Trunk A-road

A31 traffic and collisions

The A31 is a trunk A-road of 74.4 miles, from Surrey to Dorset. This page covers its traffic at 37 DfT count points since 2000 and the collisions police recorded on it.

Last updated: 15 September 2026
Data source: Department for Transport
Records analysed: 37 count points in 2025
Methodology: View methodology

Traffic in 2025 865m vehicle miles
Average daily traffic 31,866 vehicles a day, both directions
Busiest section 97,149 A338 to B3081
HGV share 3.7% of vehicle miles
Traffic since 2019 +1.2% same count points
Collisions, 2021 to 2025 614 14.9 per 100m vehicle miles

How busy is the A31?

On an average day in 2025, 31,866 vehicles passed each point on the A31, counting both directions. The busiest section is A338 to B3081 (Hampshire), with 97,149 a day; the quietest listed is A36 to A337, with 4,597.

Busiest sections, 2025

A338 to B3081 carries 3.0 times the road’s average flow.

Sections of the A31 with the highest average daily flow, 2025
Section	Vehicles a day
A338 to B3081 Hampshire · 0.6 mi · HGVs 3.3%	97,149
M27 to A338 Hampshire · 10.4 mi · HGVs 3.9%	67,644
A348 Trickett's Cross Roundabout to Monks Close roundabout Dorset · 2.9 mi · HGVs 3.6%	54,775
A3 to A331 Surrey · 5.5 mi · HGVs 2.8%	48,208
Shepherd + Flock roundabout to B3001 Surrey · 0.8 mi · HGVs 3.6%	47,825
Shepherd + Flock roundabout to A331 Surrey · 1.3 mi · HGVs 2.5%	45,526
B3001 to A325 Surrey · 1.2 mi · HGVs 2.9%	37,003
Stapehill B3073 Canford Bottom Roundabout to A348 Trickett's Cross Roundabout Dorset · 3.5 mi · HGVs 4.9%	31,568
B3073 Canford Bottom Roundabout to A341 Dorset, Bournemouth, Christchurch and Poole · 2.2 mi · HGVs 4.5%	30,513
A331 to A3 Surrey · 0.6 mi · HGVs 2.5%	27,315

Source:DfT,UK Motoring analysis 2000 to 2025 Updated 15 Sept 2026

Route

Surrey to Dorset · 74.4 miles in 2 stretches

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

A31 traffic and collisions by section

31 sections between junctions, in route order (2 separate stretches). Each is the average of its DfT count points, weighted by length. 3 short link roads and spurs (0.4 miles) count in the road’s totals but are not listed.

