Trunk A-road

A406 traffic and collisions

The A406 is a trunk A-road of 28.5 miles, from Hounslow to Newham. This page covers its traffic at 39 DfT count points since 2000 and the collisions police recorded on it.

Last updated: 15 September 2026
Data source: Department for Transport
Records analysed: 39 count points in 2025
Methodology: View methodology

Traffic in 2025 913m vehicle miles
Average daily traffic 87,764 vehicles a day, both directions
Busiest section 149,848 A104 to Southend Road (North Cicular Road)
HGV share 4.3% of vehicle miles
Traffic since 2019 −4.4% same count points
Collisions, 2021 to 2025 2,033 47.0 per 100m vehicle miles

How busy is the A406?

On an average day in 2025, 87,764 vehicles passed each point on the A406, counting both directions. The busiest section is A104 to Southend Road (North Cicular Road) (Waltham Forest, Redbridge), with 149,848 a day; the quietest listed is A4000 to A4020, with 25,788.

Busiest sections, 2025

A104 to Southend Road (North Cicular Road) carries 1.7 times the road’s average flow.

Sections of the A406 with the highest average daily flow, 2025
Section	Vehicles a day
A104 to Southend Road (North Cicular Road) Waltham Forest, Redbridge · 1.0 mi · HGVs 3.3%	149,848
A112 to A104 Waltham Forest · 1.4 mi · HGVs 3.7%	124,152
Centre point M11 Slip roads to A12 redbridge r/abt Redbridge · 0.7 mi · HGVs 5.0%	123,497
A118 to A124 Redbridge, Newham · 1.4 mi · HGVs 4.7%	119,681
A4088/A406 cross (near vicarage way) to A406 meets Waterloo Road Brent · 0.9 mi · HGVs 5.1%	116,726
A1009 to A112 Waltham Forest · 1.6 mi · HGVs 3.8%	115,439
A124 to A13 Newham · 0.9 mi · HGVs 5.5%	108,197
A1055 to A1009 Enfield, Waltham Forest · 1.1 mi · HGVs 3.8%	102,340
A404 to A4088 Brent · 1.5 mi · HGVs 4.4%	100,868
A1010 to A1055 Enfield · 0.5 mi · HGVs 3.2%	97,825

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

Route

Hounslow to Newham · 28.5 miles

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

A406 traffic and collisions by section

29 sections between junctions, in route order. Each is the average of its DfT count points, weighted by length. 5 short link roads and spurs (1.2 miles) count in the road’s totals but are not listed.

Show all 29 sections Tap a column heading to sort

Sections of the A406 in route order, 2025 traffic
#
1	A4/A205 to A4000Hounslow	0.7	38,994	3.2%	+5.5%	58	120.2
2	A4000 to A4020Ealing	0.8	25,788	3.9%	−17.3%	59	143.9
3	A4020 to A40Ealing	1.4	31,269	5.0%	−2.7%	117	152.9
4	A40 to A404Ealing, Brent	1.7	95,142	4.7%	–	107	67.7
5	A404 to A4088Brent	1.5	100,868	4.4%	−3.3%	171	62.2
6	A4088 (midpoint) to A4088 Neasden Lane NorthBrent	0.1	116,726	5.1%	+1.9%	8	–
7	A4088/A406 cross (near vicarage way) to A406 meets Waterloo RoadBrent	0.9	116,726	5.1%	+1.9%	51	28.0
8	A406 meets Waterloo Road to On A406 close to tilling road roundabout (parallel to Etheridge Road)Brent	0.8	77,661	4.8%	−7.0%	29	25.3
9	On A406 close to tilling road roundabout (parallel to Etheridge Road) to A406 north circular road meets A41 Brent Cross FlyoverBarnet	0.3	101,963	4.2%	−6.5%	22	–
10	A41 to A502Barnet	0.5	82,301	3.4%	+0.6%	30	41.0
11	A502 to A1Barnet	0.6	73,950	3.4%	−7.1%	51	61.7
12	A1 to A504Barnet	0.6	77,602	3.6%	−0.7%	89	110.6
13	A504 to A406 spurBarnet	0.6	76,190	3.8%	+1.3%	8	–
14	At A406 spurBarnet	0.2	73,959	3.7%	−3.1%	8	–
15	A406 spur to A109Barnet, Enfield	2.2	92,449	3.7%	–	80	94.0
16	A109 to A1110Enfield	0.4	44,375	5.0%	−9.2%	41	–
17	A1110 to A105Enfield	0.8	44,743	5.1%	−14.5%	89	125.9
18	A105 to A10(T)Enfield	1.1	66,025	4.2%	+7.4%	118	89.6
19	A10(T) to A1010Enfield	1.0	86,102	3.5%	−2.2%	92	59.1
20	A1010 to A1055Enfield	0.5	97,825	3.2%	+2.6%	28	32.8
21	A1055 to A1009Enfield, Waltham Forest	1.1	102,340	3.8%	−2.0%	68	33.1
22	A1009 to A112Waltham Forest	1.6	115,439	3.8%	–	70	103.8
23	A112 to A104Waltham Forest	1.4	124,152	3.7%	+2.6%	87	27.8
24	A104 to Southend Road (North Cicular Road)Waltham Forest, Redbridge	1.0	149,848	3.3%	+2.1%	40	14.5
25	M11 western end-spur to M11 eastern end-spur (mid-junction)Redbridge	0.8	61,218	5.7%	−32.1%	7	–
26	Centre point M11 Slip roads to A12 redbridge r/abtRedbridge	0.7	123,497	5.0%	−2.6%	64	41.8
27	A12 to A118Redbridge	1.7	97,129	5.3%	−16.7%	93	31.8
28	A118 to A124Redbridge, Newham	1.4	119,681	4.7%	−8.3%	128	42.4
29	A124 to A13Newham	0.9	108,197	5.5%	+2.4%	141	78.7

