Trunk A-road

A40 traffic and collisions

The A40 is a trunk A-road of 271.4 miles in England and Wales, from City of London to Pembrokeshire. This page covers its traffic at 148 DfT count points since 2000 and the collisions police recorded on it.

Last updated: 15 September 2026
Data source: Department for Transport
Records analysed: 148 count points in 2025
Methodology: View methodology

Traffic in 2025 1.9bn vehicle miles
Average daily traffic 19,524 vehicles a day, both directions
Busiest section 116,530 A406(T) to A4127
HGV share 5.3% of vehicle miles
Traffic since 2019 −1.4% same count points
Collisions, 2021 to 2025 2,091 22.6 per 100m vehicle miles

How busy is the A40?

On an average day in 2025, 19,524 vehicles passed each point on the A40, counting both directions. The busiest section is A406(T) to A4127 (Ealing), with 116,530 a day; the quietest listed is A40 to A487, with 3,140.

Busiest sections, 2025

A406(T) to A4127 carries 6.0 times the road’s average flow.

Sections of the A40 with the highest average daily flow, 2025
Section	Vehicles a day
A406(T) to A4127 Ealing · 2.7 mi · HGVs 4.3%	116,530
A4127 to A312 Ealing · 1.4 mi · HGVs 4.5%	112,934
A4180 to A437 Hillingdon · 1.9 mi · HGVs 4.5%	111,249
A437 slip Hillingdon · 0.7 mi · HGVs 4.2%	105,476
M40 J1 to B483/B467 Buckinghamshire · 0.5 mi · HGVs 5.0%	97,521
A312 Church Rd to A4180 Ealing, Hillingdon · 1.0 mi · HGVs 4.4%	96,666
A437 Western Avenue to A437 slip Hillingdon · 0.7 mi · HGVs 4.2%	89,655
slip roads to A219 to A4000 Hammersmith and Fulham, Ealing · 1.6 mi · HGVs 4.4%	73,179
A4206 to M41 Westminster, Kensington and Chelsea · 2.3 mi · HGVs 2.0%	68,498
A4013 to B4063 Gloucestershire · 0.6 mi · HGVs 1.8%	59,132

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

Route

City of London to Pembrokeshire · 271.4 miles

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

A40 traffic and collisions by section

119 sections between junctions, in route order. Each is the average of its DfT count points, weighted by length. 19 short link roads and spurs (5.2 miles) count in the road’s totals but are not listed.

