  • Fine, no high winds216 (72%)
  • Raining, no high winds46 (15%)
  • Raining with high winds8 (2.7%)
  • Fine with high winds7 (2.3%)
  • Other17 (5.6%)
  • Not recorded7 (2.3%)

Road surface

  • Dry189 (63%)
  • Wet or damp101 (34%)
  • Frost or ice7 (2.3%)
  • Flood over 3cm deep1 (0.3%)
  • Snow1 (0.3%)
  • Not recorded2 (0.7%)

Type of road

  • Single carriageway290 (96%)
  • Roundabout5 (1.7%)
  • Dual carriageway3 (1%)
  • One way street or slip road2 (0.7%)
  • Not recorded1 (0.3%)

Source: Department for Transport, STATS19 road safety data

People hurt and vehicles involved in B4312 crashes

Car occupants make up 71% of the people killed or injured on the B4312, followed by pedestrians (11%).

Casualties by road user

  • Car occupant316 (71%)
  • Pedestrian50 (11%)
  • Motorcyclist38 (8.5%)
  • Cyclist16 (3.6%)
  • Van occupant14 (3.1%)
  • Taxi or private hire car occupant7 (1.6%)
  • Goods vehicle occupant (over 3.5 tonnes)2 (0.4%)
  • Other3 (0.7%)

Vehicles involved

  • Car407 (79%)
  • Motorcycle35 (6.8%)
  • Van or goods vehicle up to 3.5 tonnes29 (5.6%)
  • Pedal cycle17 (3.3%)
  • Goods vehicle over 3.5 tonnes12 (2.3%)
  • Agricultural vehicle5 (1%)
  • Other vehicle4 (0.8%)
  • Other8 (1.5%)

Casualties by age

  • 0 to 56 (1.3%)
  • 6 to 1018 (4%)
  • 11 to 1544 (9.9%)
  • 16 to 20109 (24%)
  • 21 to 2557 (13%)
  • 26 to 3544 (9.9%)
  • 36 to 4557 (13%)
  • 46 to 5542 (9.4%)
  • 56 to 6525 (5.6%)
  • 66 to 7528 (6.3%)
  • Over 7516 (3.6%)

Drivers, passengers and pedestrians

  • Driver or rider253 (57%)
  • Passenger143 (32%)
  • Pedestrian50 (11%)

Source: Department for Transport, STATS19 road safety data

Map of recent crashes on the B4312

Map of the 25 most recent crashes on the B4312

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

  • 25 crashes
  • Serious
  • Slight

B4312 crashes by council area

All 301 collisions on the B4312 were in Carmarthenshire.

Collisions on the B4312 in each area, 1979 to 2025
RankAreaCollisionsCasualtiesFatalSerious
1stCarmarthenshire3014461176

B4312 crashes by town

Of the 301 collisions on the B4312, 155 were in the built-up area of Carmarthen.

Recent crashes on the B4312

These are the 25 most recent collisions on the B4312, from 27 September 2019 to 14 November 2025.

Severity