Trunk A-road

A308 traffic and collisions

The A308 is a trunk A-road of 33.1 miles, from Kensington and Chelsea to Windsor and Maidenhead. 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 220m vehicle miles
Average daily traffic 18,201 vehicles a day, both directions
Busiest section 32,065 A309 to A311
HGV share 2.2% of vehicle miles
Traffic since 2019 −7.2% same count points
Collisions, 2021 to 2025 958 90.3 per 100m vehicle miles

How busy is the A308?

On an average day in 2025, 18,201 vehicles passed each point on the A308, counting both directions. The busiest section is A309 to A311 (Richmond upon Thames), with 32,065 a day; the quietest listed is A404 to Pinkneys Drive, Maidenhead, with 7,317.

Busiest sections, 2025

A309 to A311 carries 1.8 times the road’s average flow.

Sections of the A308 with the highest average daily flow, 2025
Section	Vehicles a day
A309 to A311 Richmond upon Thames · 1.0 mi · HGVs 1.8%	32,065
A308(M) Slip Road to A4 Castle Hill Windsor and Maidenhead · 1.5 mi · HGVs 2.9%	27,750
M3 to A244 Surrey · 0.6 mi · HGVs 2.6%	27,080
A328 to B3022 Windsor and Maidenhead · 2.5 mi · HGVs 1.7%	23,220
A244 to A30 Surrey · 3.4 mi · HGVs 4.7%	22,618
B3376 to A30 Surrey · 0.9 mi · HGVs 1.2%	22,238
A3220 to A217 Kensington and Chelsea, Hammersmith and Fulham · 0.6 mi · HGVs 2.4%	19,780
A310 to A309 Richmond upon Thames · 1.5 mi · HGVs 2.2%	19,643
M3 Junction 1 to M3 Surrey · 1.7 mi · HGVs 2.5%	18,488
A3220 to A4 Kensington and Chelsea · 1.2 mi · HGVs 1.3%	18,203

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

Route

Kensington and Chelsea to Windsor and Maidenhead · 33.1 miles

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

A308 traffic and collisions by section

33 sections between junctions, in route order. Each is the average of its DfT count points, weighted by length. 3 short link roads and spurs (0.5 miles) count in the road’s totals but are not listed.

Show all 33 sections Tap a column heading to sort

Sections of the A308 in route order, 2025 traffic
#
1	A3220 to A4Kensington and Chelsea	1.2	18,203	1.3%	+1.8%	102	243.1
2	A3220 Gunter Grove to A3220 Edith GroveKensington and Chelsea	0.1	18,203	1.3%	+1.8%	20	–
3	A3220 to A217Kensington and Chelsea, Hammersmith and Fulham	0.6	19,780	2.4%	−30.3%	147	579.3
4	A217 to A219Hammersmith and Fulham	0.9	13,898	2.7%	+1.2%	74	325.8
5	A3 to A238Kingston upon Thames	2.3	11,442	0.7%	−16.0%	46	93.7
6	A238 to A2043Kingston upon Thames	0.1	20,742	1.0%	+0.4%	19	–
7	A2043 to A307Kingston upon Thames	0.2	20,737	2.6%	+25.2%	12	–
8	A307 Richmond Rd/Eden St to A307 Fairfield North/London RdKingston upon Thames	0.3	27,201	1.3%	−12.5%	27	–
9	A307 Richmond Rd to Kingsgate RdKingston upon Thames	0.1	24,454	1.4%	−14.6%	12	–
10	Kingsgate Rd to Horse FairKingston upon Thames	0.3	35,582	1.1%	−16.3%	15	–
11	Horse Fair to A310Richmond upon Thames	0.1	35,582	1.1%	−16.3%	11	–
12	A310 to A309Richmond upon Thames	1.5	19,643	2.2%	+10.2%	40	82.3
13	A309 to A311Richmond upon Thames	1.0	32,065	1.8%	−4.8%	38	67.2
14	A311 to A3008Richmond upon Thames	0.1	20,247	2.6%	−5.3%	7	–
15	A3008 to Lower Sunbury RdRichmond upon Thames	0.2	17,847	1.6%	−11.5%	fewer than 3	–
16	Lower Sunbury rd to M3 Junction 1Richmond upon Thames	0.8	16,149	3.2%	–	7	–
17	M3 Junction 1 to M3Surrey	1.7	18,488	2.5%	−3.8%	24	43.2
18	M3 to A244Surrey	0.6	27,080	2.6%	−17.8%	25	84.6
19	A244 to A30Surrey	3.4	22,618	4.7%	−15.7%	77	61.9
20	A30 to South StSurrey	0.4	12,709	1.2%	−13.8%	30	–
21	B376 to High StSurrey	0.3	9,179	0.9%	−7.0%	3	–
22	B376/A308 South st to A308 High StSurrey	0.2	18,019	0.5%	−1.2%	13	–
23	B376 to B3376Surrey	0.2	20,965	0.3%	−6.1%	26	–
24	B3376 to A30Surrey	0.9	22,238	1.2%	+8.3%	30	89.0
25	A30 to A328Surrey	1.9	15,051	1.0%	+6.8%	20	39.9
26	A328 to B3022Windsor and Maidenhead	2.5	23,220	1.7%	–	25	24.5
27	B3022 to A332 roundaboutWindsor and Maidenhead	0.5	15,578	1.5%	−5.8%	3	–
28	A308 Goslar Way to B3022 NorthWindsor and Maidenhead	0.2	12,773	1.2%	−6.0%	fewer than 3	–
29	B3024/B3175 to Osborne Rd/Alma RdWindsor and Maidenhead	0.4	22,951	1.4%	−5.0%	fewer than 3	–
30	Roundabout A308/Maidenhead Road to A308(M) Slip RoadWindsor and Maidenhead	4.3	14,974	1.4%	–	48	50.4
31	A308(M) Slip Road to A4 Castle HillWindsor and Maidenhead	1.5	27,750	2.9%	–	25	41.7
32	Pinkneys Drive to A4Windsor and Maidenhead	1.9	12,134	2.6%	−2.2%	11	29.1
33	A404 to Pinkneys Drive, MaidenheadWindsor and Maidenhead	1.9	7,317	3.6%	−5.5%	8	–