Show all 119 sections Tap a column heading to sort

Sections of the A40 in route order, 2025 traffic
#
1	Newgate St to A1City of London	0.2	9,778	3.1%	−6.0%	7	–
2	A4208 to Edward StCity of London	0.4	17,905	2.3%	−31.7%	23	–
3	Edward St to Holborn CircusCity of London	0.2	19,201	2.5%	−30.0%	9	–
4	Gray's Inn Rd to Procter StCamden	0.3	11,299	4.1%	−33.8%	27	–
5	Procter St to KingswayCamden	0.1	11,316	3.1%	−23.8%	10	–
6	Kingsway to Southampton PlaceCamden	0.1	10,651	3.1%	−15.3%	fewer than 3	–
7	Southampton Place to Shaftesbury AveCamden	0.2	8,929	2.7%	−10.7%	6	–
8	Shaftesbury Ave to Charing Cross RoadCamden	0.1	4,621	4.6%	−10.5%	12	–
9	Charing Cross Road to Earnshaw StCamden	0.1	10,425	3.5%	−10.6%	33	–
10	A4201 to Great Portland StWestminster	0.4	10,867	2.1%	+6.2%	80	–
11	Great Portland St to Regent StWestminster	0.1	10,867	2.1%	+6.2%	25	–
12	Regent St to Orchard StWestminster	0.5	8,227	0.5%	−14.6%	95	1,272.8
13	At A41Westminster	0.1	6,547	0.7%	−45.5%	8	–
14	Marble Arch to A41 Portman StWestminster	0.2	8,214	2.5%	−12.9%	51	–
15	A4206 to M41Westminster, Kensington and Chelsea	2.3	68,498	2.0%	−16.6%	40	13.7
16	M41 to A219Kensington and Chelsea, Hammersmith and Fulham	0.3	70,785	5.5%	−18.5%	18	–
17	A219 to A40Hammersmith and Fulham	0.1	70,785	5.5%	−18.5%	6	–
18	slip roads to A219 to A4000Hammersmith and Fulham, Ealing	1.6	73,179	4.4%	−17.7%	95	43.3
19	At A4000Ealing	0.1	86,305	4.5%	+14.0%	10	–
20	A4000 to A406(T)Ealing	1.6	57,181	4.8%	−25.0%	67	35.7
21	A406(T) to A4127Ealing	2.7	116,530	4.3%	–	91	79.2
22	A4127 to A312Ealing	1.4	112,934	4.5%	−13.6%	70	24.0
23	A312 Church Rd to A4180Ealing, Hillingdon	1.0	96,666	4.4%	−9.9%	35	19.9
24	A4180 to A437Hillingdon	1.9	111,249	4.5%	–	39	50.6
25	A437 slip to A437 Western AvenueHillingdon	0.4	97,504	2.8%	+2.3%	fewer than 3	–
26	A437 Western Avenue to A437 slipHillingdon	0.7	89,655	4.2%	+0.9%	10	9.3
27	A437 slipHillingdon	0.7	105,476	4.2%	–	24	19.0
28	Council boundary to B467 slipsHillingdon	0.1	104,283	7.9%	–	4	–
29	M40 J1 to B483/B467Buckinghamshire	0.5	97,521	5.0%	−8.8%	9	–
30	M40 to A412Buckinghamshire	0.3	19,504	5.0%	−8.8%	10	–
31	A412 to M40 jn1/A412Buckinghamshire	0.7	39,450	4.3%	−11.5%	13	25.8
32	A412 to A413Buckinghamshire	0.8	31,344	3.6%	+10.9%	5	–
33	A413 to Fulmer Rd, Gerrards CrossBuckinghamshire	2.2	11,693	2.9%	−1.9%	10	22.3
34	Fulmer Rd to B416Buckinghamshire	0.4	11,171	2.4%	−5.5%	4	–
35	B416 to Bulstrode WayBuckinghamshire	0.4	20,981	2.7%	+5.9%	6	–
36	A355 to Bulstrode Way, Gerrards CrossBuckinghamshire	2.9	18,902	2.7%	+5.9%	16	17.5
37	Loudwater to Roundabout A355/A40Buckinghamshire	3.5	15,085	1.6%	–	30	40.2
