Trunk A-road

A4232 traffic and collisions

The A4232 is a trunk A-road of 13.1 miles, in Cardiff. This page covers its traffic at 13 DfT count points since 2000 and the collisions police recorded on it.

Last updated
Records analysed
13 count points in 2025
Methodology
View methodology
  • Traffic in 2025 244m vehicle miles
  • Average daily traffic 51,023 vehicles a day, both directions
  • Busiest section 60,908 A4055 to B4267
  • HGV share 3.8% of vehicle miles
  • Traffic since 2019 −8.9% same count points
  • Collisions, 2021 to 2025 90 7.7 per 100m vehicle miles

How busy is the A4232?

On an average day in 2025, 51,023 vehicles passed each point on the A4232, counting both directions. The busiest section is A4055 to B4267 (Cardiff, The Vale of Glamorgan), with 60,908 a day; the quietest listed is Ocean Way - Rover Way roundabout to A4234, with 19,956.

Busiest sections, 2025

A4055 to B4267 carries 1.2 times the road’s average flow.

Sections of the A4232 with the highest average daily flow, 2025
Section Vehicles a day
A4055 to B4267 Cardiff, The Vale of Glamorgan · 1.9 mi · HGVs 3.4% 60,908
B4267 mid-junction to A48/A4050 Cardiff · 2.9 mi · HGVs 3.4% 60,908
A48 / A4050 to M4 Junction 33 Cardiff · 3.6 mi · HGVs 4.5% 60,565
A470 to A4055 Cardiff · 1.2 mi · HGVs 3.1% 47,046
A4234 to A470 Cardiff · 0.6 mi · HGVs 3.0% 44,924
Count point 92140 Cardiff · 0.9 mi · HGVs 5.2% 28,353
M4 Junction 30 to A48 Cardiff · 0.7 mi · HGVs 3.1% 27,521
A48 to road to Llanedeyrn Cardiff · 0.6 mi · HGVs 3.1% 26,421
Ocean Way - Rover Way roundabout to A4234 Cardiff · 0.7 mi · HGVs 5.5% 19,956

Source:DfT,UK Motoring analysis 2000 to 2025 Updated

Route

In Cardiff · 13.1 miles

Cardiff
Schematic route: each line joins the junctions at the ends of a DfT count point link.

A4232 traffic and collisions by section

9 sections between junctions, in route order. Each is the average of its DfT count points, weighted by length.

Sections Tap a column heading to sort
Sections of the A4232 in route order, 2025 traffic
#
1M4 Junction 30 to A48Cardiff0.727,5213.1%+0.1%6
2A48 to road to LlanedeyrnCardiff0.626,4213.1%+0.1%5
3Count point 92140Cardiff0.928,3535.2%1736.9
4Ocean Way - Rover Way roundabout to A4234Cardiff0.719,9565.5%−4.9%3
5A4234 to A470Cardiff0.644,9243.0%−4.3%5
6A470 to A4055Cardiff1.247,0463.1%−9.9%8
7A4055 to B4267Cardiff, The Vale of Glamorgan1.960,9083.4%−4.7%6
8B4267 mid-junction to A48/A4050Cardiff2.960,9083.4%−4.7%165.3
9A48 / A4050 to M4 Junction 33Cardiff3.660,5654.5%−15.7%246.1

Vehicles a day is the average daily flow in 2025. “Since 2019” compares the same count points. Collisions are those with the A4232 as the first road, placed on the nearest section by their recorded position; rates (per 100 million vehicle miles) are shown for sections of half a mile or more with 10 or more.

A4232 traffic by vehicle type

Cars and taxis make up 79.6% of the vehicle miles on the A4232. HGVs account for 3.8%, rising to 5.5% on Ocean Way - Rover Way roundabout to A4234.

Vehicle mix, 2025

Source:DfT,UK Motoring analysis 2000 to 2025 Updated

HGV share of traffic

HGVs as a share of vehicle miles on the A4232, by year
Year HGV share
2000 5.4%
2001 4.9%
2002 4.9%
2003 5.3%
2004 4.7%
2005 5.4%
2006 4.5%
2007 5.0%
2008 4.9%
2009 4.0%
2010 4.0%
2011 4.4%
2012 4.0%
2013 4.2%
2014 4.0%
2015 3.9%
2016 3.8%
2017 4.0%
2018 3.9%
2019 3.9%
2020 5.0%
2021 4.4%
2022 4.2%
2023 3.9%
2024 3.9%
2025 3.8%

Source:DfT,UK Motoring analysis 2000 to 2025 Updated

A4232 traffic trend

Traffic on the A4232 came to 244 million vehicle miles in 2025. At the count points present in both years, it is down 8.9% on 2019, before the pandemic, and up 3.2% on 2015.

