A-road
A431 traffic and collisions
The A431 is an A-road of 9.2 miles, from Bath and North East Somerset to City of Bristol. This page covers its traffic at 7 DfT count points since 2000 and the collisions police recorded on it.
- Traffic in 2025 39m vehicle miles
- Average daily traffic 11,739 vehicles a day, both directions
- Busiest section 20,520 A4174 to A420
- HGV share 0.8% of vehicle miles
- Traffic since 2019 −5.5% same count points
- Collisions, 2021 to 2025 73 38.4 per 100m vehicle miles
How busy is the A431?
On an average day in 2025, 11,739 vehicles passed each point on the A431, counting both directions. The busiest section is A4174 to A420 (South Gloucestershire, City of Bristol), with 20,520 a day; the quietest listed is Penn Hill Rd, Bath to A4175, with 7,091.
Busiest sections, 2025
A4174 to A420 carries 1.7 times the road’s average flow.
| Section | Vehicles a day |
|---|---|
| A4174 to A420 South Gloucestershire, City of Bristol · 2.5 mi · HGVs 0.7% | 20,520 |
| A4175 to A4174 South Gloucestershire · 1.1 mi · HGVs 0.6% | 13,259 |
| A4 to Penn Hill Rd Bath and North East Somerset · 0.8 mi · HGVs 1.0% | 7,099 |
| Penn Hill Rd, Bath to A4175 Bath and North East Somerset, South Gloucestershire · 4.4 mi · HGVs 0.9% | 7,091 |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
Route
Bath and North East Somerset to City of Bristol · 9.2 miles
A431 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
| # | |||
|---|---|---|---|
| 1 | A4 to Penn Hill RdBath and North East Somerset | 7,099 | 4 |
| 2 | Penn Hill Rd, Bath to A4175Bath and North East Somerset, South Gloucestershire | 7,091 | 10 |
| 3 | At A4175South Gloucestershire | 13,088 | fewer than 3 |
| 4 | A4175 to A4174South Gloucestershire | 13,259 | 13 |
| 5 | A4174 to A420South Gloucestershire, City of Bristol | 20,520 | 44 |
Vehicles a day is the average daily flow in 2025. “Since 2019” compares the same count points. Collisions are those with the A431 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.
A431 traffic by vehicle type
Cars and taxis make up 82.3% of the vehicle miles on the A431. HGVs account for 0.8%.
Vehicle mix, 2025
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
HGV share of traffic
| Year | HGV share |
|---|---|
| 2000 | 1.4% |
| 2001 | 1.4% |
| 2002 | 1.4% |
| 2003 | 1.4% |
| 2004 | 1.3% |
| 2005 | 1.3% |
| 2006 | 1.2% |
| 2007 | 1.2% |
| 2008 | 1.1% |
| 2009 | 1.0% |
| 2010 | 1.0% |
| 2011 | 0.9% |
| 2012 | 0.9% |
| 2013 | 0.9% |
| 2014 | 1.0% |
| 2015 | 0.9% |
| 2016 | 0.9% |
| 2017 | 0.9% |
| 2018 | 0.9% |
| 2019 | 0.9% |
| 2020 | 1.0% |
| 2021 | 1.0% |
| 2022 | 0.9% |
| 2023 | 0.8% |
| 2024 | 0.8% |
| 2025 | 0.8% |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
A431 traffic trend
Traffic on the A431 came to 39.4 million vehicle miles in 2025. At the count points present in both years, it is down 5.5% on 2019, before the pandemic, and down 5.7% on 2015.
Vehicle miles a year
Like for like, traffic is down 1.4% on 2000.
| Year | Vehicle miles |
|---|---|
| 2000 | 40m |
| 2001 | 40m |
| 2002 | 41m |
| 2003 | 41m |
| 2004 | 42m |
| 2005 | 42m |
| 2006 | 43m |
| 2007 | 42m |
| 2008 | 41m |
| 2009 | 41m |
| 2010 | 42m |
| 2011 | 43m |
| 2012 | 43m |
| 2013 | 42m |
| 2014 | 43m |
| 2015 | 42m |
| 2016 | 43m |
| 2017 | 43m |
| 2018 | 42m |
| 2019 | 42m |
| 2020 | 32m |
| 2021 | 35m |
| 2022 | 38m |
| 2023 | 39m |
| 2024 | 39m |
| 2025 | 39m |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
Average daily flow
| Year | Vehicles a day |
|---|---|
| 2000 | 11,909 |
| 2001 | 11,899 |
| 2002 | 12,284 |
| 2003 | 12,254 |
| 2004 | 12,352 |
| 2005 | 12,485 |
| 2006 | 12,720 |
| 2007 | 12,409 |
| 2008 | 12,321 |
| 2009 | 12,331 |
| 2010 | 12,408 |
| 2011 | 12,819 |
| 2012 | 12,664 |
| 2013 | 12,619 |
| 2014 | 12,856 |
| 2015 | 12,443 |
| 2016 | 12,770 |
| 2017 | 12,817 |
| 2018 | 12,518 |
| 2019 | 12,428 |
| 2020 | 9,540 |
| 2021 | 10,485 |
| 2022 | 11,253 |
| 2023 | 11,538 |
| 2024 | 11,664 |
| 2025 | 11,739 |
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 7 count points were counted; DfT estimated the rest from earlier counts and local trends.
A431 collisions
Police recorded 73 collisions with the A431 as the first road from 2021 to 2025, 21 of them fatal or serious. That is 38.4 per 100 million vehicle miles, higher than the 31.5 for all A-roads in Great Britain. On average there were 1.6 a year for each mile of road.
Reported collisions by year
Down 18.8% from 2021 to 2025.
| Year | Collisions |
|---|---|
| 2021 | 16 |
| 2022 | 14 |
| 2023 | 13 |
| 2024 | 17 |
| 2025 | 13 |
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 |
|---|---|
| A4175 to A4174 South Gloucestershire · 13 collisions | 50.5 |
| A4174 to A420 South Gloucestershire, City of Bristol · 44 collisions | 48.8 |
| Penn Hill Rd, Bath to A4175 Bath and North East Somerset, South Gloucestershire · 10 collisions | 18.3 |
Source:DfT STATS19,UK Motoring analysis 2021 to 2025 Updated
A further 7 collisions were recorded at junctions where the A431 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 A431
In route order. Each is the highway authority DfT files the count points under.
- Bath and North East Somerset
- South Gloucestershire
- City of Bristol
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 | 7 count points in 2025 | 15 September 2026 |
| Reported collisions | Road safety open data (STATS19) Department for Transport Derived statistics UK Motoring | 2021 to 2025 | 73 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.