38	A4094 to Station RdBuckinghamshire	0.4	22,480	1.6%	−1.6%	3	–
39	Station Rd to Abbey WayBuckinghamshire	2.5	25,495	1.0%	+2.9%	50	43.4
40	A404 to A40 London RoadBuckinghamshire	0.4	23,488	1.5%	−28.8%	4	–
41	A4128 to A404 intersectionBuckinghamshire	0.3	23,829	1.3%	−3.2%	16	–
42	A4218 to A4010Buckinghamshire	1.4	13,492	1.1%	−4.8%	36	108.1
43	At A4010Buckinghamshire	0.6	23,721	2.6%	+14.0%	fewer than 3	–
44	A4010 to Chipps HillBuckinghamshire	1.7	7,330	3.5%	−17.6%	6	–
45	Chipps Hill to B482Buckinghamshire	3.0	6,782	2.8%	−10.5%	8	–
46	B482 Marlow Rd to M40Buckinghamshire	0.7	11,595	3.1%	+29.7%	7	–
47	M40 to A329 MILTON COMMONBuckinghamshire, Oxfordshire	8.2	5,850	2.1%	+4.8%	18	22.9
48	A418 to M40/A329Oxfordshire	1.6	3,302	5.5%	−4.9%	fewer than 3	–
49	M40 spur/A40 to M40Oxfordshire	0.8	17,886	6.4%	−3.2%	3	–
50	A4142 Oxford Green Road Rnbt to A418Oxfordshire	4.4	33,664	5.1%	–	34	62.9
51	A420 to A4165Oxfordshire	3.8	36,849	3.2%	+6.8%	24	9.1
52	A4165 to A4144Oxfordshire	0.5	26,765	3.8%	+4.0%	9	–
53	A44 to B4449Oxfordshire	3.9	23,773	8.0%	−3.9%	27	16.2
54	B4449 to B4022Oxfordshire	3.6	30,395	5.3%	+1.8%	28	15.0
55	A415 WITNEY to B4022 Junction WITNEYOxfordshire	2.1	27,608	6.4%	+6.5%	5	–
56	B4047 to A415Oxfordshire	4.1	15,769	7.3%	−0.9%	9	–
57	A361 to B4047 roundaboutOxfordshire	2.7	21,668	4.8%	−2.3%	13	12.9
58	A361 Roundabout BURFORD to A429Oxfordshire, Gloucestershire	9.2	11,301	6.0%	+5.2%	34	19.7
59	A429 to A346Gloucestershire	5.8	12,278	6.8%	+2.5%	19	15.4
60	At A436Gloucestershire	0.9	5,133	3.8%	−6.1%	3	–
61	At A436Gloucestershire	0.1	4,619	3.8%	−6.1%	fewer than 3	–
62	A436 to East End Rd, CheltenhamGloucestershire	3.7	8,320	2.6%	−6.8%	16	29.6
63	East End Rd to A435Gloucestershire	1.1	10,736	1.5%	−5.6%	7	–
64	A435 to Sandford Mill RdGloucestershire	0.2	16,572	2.1%	−5.5%	6	–
65	A40/ Old Bath Road to London RdGloucestershire	0.2	3,487	1.8%	−5.8%	0	–
66	Sandford Road to Sandford MillGloucestershire	0.1	14,318	2.0%	−5.9%	0	–
67	A46 Bath Road to A46 Sandford RoadGloucestershire	0.6	10,636	1.3%	−5.8%	4	–
68	A46 to A40SplitGloucestershire	0.6	11,327	1.3%	−5.8%	8	–
69	A40 SPLIT to A4013Gloucestershire	1.3	24,988	1.3%	+2.6%	32	56.6
70	A4013 to B4063Gloucestershire	0.6	59,132	1.8%	+13.7%	11	18.6
71	B4063 to M5 JN11Gloucestershire	0.7	53,272	1.8%	–	16	117.6
72	M5 - J11 to B4063Gloucestershire	2.4	39,621	2.5%	+23.2%	32	19.5
73	B4063 to A38Gloucestershire	1.9	30,833	3.7%	+30.1%	26	25.2
74	A430 to A417Gloucestershire	1.2	29,263	4.6%	+4.3%	10	16.4
75	A417 to A48Gloucestershire	1.6	43,781	3.0%	+10.7%	20	16.4
76	A48 to A4136Gloucestershire	5.1	11,061	5.4%	−12.2%	16	15.2
77	A4136 to Council boundaryGloucestershire	3.4	3,322	4.5%	−11.0%	5	–
