Trunk A-road

A339 traffic and collisions

The A339 is a trunk A-road of 33.6 miles, from Hampshire to West Berkshire. This page covers its traffic at 16 DfT count points since 2000 and the collisions police recorded on it.

Last updated
Records analysed
16 count points in 2025
Methodology
View methodology
  • Traffic in 2025 244m vehicle miles
  • Average daily traffic 19,864 vehicles a day, both directions
  • Busiest section 62,130 A3010 to A33
  • HGV share 4.3% of vehicle miles
  • Traffic since 2019 −2.1% same count points
  • Collisions, 2021 to 2025 221 20.6 per 100m vehicle miles

How busy is the A339?

On an average day in 2025, 19,864 vehicles passed each point on the A339, counting both directions. The busiest section is A3010 to A33 (Hampshire), with 62,130 a day; the quietest listed is B3349 Basingstoke Rd, Alton to Grove Rd, Basingstoke, with 9,672.

Busiest sections, 2025

A3010 to A33 carries 3.1 times the road’s average flow.

Sections of the A339 with the highest average daily flow, 2025
Section Vehicles a day
A3010 to A33 Hampshire · 1.0 mi · HGVs 3.7% 62,130
A33 to A340 Hampshire · 1.6 mi · HGVs 3.5% 46,593
A340 Ringway West to A340 Aldermaston Road Hampshire · 0.6 mi · HGVs 2.1% 41,796
A343 to A4 intersection West Berkshire · 0.9 mi · HGVs 2.4% 41,781
PINCHINGTON LANE to A343 West Berkshire · 0.8 mi · HGVs 3.6% 26,198
B4640 to PINCHINGTON LANE West Berkshire · 0.9 mi · HGVs 5.0% 25,636
A4 intersection to A34 West Berkshire · 2.3 mi · HGVs 5.9% 24,059
A340 to Roman Rd Hampshire · 0.6 mi · HGVs 5.3% 19,616
Roman Rd, Basingstoke to B3051 Hampshire · 7.1 mi · HGVs 5.3% 17,672
B3051 to Old A34 Hampshire, West Berkshire · 5.7 mi · HGVs 6.4% 15,479

Source:DfT,UK Motoring analysis 2000 to 2025 Updated

Route

Hampshire to West Berkshire · 33.6 miles

Hampshire West Berkshire
Schematic route: each line joins the junctions at the ends of a DfT count point link.

A339 traffic and collisions by section

15 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 A339 in route order, 2025 traffic
#
1A31 to Butts LaneHampshire0.511,6472.3%+3.9%8
2B3349 Basingstoke Rd to Butts RdHampshire0.612,7992.3%+3.9%3
3B3349 Basingstoke Rd, Alton to Grove Rd, BasingstokeHampshire10.49,6723.0%−6.3%3519.9
4Grove Rd to A30Hampshire0.210,7363.0%−6.3%fewer than 3
5A30 to A3010Hampshire0.467,4713.4%−0.6%18
6A3010 to A33Hampshire1.062,1303.7%1357.3
7A33 to A340Hampshire1.646,5933.5%8
8A340 Ringway West to A340 Aldermaston RoadHampshire0.641,7962.1%+1.5%1125.2
9A340 to Roman RdHampshire0.619,6165.3%+1.7%7
10Roman Rd, Basingstoke to B3051Hampshire7.117,6725.3%+1.7%3518.1
11B3051 to Old A34Hampshire, West Berkshire5.715,4796.4%−7.7%3522.7
12B4640 to PINCHINGTON LANEWest Berkshire0.925,6365.0%fewer than 3
13PINCHINGTON LANE to A343West Berkshire0.826,1983.6%+8.2%9
14A343 to A4 intersectionWest Berkshire0.941,7812.4%+2.9%2131.8
15A4 intersection to A34West Berkshire2.324,0595.9%−3.9%9

Vehicles a day is the average daily flow in 2025. “Since 2019” compares the same count points. Collisions are those with the A339 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.

A339 traffic by vehicle type

Cars and taxis make up 78.5% of the vehicle miles on the A339. HGVs account for 4.3%, rising to 6.4% on B3051 to Old A34.

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 A339, by year
Year HGV share
2000 5.5%
2001 5.5%
2002 5.2%
2003 5.2%
2004 5.1%
2005 5.0%
2006 4.9%
2007 5.2%
2008 4.9%
2009 4.5%
2010 4.8%
2011 4.8%
2012 4.9%
2013 4.8%
2014 4.7%
2015 4.7%
2016 4.5%
2017 4.6%
2018 4.5%
2019 4.5%
2020 5.6%
2021 5.5%
2022 5.0%
2023 4.8%
2024 4.4%
2025 4.3%

Source:DfT,UK Motoring analysis 2000 to 2025 Updated

A339 traffic trend

Traffic on the A339 came to 244 million vehicle miles in 2025. At the count points present in both years, it is down 2.1% on 2019, before the pandemic, and down 0.5% on 2015.

Vehicle miles a year

Like for like, traffic is up 5.7% on 2000.

Vehicle miles on the A339 each year, the whole road as it was that year
Year Vehicle miles
2000 213m
2001 214m
2002 215m
2003 221m
2004 225m
2005 227m
2006 229m
2007 225m
2008 232m
2009 230m
2010 225m
2011 227m
2012 224m
2013 219m
2014 225m
2015 226m
2016 230m
2017 227m
2018 235m
2019 237m
2020 170m
2021 187m
2022 204m
2023 211m
2024 230m
2025 244m

Source:DfT,UK Motoring analysis 2000 to 2025 Updated

Average daily flow

Average daily flow along the A339, weighted by link length, by year
Year Vehicles a day
2000 17,437
2001 17,514
2002 17,617
2003 18,100
2004 18,394
2005 18,536
2006 18,760
2007 18,416
2008 18,993
2009 18,821
2010 18,410
2011 18,522
2012 18,321
2013 17,926
2014 18,399
2015 18,749
2016 18,775
2017 18,852
2018 19,252
2019 19,585
2020 14,057
2021 15,541
2022 16,911
2023 17,527
2024 19,084
2025 19,864

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 (89.6% of today’s road for 2019). In 2025, 3 of the 16 count points were counted; DfT estimated the rest from earlier counts and local trends.

A339 collisions

Police recorded 221 collisions with the A339 as the first road from 2021 to 2025, 64 of them fatal or serious, including 6 fatal. That is 20.6 per 100 million vehicle miles, lower than the 31.5 for all A-roads in Great Britain. On average there were 1.3 a year for each mile of road.

Reported collisions by year

Down 24.4% from 2021 to 2025.

Police-reported collisions on the A339 by year: fatal or serious, and slight
Year SlightFatal or serious
2021 3312
2022 3211
2023 3317
2024 3811
2025 2113

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 A339, 2021 to 2025
Section Per 100m vehicle miles
A3010 to A33 Hampshire · 13 collisions 57.3
A343 to A4 intersection West Berkshire · 21 collisions 31.8
A340 Ringway West to A340 Aldermaston Road Hampshire · 11 collisions 25.2
B3051 to Old A34 Hampshire, West Berkshire · 35 collisions 22.7
B3349 Basingstoke Rd, Alton to Grove Rd, Basingstoke Hampshire · 35 collisions 19.9
Roman Rd, Basingstoke to B3051 Hampshire · 35 collisions 18.1

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

A further 31 collisions were recorded at junctions where the A339 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 A339

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

  • Hampshire
  • West Berkshire

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 16 count points in 2025 15 September 2026
Reported collisions Road safety open data (STATS19) Department for Transport
Derived statistics UK Motoring
2021 to 2025 221 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.