Trunk A-road
A423 traffic and collisions
The A423 is a trunk A-road of 24.9 miles, from Oxfordshire to Warwickshire. This page covers its traffic at 9 DfT count points since 2000 and the collisions police recorded on it.
- Traffic in 2025 99m vehicle miles
- Average daily traffic 10,845 vehicles a day, both directions
- Busiest section 54,275 A34(T) to Abingdon Rd
- HGV share 5.5% of vehicle miles
- Traffic since 2019 +1.4% same count points
- Collisions, 2021 to 2025 86 18.7 per 100m vehicle miles
How busy is the A423?
On an average day in 2025, 10,845 vehicles passed each point on the A423, counting both directions. The busiest section is A34(T) to Abingdon Rd (Oxfordshire), with 54,275 a day; the quietest listed is A422 to A425, with 6,374.
Busiest sections, 2025
A34(T) to Abingdon Rd carries 5.0 times the road’s average flow.
| Section | Vehicles a day |
|---|---|
| A34(T) to Abingdon Rd Oxfordshire · 0.7 mi · HGVs 4.1% | 54,275 |
| A4142 / A4074 Heyford hill to A4144 Oxfordshire · 0.9 mi · HGVs 3.3% | 53,050 |
| A425W to A425E Warwickshire · 0.6 mi · HGVs 5.5% | 14,497 |
| A445 to A45 Warwickshire · 1.2 mi · HGVs 6.9% | 11,445 |
| A45 to A445 Warwickshire · 0.5 mi · HGVs 6.9% | 11,445 |
| A425 to A426 Warwickshire · 0.7 mi · HGVs 5.2% | 9,330 |
| A426 to Roundabout A445/A423 Warwickshire · 7.5 mi · HGVs 6.5% | 9,071 |
| A422 to A425 Oxfordshire, Warwickshire · 12.8 mi · HGVs 6.2% | 6,374 |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
Route
Oxfordshire to Warwickshire · 24.9 miles in 2 stretches
A423 traffic and collisions by section
8 sections between junctions, in route order (2 separate stretches). Each is the average of its DfT count points, weighted by length.
Sections Tap a column heading to sort
| # | |||
|---|---|---|---|
| 1 | A4142 / A4074 Heyford hill to A4144Oxfordshire · stretch 1 | 53,050 | 18 |
| 2 | A34(T) to Abingdon RdOxfordshire · stretch 1 | 54,275 | 15 |
| 3 | A422 to A425Oxfordshire, Warwickshire · stretch 2 | 6,374 | 33 |
| 4 | A425W to A425EWarwickshire · stretch 2 | 14,497 | fewer than 3 |
| 5 | A425 to A426Warwickshire · stretch 2 | 9,330 | fewer than 3 |
| 6 | A426 to Roundabout A445/A423Warwickshire · stretch 2 | 9,071 | 16 |
| 7 | A445 to A45Warwickshire · stretch 2 | 11,445 | fewer than 3 |
| 8 | A45 to A445Warwickshire · stretch 2 | 11,445 | fewer than 3 |
Vehicles a day is the average daily flow in 2025. “Since 2019” compares the same count points. Collisions are those with the A423 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.
A423 traffic by vehicle type
Cars and taxis make up 78.6% of the vehicle miles on the A423. HGVs account for 5.5%, rising to 6.9% on A445 to A45.
Vehicle mix, 2025
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
HGV share of traffic
| Year | HGV share |
|---|---|
| 2000 | 6.7% |
| 2001 | 7.1% |
| 2002 | 7.8% |
| 2003 | 7.4% |
| 2004 | 7.9% |
| 2005 | 7.2% |
| 2006 | 6.6% |
| 2007 | 6.7% |
| 2008 | 6.3% |
| 2009 | 5.8% |
| 2010 | 5.8% |
| 2011 | 5.8% |
| 2012 | 6.0% |
| 2013 | 5.9% |
| 2014 | 6.1% |
| 2015 | 6.3% |
| 2016 | 6.0% |
| 2017 | 5.6% |
| 2018 | 5.6% |
| 2019 | 5.5% |
| 2020 | 6.7% |
| 2021 | 6.5% |
| 2022 | 5.8% |
| 2023 | 5.7% |
| 2024 | 5.7% |
| 2025 | 5.5% |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
A423 traffic trend
Traffic on the A423 came to 98.6 million vehicle miles in 2025. At the count points present in both years, it is up 1.4% on 2019, before the pandemic, and up 8.5% on 2015.