78	Count point 92208Herefordshire	0.2	4,125	6.2%	–	0	–
79	A449Herefordshire	5.5	3,818	5.8%	–	11	29.8
80	A449 to A49Herefordshire	1.6	31,696	10.8%	+11.5%	9	–
81	A49 to A4137Herefordshire	5.1	24,305	12.2%	−1.5%	11	4.9
82	A4137 to A466Herefordshire, Monmouthshire	4.3	29,358	14.7%	−0.8%	12	5.5
83	A466 Wyebridge St to A466 Dixton Road roundaboutMonmouthshire	0.7	37,549	11.7%	−4.2%	3	–
84	B4293 to A466Monmouthshire	0.5	34,755	10.7%	−1.9%	0	–
85	B4233 to A449Monmouthshire	6.1	27,338	13.0%	−5.7%	14	4.6
86	A449 to A465Monmouthshire	9.0	17,085	7.6%	+26.5%	13	5.3
87	A465 to Gobanniun WayMonmouthshire	0.2	14,248	1.3%	+1.7%	fewer than 3	–
88	Gobanniun Way to A4143Monmouthshire	1.6	15,657	1.3%	+1.7%	6	–
89	A4143 to Pentre RdMonmouthshire	0.7	7,899	3.6%	−39.1%	4	–
90	Pentre Rd, Abergavenny to A4077Monmouthshire, Powys	5.1	8,104	3.3%	+2.4%	14	19.7
91	A4077 to A479Powys	1.6	9,236	3.5%	−4.9%	3	–
92	A479 to B4560SPowys	3.3	5,807	3.1%	−10.6%	fewer than 3	–
93	B4560S to B4560NPowys	0.9	6,641	6.2%	+0.2%	fewer than 3	–
94	B4560N to A470NPowys	6.5	5,542	3.1%	+9.5%	20	35.3
95	A470N to A470SPowys	2.7	9,190	6.6%	−4.3%	8	–
96	A470S to A4067Powys	7.5	5,989	4.4%	+10.9%	15	20.2
97	A4067 to A4069Powys, Carmarthenshire	12.2	3,527	7.7%	−2.6%	34	45.4
98	A4069 to A483Carmarthenshire	0.2	5,555	3.8%	−4.1%	3	–
99	A483 to A482Carmarthenshire	3.9	6,095	5.1%	−4.9%	11	26.4
100	A482 to A4069Carmarthenshire	2.5	5,269	6.5%	+0.1%	4	–
101	A4069 to A483Carmarthenshire	5.6	6,993	5.4%	−5.1%	10	14.5
102	A483 to B4297Carmarthenshire	5.1	5,354	4.3%	+5.0%	13	29.6
103	B4297 to B4130Carmarthenshire	4.5	5,138	8.5%	+1.2%	7	–
104	B4130 to A485Carmarthenshire	4.0	7,975	3.5%	−5.2%	14	25.2
105	A485 to A484Carmarthenshire	1.6	18,566	3.5%	−11.1%	5	–
106	A48 to A40Carmarthenshire	0.6	21,327	3.5%	+13.0%	5	–
107	A4242 to A484Carmarthenshire	0.6	39,755	4.4%	+4.5%	17	42.0
108	A48 to A4066Carmarthenshire	8.5	43,969	4.7%	+4.0%	28	4.4
109	A4066 to A477 / A4066Carmarthenshire	0.4	26,203	5.1%	+39.7%	fewer than 3	–
110	A477 / A4066 to B4328Carmarthenshire	4.0	12,885	7.0%	+3.2%	15	17.1
111	B4328 to A478Carmarthenshire, Pembrokeshire	6.1	11,362	8.0%	–	20	37.4
112	A478 to A4075Pembrokeshire	3.5	11,330	7.8%	–	5	–
113	A4075 to A4076Pembrokeshire	7.2	14,265	6.8%	−6.3%	25	13.9
114	A4076 to A40 splitPembrokeshire	1.2	11,961	5.1%	+13.9%	6	–
115	A40 split to B4331Pembrokeshire	8.2	10,835	3.6%	+5.1%	28	18.4
116	B4331 to A4219Pembrokeshire	3.7	7,216	2.9%	+5.5%	12	25.8
117	A4219 to A40Pembrokeshire	1.2	6,336	4.5%	−4.8%	8	–
118	A40 to A487Pembrokeshire	0.7	3,140	3.6%	−5.2%	0	–
119	At A487Pembrokeshire	0.6	6,395	2.1%	−11.9%	0	–

