A-road

A4059 traffic and collisions

The A4059 is an A-road of 21.8 miles, from Rhondda Cynon Taf to Powys. 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 108m vehicle miles
  • Average daily traffic 13,553 vehicles a day, both directions
  • Busiest section 23,841 A4233 to A465(T)
  • HGV share 2.9% of vehicle miles
  • Traffic since 2019 −12.0% same count points
  • Collisions, 2021 to 2025 87 19.8 per 100m vehicle miles

How busy is the A4059?

On an average day in 2025, 13,553 vehicles passed each point on the A4059, counting both directions. The busiest section is A4233 to A465(T) (Rhondda Cynon Taf), with 23,841 a day; the quietest listed is C road (Penderyn) to A470, with 1,314.

Busiest sections, 2025

A4233 to A465(T) carries 1.8 times the road’s average flow.

Sections of the A4059 with the highest average daily flow, 2025
Section Vehicles a day
A4233 to A465(T) Rhondda Cynon Taf · 4.0 mi · HGVs 1.8% 23,841
A470 to A4275 Rhondda Cynon Taf · 8.0 mi · HGVs 2.5% 22,550
A465 to C-road west of Chapel Rd, Penderyn Rhondda Cynon Taf · 2.4 mi · HGVs 15.1% 4,153
C road (Penderyn) to A470 Rhondda Cynon Taf, Powys · 7.4 mi · HGVs 7.6% 1,314

Source:DfT,UK Motoring analysis 2000 to 2025 Updated

Route

Rhondda Cynon Taf to Powys · 21.8 miles

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

A4059 traffic and collisions by section

4 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 A4059 in route order, 2025 traffic
#
1A470 to A4275Rhondda Cynon Taf8.022,5502.5%5177.5
2A4233 to A465(T)Rhondda Cynon Taf4.023,8411.8%1748.8
3A465 to C-road west of Chapel Rd, PenderynRhondda Cynon Taf2.44,15315.1%3
4C road (Penderyn) to A470Rhondda Cynon Taf, Powys7.41,3147.6%−12.0%1693.8

Vehicles a day is the average daily flow in 2025. “Since 2019” compares the same count points. Collisions are those with the A4059 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.

A4059 traffic by vehicle type

Cars and taxis make up 78.0% of the vehicle miles on the A4059. HGVs account for 2.9%, rising to 15.1% on A465 to C-road west of Chapel Rd, Penderyn.

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 A4059, by year
Year HGV share
2000 4.9%
2001 4.1%
2002 4.0%
2003 3.7%
2004 4.0%
2005 3.7%
2006 3.6%
2007 3.6%
2008 3.5%
2009 3.4%
2010 3.3%
2011 3.3%
2012 3.3%
2013 3.4%
2014 3.5%
2015 3.5%
2016 3.4%
2017 3.2%
2018 3.1%
2019 3.1%
2020 3.7%
2021 3.6%
2022 3.3%
2023 2.9%
2024 2.8%
2025 2.9%

Source:DfT,UK Motoring analysis 2000 to 2025 Updated

A4059 traffic trend

Traffic on the A4059 came to 108 million vehicle miles in 2025. At the count points present in both years, it is down 12.0% on 2019, before the pandemic, and down 8.4% on 2015.

Vehicle miles a year

Like for like, traffic is up 39.8% on 2000.

Vehicle miles on the A4059 each year, the whole road as it was that year
Year Vehicle miles
2000 72m
2001 73m
2002 76m
2003 77m
2004 77m
2005 79m
2006 83m
2007 86m
2008 85m
2009 85m
2010 83m
2011 83m
2012 84m
2013 85m
2014 84m
2015 87m
2016 82m
2017 81m
2018 81m
2019 83m
2020 62m
2021 68m
2022 76m
2023 90m
2024 98m
2025 108m

Source:DfT,UK Motoring analysis 2000 to 2025 Updated

Average daily flow

Average daily flow along the A4059, weighted by link length, by year
Year Vehicles a day
2000 9,528
2001 9,768
2002 10,098
2003 10,257
2004 10,261
2005 10,476
2006 11,014
2007 11,493
2008 11,334
2009 11,272
2010 11,026
2011 11,069
2012 11,220
2013 11,257
2014 11,106
2015 11,566
2016 10,907
2017 10,789
2018 10,758
2019 10,863
2020 8,150
2021 8,982
2022 9,965
2023 11,827
2024 12,942
2025 13,553

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 (33.9% of today’s road for 2019). In 2025, 0 of the 5 count points were counted; DfT estimated the rest from earlier counts and local trends.

A4059 collisions

Police recorded 87 collisions with the A4059 as the first road from 2021 to 2025, fewer than 3 of them fatal or serious, including 5 fatal. That is 19.8 per 100 million vehicle miles, lower than the 31.5 for all A-roads in Great Britain. On average there were 0.8 a year for each mile of road.

Reported collisions by year

About the same in 2025 as in 2021.

Police-reported collisions on the A4059 by year
Year Collisions
2021 17
2022 16
2023 27
2024 10
2025 17

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 A4059, 2021 to 2025
Section Per 100m vehicle miles
C road (Penderyn) to A470 Rhondda Cynon Taf, Powys · 16 collisions 93.8
A470 to A4275 Rhondda Cynon Taf · 51 collisions 77.5
A4233 to A465(T) Rhondda Cynon Taf · 17 collisions 48.8

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

A further 20 collisions were recorded at junctions where the A4059 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 A4059

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

  • Rhondda Cynon Taf
  • Powys

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 87 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.