A-road

A4233 traffic and collisions

The A4233 is an A-road of 14.2 miles, in Rhondda Cynon Taf. This page covers its traffic at 5 DfT count points since 2000 and the collisions police recorded on it.

Last updated
Records analysed
5 count points in 2025
Methodology
View methodology
  • Traffic in 2025 39m vehicle miles
  • Average daily traffic 7,446 vehicles a day, both directions
  • Busiest section 12,952 Rhiwgarn, Trebanog to A4058
  • HGV share 1.2% of vehicle miles
  • Traffic since 2019 −5.2% same count points
  • Collisions, 2021 to 2025 45 24.8 per 100m vehicle miles

How busy is the A4233?

On an average day in 2025, 7,446 vehicles passed each point on the A4233, counting both directions. The busiest section is Rhiwgarn, Trebanog to A4058 (Rhondda Cynon Taf), with 12,952 a day; the quietest listed is Institute St, Maerdy to Highland Place, Blaengwawr, Aberdare, with 3,384.

Busiest sections, 2025

Rhiwgarn, Trebanog to A4058 carries 1.7 times the road’s average flow.

Sections of the A4233 with the highest average daily flow, 2025
Section Vehicles a day
Rhiwgarn, Trebanog to A4058 Rhondda Cynon Taf · 1.1 mi · HGVs 1.2% 12,952
A4058 Cemetery Rd, Porth to Institute St, Maerdy Rhondda Cynon Taf · 6.7 mi · HGVs 1.1% 9,219
A4119 to Rhiwgarn, Trebanog Rhondda Cynon Taf · 1.1 mi · HGVs 1.7% 7,293
Highland Place, Blaengwawr to A4059 Rhondda Cynon Taf · 1.1 mi · HGVs 0.9% 6,804
Institute St, Maerdy to Highland Place, Blaengwawr, Aberdare Rhondda Cynon Taf · 4.2 mi · HGVs 1.6% 3,384

Source:DfT,UK Motoring analysis 2000 to 2025 Updated

Route

In Rhondda Cynon Taf · 14.2 miles

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

A4233 traffic and collisions by section

5 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 A4233 in route order, 2025 traffic
#
1A4119 to Rhiwgarn, TrebanogRhondda Cynon Taf1.17,2931.7%−6.7%9
2Rhiwgarn, Trebanog to A4058Rhondda Cynon Taf1.112,9521.2%−1.3%4
3A4058 Cemetery Rd, Porth to Institute St, MaerdyRhondda Cynon Taf6.79,2191.1%−5.8%2119.4
4Institute St, Maerdy to Highland Place, Blaengwawr, AberdareRhondda Cynon Taf4.23,3841.6%−5.5%5
5Highland Place, Blaengwawr to A4059Rhondda Cynon Taf1.16,8040.9%6

Vehicles a day is the average daily flow in 2025. “Since 2019” compares the same count points. Collisions are those with the A4233 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.

A4233 traffic by vehicle type

Cars and taxis make up 76.8% of the vehicle miles on the A4233. HGVs account for 1.2%.

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 A4233, by year
Year HGV share
2000 2.2%
2001 2.2%
2002 2.0%
2003 1.9%
2004 2.0%
2005 2.1%
2006 2.6%
2007 2.1%
2008 1.8%
2009 1.6%
2010 1.7%
2011 1.7%
2012 1.7%
2013 1.7%
2014 1.7%
2015 1.7%
2016 1.6%
2017 1.5%
2018 1.2%
2019 1.1%
2020 1.4%
2021 1.3%
2022 1.3%
2023 1.2%
2024 1.2%
2025 1.2%

Source:DfT,UK Motoring analysis 2000 to 2025 Updated

A4233 traffic trend

Traffic on the A4233 came to 38.6 million vehicle miles in 2025. At the count points present in both years, it is down 5.2% on 2019, before the pandemic, and down 12.0% on 2015.

Vehicle miles a year

Like for like, traffic is up 7.3% on 2000.

Vehicle miles on the A4233 each year, the whole road as it was that year
Year Vehicle miles
2000 35m
2001 36m
2002 37m
2003 35m
2004 38m
2005 38m
2006 37m
2007 38m
2008 38m
2009 39m
2010 40m
2011 40m
2012 40m
2013 40m
2014 41m
2015 42m
2016 43m
2017 43m
2018 39m
2019 40m
2020 30m
2021 33m
2022 36m
2023 37m
2024 37m
2025 39m

Source:DfT,UK Motoring analysis 2000 to 2025 Updated

Average daily flow

Average daily flow along the A4233, weighted by link length, by year
Year Vehicles a day
2000 7,087
2001 7,323
2002 7,386
2003 7,056
2004 7,566
2005 7,647
2006 7,454
2007 7,642
2008 7,493
2009 7,818
2010 7,982
2011 8,057
2012 7,977
2013 7,979
2014 8,227
2015 8,398
2016 8,589
2017 8,656
2018 7,829
2019 7,873
2020 5,992
2021 6,612
2022 7,134
2023 7,287
2024 7,384
2025 7,446

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, 0 of the 5 count points were counted; DfT estimated the rest from earlier counts and local trends.

A4233 collisions

Police recorded 45 collisions with the A4233 as the first road from 2021 to 2025, 15 of them fatal or serious. That is 24.8 per 100 million vehicle miles, lower than the 31.5 for all A-roads in Great Britain. On average there were 0.6 a year for each mile of road.

Reported collisions by year

Up 37.5% from 2021 to 2025.

Police-reported collisions on the A4233 by year
Year Collisions
2021 8
2022 10
2023 7
2024 9
2025 11

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 A4233, 2021 to 2025
Section Per 100m vehicle miles
A4058 Cemetery Rd, Porth to Institute St, Maerdy Rhondda Cynon Taf · 21 collisions 19.4

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

A further 11 collisions were recorded at junctions where the A4233 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 A4233

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

  • Rhondda Cynon Taf

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 5 count points in 2025 15 September 2026
Reported collisions Road safety open data (STATS19) Department for Transport
Derived statistics UK Motoring
2021 to 2025 45 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.