Show all 31 sections Tap a column heading to sort

Sections of the A31 in route order, 2025 traffic
#
1	The Drive to A3100 / A281Surrey · stretch 1	0.9	14,597	2.4%	+6.9%	16	73.8
2	The Drive, Guildford to A3Surrey · stretch 1	1.0	14,590	1.5%	−4.9%	11	42.9
3	A3 to A331Surrey · stretch 1	5.5	48,208	2.8%	–	41	42.4
4	A331 to A3Surrey · stretch 1	0.6	27,315	2.5%	–	3	–
5	Shepherd + Flock roundabout to A331Surrey · stretch 1	1.3	45,526	2.5%	–	18	83.3
6	Farnham By-pass to Guildford RdSurrey · stretch 1	0.3	34,850	2.2%	−5.7%	7	–
7	Shepherd + Flock roundabout to B3001Surrey · stretch 1	0.8	47,825	3.6%	+3.9%	22	33.1
8	B3001 to A325Surrey · stretch 1	1.2	37,003	2.9%	−1.1%	16	20.6
9	A325 to B3004 roundaboutSurrey, Hampshire · stretch 1	7.3	19,501	3.6%	–	34	38.6
10	B3004 roundabout to A339Hampshire · stretch 1	2.2	16,938	4.2%	+2.5%	12	19.0
11	A339 to A32Hampshire · stretch 1	0.9	23,923	2.9%	+2.6%	9	–
12	A32 to Barn LaneHampshire · stretch 1	3.7	19,551	2.2%	+3.3%	24	19.6
13	Barn Lane to B3047Hampshire · stretch 1	3.0	11,811	3.4%	−12.8%	9	–
14	B3047 to B3047 Alresford RdHampshire · stretch 1	3.1	10,275	4.7%	−5.9%	4	–
15	B3047 to A272Hampshire · stretch 1	4.0	14,445	3.7%	−1.2%	18	18.1
16	At A272Hampshire · stretch 1	1.4	21,038	4.3%	−2.1%	10	20.6
17	A31 to M3 slipHampshire · stretch 1	0.6	15,475	3.5%	−14.3%	4	–
18	M3 slip to B3330/M3 slipHampshire · stretch 1	0.3	17,797	3.5%	−14.2%	8	–
19	A36 to A337Hampshire · stretch 2	2.6	4,597	1.7%	+37.2%	8	–
20	A337 to M27Hampshire · stretch 2	0.7	19,513	2.4%	–	4	–
21	M27 to A31Hampshire · stretch 2	0.3	13,529	3.9%	+1.5%	fewer than 3	–
22	M27 to A338Hampshire · stretch 2	10.4	67,644	3.9%	+1.5%	81	6.6
23	A338 to B3081Hampshire · stretch 2	0.6	97,149	3.3%	−1.6%	15	14.6
24	B3081 to B3081 (off)Dorset · stretch 2	0.3	86,374	3.4%	−10.0%	9	–
25	B3081 (off) to A338Dorset · stretch 2	0.3	86,374	3.4%	−10.0%	6	–
26	A348 Trickett's Cross Roundabout to Monks Close roundaboutDorset · stretch 2	2.9	54,775	3.6%	−0.1%	36	12.5
27	Monks Close roundabout to A338 Spur Road (roundabout)Dorset · stretch 2	0.4	51,962	3.9%	−6.2%	11	–
28	Stapehill B3073 Canford Bottom Roundabout to A348 Trickett's Cross RoundaboutDorset · stretch 2	3.5	31,568	4.9%	0.0%	53	28.1
29	B3073 Canford Bottom Roundabout to A341Dorset, Bournemouth, Christchurch and Poole · stretch 2	2.2	30,513	4.5%	−0.4%	29	23.1
30	A349 (roundabout) to A350Bournemouth, Christchurch and Poole, Dorset · stretch 2	4.5	24,188	5.3%	+20.5%	43	24.0
31	A35 Town's End Roundabout to A350 (roundabout)Dorset · stretch 2	7.2	19,898	3.9%	+6.4%	44	17.3

Vehicles a day is the average daily flow in 2025. “Since 2019” compares the same count points. Collisions are those with the A31 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.

A31 traffic by vehicle type

Cars and taxis make up 77.2% of the vehicle miles on the A31. HGVs account for 3.7%, rising to 5.3% on A349 (roundabout) to A350.

Vehicle mix, 2025

Share of vehicle miles on the A31 by vehicle type
Category	Share
Cars and taxis	77.2%
Vans (LGVs)	18.2%
HGVs	3.7%
Motorcycles	0.7%
Buses and coaches	0.2%

Source:DfT,UK Motoring analysis 2000 to 2025 Updated 15 Sept 2026

HGV share of traffic

HGVs as a share of vehicle miles on the A31, by year
Year	HGV share
2000	5.4%
2001	5.3%
2002	5.1%
2003	5.3%
2004	5.2%
2005	5.1%
2006	5.0%
2007	5.3%
2008	4.9%
2009	4.9%
2010	4.8%
2011	4.9%
2012	4.9%
2013	5.0%
2014	4.6%
2015	4.6%
2016	4.6%
2017	4.6%
2018	4.5%
2019	4.1%
2020	5.2%
2021	4.4%
2022	4.2%
2023	4.1%
2024	3.9%
2025	3.7%

Source:DfT,UK Motoring analysis 2000 to 2025 Updated 15 Sept 2026

A31 traffic trend

Traffic on the A31 came to 865 million vehicle miles in 2025. At the count points present in both years, it is up 1.2% on 2019, before the pandemic, and up 5.2% on 2015.

Vehicle miles a year

Like for like, traffic is up 17.8% on 2000.