Vehicle miles a year
Like for like, traffic is up 2.5% on 2000.
| Year | Vehicle miles |
|---|---|
| 2000 | 81m |
| 2001 | 79m |
| 2002 | 79m |
| 2003 | 81m |
| 2004 | 84m |
| 2005 | 82m |
| 2006 | 82m |
| 2007 | 81m |
| 2008 | 80m |
| 2009 | 79m |
| 2010 | 77m |
| 2011 | 78m |
| 2012 | 78m |
| 2013 | 83m |
| 2014 | 84m |
| 2015 | 85m |
| 2016 | 87m |
| 2017 | 93m |
| 2018 | 96m |
| 2019 | 98m |
| 2020 | 74m |
| 2021 | 84m |
| 2022 | 91m |
| 2023 | 91m |
| 2024 | 95m |
| 2025 | 99m |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
Average daily flow
| Year | Vehicles a day |
|---|---|
| 2000 | 9,330 |
| 2001 | 9,091 |
| 2002 | 9,101 |
| 2003 | 9,331 |
| 2004 | 9,581 |
| 2005 | 9,439 |
| 2006 | 9,436 |
| 2007 | 9,281 |
| 2008 | 9,214 |
| 2009 | 9,093 |
| 2010 | 8,852 |
| 2011 | 8,912 |
| 2012 | 8,885 |
| 2013 | 9,491 |
| 2014 | 9,605 |
| 2015 | 9,708 |
| 2016 | 9,983 |
| 2017 | 10,361 |
| 2018 | 10,562 |
| 2019 | 10,788 |
| 2020 | 8,094 |
| 2021 | 9,192 |
| 2022 | 9,991 |
| 2023 | 10,007 |
| 2024 | 10,458 |
| 2025 | 10,845 |
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 (69.9% of today’s road for 2019). In 2025, 1 of the 9 count points were counted; DfT estimated the rest from earlier counts and local trends.
A423 collisions
Police recorded 86 collisions with the A423 as the first road from 2021 to 2025, 34 of them fatal or serious, including 5 fatal. That is 18.7 per 100 million vehicle miles, lower than the 31.5 for all A-roads in Great Britain. On average there were 0.7 a year for each mile of road.
Reported collisions by year
Up 31.3% from 2021 to 2025.
| Year | Slight | Fatal or serious |
|---|---|---|
| 2021 | 13 | 3 |
| 2022 | 10 | 6 |
| 2023 | 9 | 9 |
| 2024 | 10 | 5 |
| 2025 | 11 | 10 |
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.
| Section | Per 100m vehicle miles |
|---|---|
| A422 to A425 Oxfordshire, Warwickshire · 33 collisions | 25.8 |
| A34(T) to Abingdon Rd Oxfordshire · 15 collisions | 22.5 |
| A4142 / A4074 Heyford hill to A4144 Oxfordshire · 18 collisions | 21.4 |
| A426 to Roundabout A445/A423 Warwickshire · 16 collisions | 13.4 |
Source:DfT STATS19,UK Motoring analysis 2021 to 2025 Updated
A further 6 collisions were recorded at junctions where the A423 was the second road; they are not in the figures above. Fatal or serious uses DfT’s adjusted serious figures. How we count collisions
Council areas on the A423
In route order. Each is the highway authority DfT files the count points under.
- Oxfordshire
- Warwickshire
Data sources and methodology
| 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 | 9 count points in 2025 | 15 September 2026 |
| Reported collisions | Road safety open data (STATS19) Department for Transport Derived statistics UK Motoring | 2021 to 2025 | 86 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.