Vehicles a day is the average daily flow in 2025. “Since 2019” compares the same count points. Collisions are those with the A40 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.

A40 traffic by vehicle type

Cars and taxis make up 75.6% of the vehicle miles on the A40. HGVs account for 5.3%, rising to 14.7% on A4137 to A466.

Vehicle mix, 2025

Share of vehicle miles on the A40 by vehicle type
Category	Share
Cars and taxis	75.6%
Vans (LGVs)	17.2%
HGVs	5.3%
Motorcycles	1.3%
Buses and coaches	0.6%

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 A40, by year
Year	HGV share
2000	7.0%
2001	6.8%
2002	7.0%
2003	6.8%
2004	6.8%
2005	6.8%
2006	6.6%
2007	6.9%
2008	6.5%
2009	5.8%
2010	5.9%
2011	6.1%
2012	6.2%
2013	5.9%
2014	6.0%
2015	6.2%
2016	5.9%
2017	6.1%
2018	6.0%
2019	6.0%
2020	6.9%
2021	7.1%
2022	6.4%
2023	6.0%
2024	5.7%
2025	5.3%

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

A40 traffic trend

Traffic on the A40 came to 1.93 billion vehicle miles in 2025. At the count points present in both years, it is down 1.4% on 2019, before the pandemic, and up 2.6% on 2015.

Vehicle miles a year

Like for like, traffic is up 7.4% on 2000.

Vehicle miles on the A40 each year, the whole road as it was that year
Year	Vehicle miles
2000	1.8bn
2001	1.8bn
2002	1.8bn
2003	1.8bn
2004	1.8bn
2005	1.8bn
2006	1.8bn
2007	1.8bn
2008	1.8bn
2009	1.8bn
2010	1.8bn
2011	1.8bn
2012	1.7bn
2013	1.8bn
2014	1.8bn
2015	1.9bn
2016	1.9bn
2017	1.9bn
2018	2.0bn
2019	2.0bn
2020	1.5bn
2021	1.7bn
2022	1.9bn
2023	1.9bn
2024	1.9bn
2025	1.9bn

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

Average daily flow

Average daily flow along the A40, weighted by link length, by year
Year	Vehicles a day
2000	18,453
2001	18,484
2002	18,599
2003	18,758
2004	18,773
2005	18,622
2006	18,612
2007	18,262
2008	18,227
2009	18,401
2010	18,396
2011	18,056
2012	17,898
2013	18,717
2014	18,652
2015	18,999
2016	19,388
2017	19,808
2018	19,993
2019	19,752
2020	15,267
2021	16,913
2022	18,938
2023	18,971
2024	19,274
2025	19,524

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 (89.5% of today’s road for 2019). In 2025, 29 of the 148 count points were counted; DfT estimated the rest from earlier counts and local trends.

A40 collisions

Police recorded 2,091 collisions with the A40 as the first road from 2021 to 2025, 549 of them fatal or serious, including 39 fatal. That is 22.6 per 100 million vehicle miles, lower than the 31.5 for all A-roads in Great Britain. On average there were 1.5 a year for each mile of road.

Reported collisions by year

Up 16.6% 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 A40, 2021 to 2025
Section	Per 100m vehicle miles
Regent St to Orchard St Westminster · 95 collisions	1,272.8
B4063 to M5 JN11 Gloucestershire · 16 collisions	117.6
A4218 to A4010 Buckinghamshire · 36 collisions	108.1
A406(T) to A4127 Ealing · 91 collisions	79.2
A4142 Oxford Green Road Rnbt to A418 Oxfordshire · 34 collisions	62.9
A40 SPLIT to A4013 Gloucestershire · 32 collisions	56.6
A4180 to A437 Hillingdon · 39 collisions	50.6
A4067 to A4069 Powys, Carmarthenshire · 34 collisions	45.4

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

A further 288 collisions were recorded at junctions where the A40 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 A40

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

City of London
Camden
Westminster
Kensington and Chelsea
Hammersmith and Fulham
Ealing
Hillingdon
Buckinghamshire
Oxfordshire
Gloucestershire
Herefordshire
Monmouthshire
Powys
Carmarthenshire
Pembrokeshire

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	148 count points in 2025	15 September 2026
Reported collisions	Road safety open data (STATS19) Department for Transport Derived statistics UK Motoring	2021 to 2025	2,091 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 A40?

Route

A40 traffic and collisions by section

A40 traffic by vehicle type

A40 traffic trend

A40 collisions

Council areas on the A40

Roads that meet the A40

Data sources and methodology

Related statistics