A-road
A4127 traffic and collisions
The A4127 is an A-road of 6.0 miles, from Brent to Ealing. This page covers its traffic at 7 DfT count points since 2000 and the collisions police recorded on it.
- Traffic in 2025 45m vehicle miles
- Average daily traffic 20,540 vehicles a day, both directions
- Busiest section 26,555 A4020 to A3005
- HGV share 3.8% of vehicle miles
- Traffic since 2019 −9.0% same count points
- Collisions, 2021 to 2025 224 99.2 per 100m vehicle miles
How busy is the A4127?
On an average day in 2025, 20,540 vehicles passed each point on the A4127, counting both directions. The busiest section is A4020 to A3005 (Ealing), with 26,555 a day; the quietest listed is A404 to A4005 Harrow Rd, with 14,558.
Busiest sections, 2025
A4020 to A3005 carries 1.3 times the road’s average flow.
| Section | Vehicles a day |
|---|---|
| A4020 to A3005 Ealing · 1.4 mi · HGVs 1.6% | 26,555 |
| A4090 to A40(T) Ealing · 1.4 mi · HGVs 7.1% | 22,600 |
| A4005 to A4090 Harrow, Ealing · 0.6 mi · HGVs 2.7% | 20,713 |
| A40(T) to A4020 Ealing · 2.0 mi · HGVs 3.9% | 16,631 |
| A404 to A4005 Harrow Rd Brent, Harrow · 0.6 mi · HGVs 2.9% | 14,558 |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
Route
Brent to Ealing · 6.0 miles
A4127 traffic and collisions by section
5 sections between junctions, in route order. Each is the average of its DfT count points, weighted by length.
Sections Tap a column heading to sort
| # | |||
|---|---|---|---|
| 1 | A404 to A4005 Harrow RdBrent, Harrow | 14,558 | 9 |
| 2 | A4005 to A4090Harrow, Ealing | 20,713 | 29 |
| 3 | A4090 to A40(T)Ealing | 22,600 | 55 |
| 4 | A40(T) to A4020Ealing | 16,631 | 98 |
| 5 | A4020 to A3005Ealing | 26,555 | 33 |
Vehicles a day is the average daily flow in 2025. “Since 2019” compares the same count points. Collisions are those with the A4127 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.
A4127 traffic by vehicle type
Cars and taxis make up 78.7% of the vehicle miles on the A4127. HGVs account for 3.8%, rising to 7.1% on A4090 to A40(T).
Vehicle mix, 2025
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
HGV share of traffic
| Year | HGV share |
|---|---|
| 2000 | 3.3% |
| 2001 | 2.8% |
| 2002 | 2.5% |
| 2003 | 2.5% |
| 2004 | 2.8% |
| 2005 | 2.9% |
| 2006 | 2.8% |
| 2007 | 4.0% |
| 2008 | 3.8% |
| 2009 | 3.6% |
| 2010 | 3.6% |
| 2011 | 4.9% |
| 2012 | 5.2% |
| 2013 | 5.3% |
| 2014 | 5.1% |
| 2015 | 5.0% |
| 2016 | 4.0% |
| 2017 | 3.4% |
| 2018 | 3.3% |
| 2019 | 3.3% |
| 2020 | 4.6% |
| 2021 | 4.6% |
| 2022 | 5.0% |
| 2023 | 4.9% |
| 2024 | 4.9% |
| 2025 | 3.8% |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
A4127 traffic trend
Traffic on the A4127 came to 45 million vehicle miles in 2025. At the count points present in both years, it is down 9.0% on 2019, before the pandemic, and down 9.9% on 2015.
Vehicle miles a year
Like for like, traffic is down 18.8% on 2000.
| Year | Vehicle miles |
|---|---|
| 2000 | 54m |
| 2001 | 55m |
| 2002 | 55m |
| 2003 | 54m |
| 2004 | 54m |
| 2005 | 54m |
| 2006 | 56m |
| 2007 | 50m |
| 2008 | 47m |
| 2009 | 45m |
| 2010 | 44m |
| 2011 | 46m |
| 2012 | 48m |
| 2013 | 48m |
| 2014 | 48m |
| 2015 | 48m |
| 2016 | 46m |
| 2017 | 49m |
| 2018 | 50m |
| 2019 | 50m |
| 2020 | 39m |
| 2021 | 45m |
| 2022 | 46m |
| 2023 | 46m |
| 2024 | 45m |
| 2025 | 45m |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
Average daily flow
| Year | Vehicles a day |
|---|---|
| 2000 | 25,375 |
| 2001 | 26,032 |
| 2002 | 25,851 |
| 2003 | 25,404 |
| 2004 | 25,563 |
| 2005 | 25,518 |
| 2006 | 26,222 |
| 2007 | 23,507 |
| 2008 | 22,380 |
| 2009 | 21,337 |
| 2010 | 20,819 |
| 2011 | 21,862 |
| 2012 | 22,644 |
| 2013 | 22,666 |
| 2014 | 22,738 |
| 2015 | 22,743 |
| 2016 | 21,866 |
| 2017 | 22,905 |
| 2018 | 22,617 |
| 2019 | 22,674 |
| 2020 | 17,670 |
| 2021 | 20,339 |
| 2022 | 20,780 |
| 2023 | 20,812 |
| 2024 | 20,627 |
| 2025 | 20,540 |
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. In 2025, 3 of the 7 count points were counted; DfT estimated the rest from earlier counts and local trends.
A4127 collisions
Police recorded 224 collisions with the A4127 as the first road from 2021 to 2025, 33 of them fatal or serious, including 4 fatal. That is 99.2 per 100 million vehicle miles, higher than the 31.5 for all A-roads in Great Britain. On average there were 7.5 a year for each mile of road.
Reported collisions by year
Down 37.9% from 2021 to 2025.
| Year | Slight | Fatal or serious |
|---|---|---|
| 2021 | 57 | 9 |
| 2022 | 41 | 7 |
| 2023 | 31 | 5 |
| 2024 | 28 | 5 |
| 2025 | 34 | 7 |
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.
| Section | Per 100m vehicle miles |
|---|---|
| A40(T) to A4020 Ealing · 98 collisions | 160.8 |
| A4005 to A4090 Harrow, Ealing · 29 collisions | 127.8 |
| A4090 to A40(T) Ealing · 55 collisions | 99.0 |
| A4020 to A3005 Ealing · 33 collisions | 46.8 |
Source:DfT STATS19,UK Motoring analysis 2021 to 2025 Updated
A further 55 collisions were recorded at junctions where the A4127 was the second road; they are not in the figures above. Fatal or serious uses DfT’s adjusted serious figures. 100.0% of the collisions could be placed on a section. How we count collisions
Council areas on the A4127
In route order. Each is the highway authority DfT files the count points under.
- Brent
- Harrow
- Ealing
Data sources and methodology
| 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 | 7 count points in 2025 | 15 September 2026 |
| Reported collisions | Road safety open data (STATS19) Department for Transport Derived statistics UK Motoring | 2021 to 2025 | 224 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.