A-road

A331 traffic and collisions

The A331 is an A-road of 9.5 miles, in Surrey. This page covers its traffic at 17 DfT count points since 2000 and the collisions police recorded on it.

Last updated
Records analysed
17 count points in 2025
Methodology
View methodology
  • Traffic in 2025 199m vehicle miles
  • Average daily traffic 57,404 vehicles a day, both directions
  • Busiest section 70,159 A331 to A323
  • HGV share 2.9% of vehicle miles
  • Traffic since 2019 −1.4% same count points
  • Collisions, 2021 to 2025 92 10.1 per 100m vehicle miles

How busy is the A331?

On an average day in 2025, 57,404 vehicles passed each point on the A331, counting both directions. The busiest section is A331 to A323 (Hampshire, Surrey), with 70,159 a day; the quietest listed is A30 to M3 slip, with 32,432.

Busiest sections, 2025

A331 to A323 carries 1.2 times the road’s average flow.

Sections of the A331 with the highest average daily flow, 2025
Section Vehicles a day
A331 to A323 Hampshire, Surrey · 2.5 mi · HGVs 2.8% 70,159
A331 spur to A3011 Hampshire, Surrey · 2.4 mi · HGVs 2.7% 67,938
A3 to A331 Surrey · 1.5 mi · HGVs 3.1% 61,910
A30 to M3 slip Surrey, Hampshire · 1.3 mi · HGVs 2.3% 32,432

Source:DfT,UK Motoring analysis 2000 to 2025 Updated

Route

In Surrey · 9.5 miles

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

A331 traffic and collisions by section

8 sections between junctions, in route order. Each is the average of its DfT count points, weighted by length. 2 short link roads and spurs (0.5 miles) count in the road’s totals but are not listed.

Sections Tap a column heading to sort
Sections of the A331 in route order, 2025 traffic
#
1A30 to M3 slipSurrey, Hampshire1.332,4322.3%−1.1%2533.8
2At M3 spurSurrey0.446,6865.5%−21.2%13
3M3 spur to A325Surrey0.470,8063.3%+4.7%5
4A325 to A331Hampshire0.263,0303.1%+3.1%fewer than 3
5A331 spur to A3011Hampshire, Surrey2.467,9382.7%−2.5%186.3
6A331 to A323Hampshire, Surrey2.570,1592.8%+1.3%155.1
7A3 to A331Surrey1.561,9103.1%9
8A331 to Shepherd + Flock roundaboutSurrey0.39,1052.5%3

Vehicles a day is the average daily flow in 2025. “Since 2019” compares the same count points. Collisions are those with the A331 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.

A331 traffic by vehicle type

Cars and taxis make up 80.1% of the vehicle miles on the A331. HGVs account for 2.9%.

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 A331, by year
Year HGV share
2000 4.0%
2001 3.8%
2002 3.8%
2003 3.7%
2004 3.6%
2005 3.8%
2006 3.8%
2007 3.8%
2008 3.7%
2009 3.1%
2010 3.3%
2011 3.4%
2012 3.4%
2013 3.4%
2014 3.7%
2015 3.5%
2016 3.5%
2017 3.3%
2018 3.2%
2019 3.0%
2020 3.4%
2021 3.3%
2022 3.2%
2023 3.0%
2024 3.0%
2025 2.9%

Source:DfT,UK Motoring analysis 2000 to 2025 Updated

A331 traffic trend

Traffic on the A331 came to 199 million vehicle miles in 2025. At the count points present in both years, it is down 1.4% on 2019, before the pandemic, and up 5.6% on 2015.

Vehicle miles a year

Like for like, traffic is up 21.4% on 2000.

Vehicle miles on the A331 each year, the whole road as it was that year
Year Vehicle miles
2000 145m
2001 153m
2002 154m
2003 152m
2004 167m
2005 155m
2006 156m
2007 152m
2008 154m
2009 157m
2010 157m
2011 158m
2012 159m
2013 161m
2014 165m
2015 172m
2016 174m
2017 180m
2018 189m
2019 191m
2020 141m
2021 159m
2022 172m
2023 185m
2024 193m
2025 199m

Source:DfT,UK Motoring analysis 2000 to 2025 Updated

Average daily flow

Average daily flow along the A331, weighted by link length, by year
Year Vehicles a day
2000 49,739
2001 52,328
2002 52,741
2003 52,187
2004 57,282
2005 52,941
2006 53,578
2007 51,984
2008 52,620
2009 53,610
2010 51,916
2011 52,181
2012 52,322
2013 53,237
2014 54,311
2015 56,696
2016 57,377
2017 59,554
2018 60,105
2019 60,705
2020 45,052
2021 50,796
2022 54,682
2023 58,991
2024 61,459
2025 57,404

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 (77.9% of today’s road for 2019). In 2025, 10 of the 17 count points were counted; DfT estimated the rest from earlier counts and local trends.

A331 collisions

Police recorded 92 collisions with the A331 as the first road from 2021 to 2025, 20 of them fatal or serious. That is 10.1 per 100 million vehicle miles, lower than the 31.5 for all A-roads in Great Britain. On average there were 1.9 a year for each mile of road.

Reported collisions by year

Down 10.5% from 2021 to 2025.

Police-reported collisions on the A331 by year
Year Collisions
2021 19
2022 28
2023 13
2024 15
2025 17

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 A331, 2021 to 2025
Section Per 100m vehicle miles
A30 to M3 slip Surrey, Hampshire · 25 collisions 33.8
A331 spur to A3011 Hampshire, Surrey · 18 collisions 6.3
A331 to A323 Hampshire, Surrey · 15 collisions 5.1

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

A further 14 collisions were recorded at junctions where the A331 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 A331

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

  • Surrey
  • Hampshire

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 17 count points in 2025 15 September 2026
Reported collisions Road safety open data (STATS19) Department for Transport
Derived statistics UK Motoring
2021 to 2025 92 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.