Vehicle miles a year

Like for like, traffic is up 57.2% on 2000.

Vehicle miles on the A4232 each year, the whole road as it was that year
Year Vehicle miles
2000 171m
2001 184m
2002 182m
2003 195m
2004 208m
2005 186m
2006 208m
2007 202m
2008 194m
2009 198m
2010 187m
2011 202m
2012 206m
2013 205m
2014 213m
2015 223m
2016 238m
2017 232m
2018 251m
2019 266m
2020 189m
2021 212m
2022 234m
2023 245m
2024 234m
2025 244m

Source:DfT,UK Motoring analysis 2000 to 2025 Updated

Average daily flow

Average daily flow along the A4232, weighted by link length, by year
Year Vehicles a day
2000 39,769
2001 42,598
2002 42,217
2003 45,224
2004 48,254
2005 43,242
2006 48,225
2007 46,794
2008 44,980
2009 45,949
2010 43,425
2011 46,785
2012 47,730
2013 47,622
2014 49,356
2015 51,792
2016 53,469
2017 51,985
2018 52,391
2019 55,707
2020 39,572
2021 44,226
2022 48,910
2023 51,282
2024 48,865
2025 51,023

Source:DfT,UK Motoring analysis 2000 to 2025 Updated

The chart counts the whole road as it was each year, so new or renumbered stretches move it. The percentage changes compare only count points present in both years. In 2025, 6 of the 13 count points were counted; DfT estimated the rest from earlier counts and local trends.

A4232 collisions

Police recorded 90 collisions with the A4232 as the first road from 2021 to 2025, fewer than 3 of them fatal or serious. That is 7.7 per 100 million vehicle miles, lower than the 31.5 for all A-roads in Great Britain. On average there were 1.4 a year for each mile of road.

Reported collisions by year

Up 108.3% from 2021 to 2025.

Police-reported collisions on the A4232 by year
Year Collisions
2021 12
2022 20
2023 15
2024 18
2025 25

Source:DfT STATS19,UK Motoring analysis 2021 to 2025 Updated

Sections with the highest collision rates

Per 100 million vehicle miles, 2021 to 2025. Sections of half a mile or more with 10 or more collisions.

Collisions per 100 million vehicle miles by section of the A4232, 2021 to 2025
Section Per 100m vehicle miles
Count point 92140 Cardiff · 17 collisions 36.9
A48 / A4050 to M4 Junction 33 Cardiff · 24 collisions 6.1
B4267 mid-junction to A48/A4050 Cardiff · 16 collisions 5.3

Source:DfT STATS19,UK Motoring analysis 2021 to 2025 Updated

A further 18 collisions were recorded at junctions where the A4232 was the second road; they are not in the figures above. Fatal or serious uses DfT’s adjusted serious figures. 100.0% of the collisions could be placed on a section. How we count collisions

Council areas on the A4232

In route order. Each is the highway authority DfT files the count points under.

  • Cardiff
  • The Vale of Glamorgan

Data sources and methodology

Datasets used on this page
Figures Source Period Records Updated
Traffic counts and vehicle mix Road traffic statistics (AADF by count point) Department for Transport
Derived statistics UK Motoring
2000 to 2025 13 count points in 2025 15 September 2026
Reported collisions Road safety open data (STATS19) Department for Transport
Derived statistics UK Motoring
2021 to 2025 90 reported collisions 15 September 2026
  • Annual average daily flow (AADF) is the average number of vehicles passing a point on a typical day of the year, both directions combined.
  • Vehicle miles are AADF multiplied by link length and 365, summed over every count point link on the road.
  • Sections join count point links between junctions, using the link lines in DfT’s major road database.
  • STATS19 covers personal injury collisions reported to the police. Damage-only collisions are not included, and not every injury collision is reported.
  • Serious and slight figures are DfT’s adjusted estimates, which allow for police forces moving to injury-based reporting.
  • Counts of one or two collisions below Great Britain level are shown as “fewer than 3”.

Contains public sector information licensed under the Open Government Licence v3.0.