Motorway

A48(M) traffic and collisions

The A48(M) is a motorway of 2.4 miles, from Newport to Cardiff. This page covers its traffic at 2 DfT count points since 2016 and the collisions police recorded on it.

Last updated
Records analysed
2 count points in 2025
Methodology
View methodology
  • Traffic in 2025 44m vehicle miles
  • Average daily traffic 49,616 vehicles a day, both directions
  • Busiest section 49,616 J29A to J29
  • HGV share 6.0% of vehicle miles
  • Traffic since 2019 +5.1% same count points
  • Collisions, 2021 to 2025 3 fewer than 3 fatal or serious

How busy is the A48(M)?

On an average day in 2025, 49,616 vehicles passed each point on the A48(M), counting both directions.

Route

Newport to Cardiff · 2.4 miles

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

A48(M) traffic and collisions by section

1 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 A48(M) in route order, 2025 traffic
#
1J29A to J29Newport, Cardiff2.449,6166.0%+5.1%0

Vehicles a day is the average daily flow in 2025. “Since 2019” compares the same count points. Collisions are those with the A48(M) 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.

A48(M) traffic by vehicle type

Cars and taxis make up 79.9% of the vehicle miles on the A48(M). HGVs account for 6.0%.

Vehicle mix, 2025

Source:DfT,UK Motoring analysis 2016 to 2025 Updated

HGV share of traffic

HGVs as a share of vehicle miles on the A48(M), by year
Year HGV share
2016 6.5%
2017 6.8%
2018 6.9%
2019 6.8%
2020 8.8%
2021 8.5%
2022 7.7%
2023 7.3%
2024 6.0%
2025 6.0%

Source:DfT,UK Motoring analysis 2016 to 2025 Updated

A48(M) traffic trend

Traffic on the A48(M) came to 43.5 million vehicle miles in 2025. At the count points present in both years, it is up 5.1% on 2019, before the pandemic.

Vehicle miles a year

Vehicle miles on the A48(M) each year, the whole road as it was that year
Year Vehicle miles
2016 41m
2017 41m
2018 41m
2019 41m
2020 26m
2021 30m
2022 34m
2023 34m
2024 43m
2025 44m

Source:DfT,UK Motoring analysis 2016 to 2025 Updated

Average daily flow

Average daily flow along the A48(M), weighted by link length, by year
Year Vehicles a day
2016 46,232
2017 46,726
2018 46,626
2019 47,203
2020 29,776
2021 34,027
2022 38,251
2023 39,208
2024 48,719
2025 49,616

Source:DfT,UK Motoring analysis 2016 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 2 count points were counted; DfT estimated the rest from earlier counts and local trends.

A48(M) collisions

Police recorded 3 collisions with the A48(M) as the first road from 2021 to 2025, fewer than 3 of them fatal or serious.

Reported collisions by year

Police-reported collisions on the A48(M) by year
Year Collisions Fatal or serious
2021 0 0
2022 fewer than 3 0
2023 fewer than 3 0
2024 0 0
2025 0 0

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

Fatal or serious uses DfT’s adjusted serious figures. 0.0% of the collisions could be placed on a section. How we count collisions

Council areas on the A48(M)

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

  • Newport
  • Cardiff

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
2016 to 2025 2 count points in 2025 15 September 2026
Reported collisions Road safety open data (STATS19) Department for Transport
Derived statistics UK Motoring
2021 to 2025 3 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.