A-road
A340 traffic and collisions
The A340 is an A-road of 16.1 miles, from West Berkshire to Hampshire. This page covers its traffic at 9 DfT count points since 2000 and the collisions police recorded on it.
- Traffic in 2025 76m vehicle miles
- Average daily traffic 12,914 vehicles a day, both directions
- Busiest section 29,139 A339 to A3010
- HGV share 3.4% of vehicle miles
- Traffic since 2019 −8.7% same count points
- Collisions, 2021 to 2025 111 30.2 per 100m vehicle miles
How busy is the A340?
On an average day in 2025, 12,914 vehicles passed each point on the A340, counting both directions. The busiest section is A339 to A3010 (Hampshire), with 29,139 a day; the quietest listed is A4 to Church Rd, with 7,483.
Busiest sections, 2025
A339 to A3010 carries 2.3 times the road’s average flow.
| Section | Vehicles a day |
|---|---|
| A339 to A3010 Hampshire · 0.8 mi · HGVs 1.1% | 29,139 |
| A3010 to A30 Hampshire · 0.9 mi · HGVs 1.2% | 24,138 |
| Priestley Rd to A339 Hampshire · 0.5 mi · HGVs 3.0% | 15,458 |
| Knapp Lane, Tadley to Priestley Rd, Basingstoke Hampshire · 4.3 mi · HGVs 3.0% | 13,926 |
| B3051 to Knapp Lane, Tadley West Berkshire, Hampshire · 2.3 mi · HGVs 4.3% | 12,868 |
| A329 to A4 West Berkshire · 3.7 mi · HGVs 3.1% | 10,415 |
| Church rd to B3051 West Berkshire · 1.7 mi · HGVs 7.9% | 7,595 |
| A4 to Church Rd West Berkshire · 1.9 mi · HGVs 7.6% | 7,483 |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
Route
West Berkshire to Hampshire · 16.1 miles
A340 traffic and collisions by section
8 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 | A329 to A4West Berkshire | 10,415 | 19 |
| 2 | A4 to Church RdWest Berkshire | 7,483 | 4 |
| 3 | Church rd to B3051West Berkshire | 7,595 | fewer than 3 |
| 4 | B3051 to Knapp Lane, TadleyWest Berkshire, Hampshire | 12,868 | 14 |
| 5 | Knapp Lane, Tadley to Priestley Rd, BasingstokeHampshire | 13,926 | 26 |
| 6 | Priestley Rd to A339Hampshire | 15,458 | 15 |
| 7 | A339 to A3010Hampshire | 29,139 | 25 |
| 8 | A3010 to A30Hampshire | 24,138 | 6 |
Vehicles a day is the average daily flow in 2025. “Since 2019” compares the same count points. Collisions are those with the A340 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.
A340 traffic by vehicle type
Cars and taxis make up 80.6% of the vehicle miles on the A340. HGVs account for 3.4%, rising to 7.9% on Church rd to B3051.
Vehicle mix, 2025
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
HGV share of traffic
| Year | HGV share |
|---|---|
| 2000 | 3.9% |
| 2001 | 3.5% |
| 2002 | 3.3% |
| 2003 | 3.4% |
| 2004 | 4.1% |
| 2005 | 3.9% |
| 2006 | 4.3% |
| 2007 | 4.5% |
| 2008 | 3.9% |
| 2009 | 3.7% |
| 2010 | 3.6% |
| 2011 | 3.7% |
| 2012 | 3.5% |
| 2013 | 3.5% |
| 2014 | 3.6% |
| 2015 | 3.8% |
| 2016 | 3.8% |
| 2017 | 3.9% |
| 2018 | 4.0% |
| 2019 | 3.4% |
| 2020 | 4.0% |
| 2021 | 3.7% |
| 2022 | 3.7% |
| 2023 | 3.5% |
| 2024 | 3.5% |
| 2025 | 3.4% |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
A340 traffic trend
Traffic on the A340 came to 75.9 million vehicle miles in 2025. At the count points present in both years, it is down 8.7% on 2019, before the pandemic, and down 12.8% on 2015.
Vehicle miles a year
Like for like, traffic is down 5.3% on 2000.
| Year | Vehicle miles |
|---|---|
| 2000 | 79m |
| 2001 | 82m |
| 2002 | 82m |
| 2003 | 85m |
| 2004 | 83m |
| 2005 | 83m |
| 2006 | 77m |
| 2007 | 81m |
| 2008 | 84m |
| 2009 | 83m |
| 2010 | 81m |
| 2011 | 82m |
| 2012 | 80m |
| 2013 | 80m |
| 2014 | 83m |
| 2015 | 85m |
| 2016 | 87m |
| 2017 | 87m |
| 2018 | 88m |
| 2019 | 83m |
| 2020 | 63m |
| 2021 | 70m |
| 2022 | 73m |
| 2023 | 74m |
| 2024 | 75m |
| 2025 | 76m |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
Average daily flow
| Year | Vehicles a day |
|---|---|
| 2000 | 13,761 |
| 2001 | 14,233 |
| 2002 | 14,126 |
| 2003 | 14,752 |
| 2004 | 14,393 |
| 2005 | 14,318 |
| 2006 | 13,311 |
| 2007 | 14,020 |
| 2008 | 14,585 |
| 2009 | 14,455 |
| 2010 | 14,119 |
| 2011 | 14,187 |
| 2012 | 13,806 |
| 2013 | 13,925 |
| 2014 | 14,372 |
| 2015 | 14,680 |
| 2016 | 15,034 |
| 2017 | 15,161 |
| 2018 | 15,041 |
| 2019 | 14,264 |
| 2020 | 10,847 |
| 2021 | 11,906 |
| 2022 | 12,468 |
| 2023 | 12,562 |
| 2024 | 12,725 |
| 2025 | 12,914 |
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 (88.2% 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.
A340 collisions
Police recorded 111 collisions with the A340 as the first road from 2021 to 2025, 27 of them fatal or serious. That is 30.2 per 100 million vehicle miles, close to the 31.5 for all A-roads in Great Britain. On average there were 1.4 a year for each mile of road.
Reported collisions by year
About the same in 2025 as in 2021.
| Year | Slight | Fatal or serious |
|---|---|---|
| 2021 | 18 | 5 |
| 2022 | 17 | 4 |
| 2023 | 12 | 6 |
| 2024 | 22 | 4 |
| 2025 | 15 | 8 |
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 |
|---|---|
| Priestley Rd to A339 Hampshire · 15 collisions | 107.3 |
| A339 to A3010 Hampshire · 25 collisions | 63.0 |
| B3051 to Knapp Lane, Tadley West Berkshire, Hampshire · 14 collisions | 27.9 |
| A329 to A4 West Berkshire · 19 collisions | 27.5 |
| Knapp Lane, Tadley to Priestley Rd, Basingstoke Hampshire · 26 collisions | 24.0 |
Source:DfT STATS19,UK Motoring analysis 2021 to 2025 Updated
A further 27 collisions were recorded at junctions where the A340 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 A340
In route order. Each is the highway authority DfT files the count points under.
- West Berkshire
- Hampshire
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 | 111 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.