Vehicles a day is the average daily flow in 2025. “Since 2019” compares the same count points. Collisions are those with the A308 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.

A308 traffic by vehicle type

Cars and taxis make up 81.3% of the vehicle miles on the A308. HGVs account for 2.2%, rising to 4.7% on A244 to A30.

Vehicle mix, 2025

Share of vehicle miles on the A308 by vehicle type
Category	Share
Cars and taxis	81.3%
Vans (LGVs)	13.2%
HGVs	2.2%
Motorcycles	2.2%
Buses and coaches	1.1%

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 A308, by year
Year	HGV share
2000	2.7%
2001	2.9%
2002	2.7%
2003	2.7%
2004	2.8%
2005	2.7%
2006	2.7%
2007	2.7%
2008	2.6%
2009	2.5%
2010	2.5%
2011	2.5%
2012	2.7%
2013	2.8%
2014	2.6%
2015	2.5%
2016	2.4%
2017	2.4%
2018	2.4%
2019	2.2%
2020	2.5%
2021	2.4%
2022	2.5%
2023	2.3%
2024	2.2%
2025	2.2%

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

A308 traffic trend

Traffic on the A308 came to 220 million vehicle miles in 2025. At the count points present in both years, it is down 7.2% on 2019, before the pandemic, and down 11.9% on 2015.

Vehicle miles a year

Like for like, traffic is down 24.1% on 2000.

Vehicle miles on the A308 each year, the whole road as it was that year
Year	Vehicle miles
2000	280m
2001	273m
2002	277m
2003	273m
2004	270m
2005	268m
2006	271m
2007	270m
2008	260m
2009	251m
2010	250m
2011	250m
2012	243m
2013	244m
2014	248m
2015	243m
2016	242m
2017	237m
2018	239m
2019	234m
2020	177m
2021	196m
2022	213m
2023	215m
2024	216m
2025	220m

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

Average daily flow

Average daily flow along the A308, weighted by link length, by year
Year	Vehicles a day
2000	22,848
2001	22,283
2002	22,573
2003	22,418
2004	22,114
2005	21,996
2006	22,229
2007	22,122
2008	21,328
2009	20,585
2010	20,529
2011	20,528
2012	19,966
2013	20,037
2014	20,322
2015	20,377
2016	20,308
2017	19,860
2018	19,696
2019	19,457
2020	14,606
2021	16,212
2022	17,648
2023	17,831
2024	17,887
2025	18,201

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 (72.5% of today’s road for 2019). In 2025, 11 of the 37 count points were counted; DfT estimated the rest from earlier counts and local trends.

A308 collisions

Police recorded 958 collisions with the A308 as the first road from 2021 to 2025, 206 of them fatal or serious, including 5 fatal. That is 90.3 per 100 million vehicle miles, higher than the 31.5 for all A-roads in Great Britain. On average there were 5.8 a year for each mile of road.

Reported collisions by year

Down 25.1% 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 A308, 2021 to 2025
Section	Per 100m vehicle miles
A3220 to A217 Kensington and Chelsea, Hammersmith and Fulham · 147 collisions	579.3
A217 to A219 Hammersmith and Fulham · 74 collisions	325.8
A3220 to A4 Kensington and Chelsea · 102 collisions	243.1
A3 to A238 Kingston upon Thames · 46 collisions	93.7
B3376 to A30 Surrey · 30 collisions	89.0
M3 to A244 Surrey · 25 collisions	84.6
A310 to A309 Richmond upon Thames · 40 collisions	82.3
A309 to A311 Richmond upon Thames · 38 collisions	67.2

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

A further 151 collisions were recorded at junctions where the A308 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 A308

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

Kensington and Chelsea
Hammersmith and Fulham
Kingston upon Thames
Richmond upon Thames
Surrey
Windsor and Maidenhead

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	958 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”.

How we calculate these figures All data sources

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

How busy is the A308?

Route

A308 traffic and collisions by section

A308 traffic by vehicle type

A308 traffic trend

A308 collisions

Council areas on the A308

Roads that meet the A308

Data sources and methodology

Related statistics