Vehicles a day is the average daily flow in 2025. “Since 2019” compares the same count points. Collisions are those with the A406 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.

A406 traffic by vehicle type

Cars and taxis make up 72.9% of the vehicle miles on the A406. HGVs account for 4.3%, rising to 5.7% on M11 western end-spur to M11 eastern end-spur (mid-junction).

Vehicle mix, 2025

Share of vehicle miles on the A406 by vehicle type
Category	Share
Cars and taxis	72.9%
Vans (LGVs)	20.4%
HGVs	4.3%
Motorcycles	1.9%
Buses and coaches	0.5%

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 A406, by year
Year	HGV share
2000	6.3%
2001	5.9%
2002	5.9%
2003	6.0%
2004	5.9%
2005	6.5%
2006	6.3%
2007	6.0%
2008	5.9%
2009	5.7%
2010	6.0%
2011	7.3%
2012	6.7%
2013	5.9%
2014	6.3%
2015	6.8%
2016	6.3%
2017	6.3%
2018	6.2%
2019	6.2%
2020	6.5%
2021	6.4%
2022	6.0%
2023	5.6%
2024	4.5%
2025	4.3%

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

A406 traffic trend

Traffic on the A406 came to 913 million vehicle miles in 2025. At the count points present in both years, it is down 4.4% on 2019, before the pandemic, and up 1.8% on 2015.

Vehicle miles a year

Like for like, traffic is up 20.7% on 2000.

Vehicle miles on the A406 each year, the whole road as it was that year
Year	Vehicle miles
2000	694m
2001	696m
2002	682m
2003	737m
2004	722m
2005	770m
2006	766m
2007	786m
2008	725m
2009	740m
2010	770m
2011	719m
2012	781m
2013	769m
2014	844m
2015	818m
2016	826m
2017	847m
2018	925m
2019	905m
2020	791m
2021	830m
2022	864m
2023	859m
2024	857m
2025	913m

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

Average daily flow

Average daily flow along the A406, weighted by link length, by year
Year	Vehicles a day
2000	73,651
2001	73,923
2002	72,386
2003	78,308
2004	76,704
2005	81,747
2006	81,297
2007	83,479
2008	77,024
2009	78,601
2010	81,718
2011	76,340
2012	82,880
2013	81,683
2014	89,654
2015	86,841
2016	85,027
2017	87,231
2018	92,508
2019	90,489
2020	79,052
2021	83,003
2022	86,389
2023	86,205
2024	85,992
2025	87,764

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 (83.9% of today’s road for 2019). In 2025, 25 of the 39 count points were counted; DfT estimated the rest from earlier counts and local trends.

A406 collisions

Police recorded 2,033 collisions with the A406 as the first road from 2021 to 2025, 257 of them fatal or serious, including 22 fatal. That is 47.0 per 100 million vehicle miles, higher than the 31.5 for all A-roads in Great Britain. On average there were 14.3 a year for each mile of road.

Reported collisions by year

Down 13.9% 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 A406, 2021 to 2025
Section	Per 100m vehicle miles
A4020 to A40 Ealing · 117 collisions	152.9
A4000 to A4020 Ealing · 59 collisions	143.9
A1110 to A105 Enfield · 89 collisions	125.9
A4/A205 to A4000 Hounslow · 58 collisions	120.2
A1 to A504 Barnet · 89 collisions	110.6
A1009 to A112 Waltham Forest · 70 collisions	103.8
A406 spur to A109 Barnet, Enfield · 80 collisions	94.0
A105 to A10(T) Enfield · 118 collisions	89.6

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

A further 473 collisions were recorded at junctions where the A406 was the second road; they are not in the figures above. Fatal or serious uses DfT’s adjusted serious figures. 96.1% of the collisions could be placed on a section. How we count collisions

Council areas on the A406

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

Hounslow
Ealing
Brent
Barnet
Enfield
Waltham Forest
Redbridge
Newham

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	39 count points in 2025	15 September 2026
Reported collisions	Road safety open data (STATS19) Department for Transport Derived statistics UK Motoring	2021 to 2025	2,033 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 A406?

Route

A406 traffic and collisions by section

A406 traffic by vehicle type

A406 traffic trend

A406 collisions

Council areas on the A406

Roads that meet the A406

Data sources and methodology

Related statistics