Vehicle miles on the A31 each year, the whole road as it was that year
Year	Vehicle miles
2000	737m
2001	771m
2002	786m
2003	798m
2004	793m
2005	785m
2006	809m
2007	790m
2008	807m
2009	770m
2010	769m
2011	781m
2012	753m
2013	755m
2014	780m
2015	806m
2016	828m
2017	838m
2018	853m
2019	849m
2020	642m
2021	778m
2022	804m
2023	827m
2024	856m
2025	865m

Source:DfT,UK Motoring analysis 2000 to 2025 Updated 15 Sept 2026

Average daily flow

Average daily flow along the A31, weighted by link length, by year
Year	Vehicles a day
2000	27,700
2001	28,974
2002	29,552
2003	29,973
2004	29,784
2005	29,502
2006	30,408
2007	29,695
2008	30,312
2009	28,921
2010	28,916
2011	29,336
2012	28,303
2013	28,372
2014	29,305
2015	30,288
2016	31,103
2017	31,499
2018	31,367
2019	31,615
2020	23,900
2021	28,943
2022	29,916
2023	30,786
2024	31,856
2025	31,866

Source:DfT,UK Motoring analysis 2000 to 2025 Updated 15 Sept 2026

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 (81.0% of today’s road for 2019). In 2025, 12 of the 37 count points were counted; DfT estimated the rest from earlier counts and local trends.

A31 collisions

Police recorded 614 collisions with the A31 as the first road from 2021 to 2025, 163 of them fatal or serious, including 16 fatal. That is 14.9 per 100 million vehicle miles, lower than the 31.5 for all A-roads in Great Britain. On average there were 1.7 a year for each mile of road.

Reported collisions by year

Up 13.2% from 2021 to 2025.

Source:DfT STATS19,UK Motoring analysis 2021 to 2025 Updated 15 Sept 2026

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 A31, 2021 to 2025
Section	Per 100m vehicle miles
Shepherd + Flock roundabout to A331 Surrey · 18 collisions	83.3
The Drive to A3100 / A281 Surrey · 16 collisions	73.8
The Drive, Guildford to A3 Surrey · 11 collisions	42.9
A3 to A331 Surrey · 41 collisions	42.4
A325 to B3004 roundabout Surrey, Hampshire · 34 collisions	38.6
Shepherd + Flock roundabout to B3001 Surrey · 22 collisions	33.1
Stapehill B3073 Canford Bottom Roundabout to A348 Trickett's Cross Roundabout Dorset · 53 collisions	28.1
A349 (roundabout) to A350 Bournemouth, Christchurch and Poole, Dorset · 43 collisions	24.0

Source:DfT STATS19,UK Motoring analysis 2021 to 2025 Updated 15 Sept 2026

A further 41 collisions were recorded at junctions where the A31 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 A31

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

Surrey
Hampshire
Dorset
Bournemouth, Christchurch and Poole

Planned closures on the A31 in England

National Highways has 6 planned closures on the A31 between 16 September 2026 and 30 September 2026, all of them starting in that period. 2 close a carriageway rather than a lane or slip road, and 6 start between 7pm and 6am.

Lane or slip A31 eastbound lane 1 closure (27.0 - 26.2)

16 Sept 20:00 to 19 Sept 05:30 Authority operation
Lane or slip A31 eastbound lane 2 closure (20/7 to 19/2)

18 Sept 20:00 to 19 Sept 06:00 Road maintenance
Carriageway M27 eastbound Jct 1 to Jct 2 carriageway closure

22 Sept 21:00 to 23 Sept 06:00 Road maintenance Also affects M27
Lane or slip M27 eastbound lane 1 and 2 closure (5/6 to 6/6)

23 Sept 21:00 to 30 Sept 06:00 Road maintenance Also affects M27
Carriageway A31 westbound Verwood entry slip road closure

28 Sept 21:00 to 29 Sept 06:00 Road maintenance

1 more planned closure in this period are not shown.

Planned closures only: National Highways can cancel or change them, and closures caused by incidents are not shown. Council roads in England are not covered. Roadworks and closures across the UK

Source:National Highways 2026-09-16 to 2026-09-30 Updated 16 Sept 2026

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	37 count points in 2025	15 September 2026
Reported collisions	Road safety open data (STATS19) Department for Transport Derived statistics UK Motoring	2021 to 2025	614 reported collisions	15 September 2026
Planned closures	Transport Data Feeds (DATEX II) National Highways	2026-09-16 to 2026-09-30	2,304 planned closure schemes	16 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”.

How we calculate these figures All data sources

Contains public sector information licensed under the Open Government Licence v3.0.

How busy is the A31?

Route

A31 traffic and collisions by section

A31 traffic by vehicle type

A31 traffic trend

A31 collisions

Council areas on the A31

Roads that meet the A31

Planned closures on the A31 in England

Data sources and methodology

Related statistics