A-road
A437 traffic and collisions
The A437 is an A-road of 7.3 miles, in Hillingdon. This page covers its traffic at 7 DfT count points since 2000 and the collisions police recorded on it.
- Traffic in 2025 46m vehicle miles
- Average daily traffic 17,166 vehicles a day, both directions
- Busiest section 22,123 A4020 to A40
- HGV share 1.5% of vehicle miles
- Traffic since 2019 +7.0% same count points
- Collisions, 2021 to 2025 186 82.0 per 100m vehicle miles
How busy is the A437?
On an average day in 2025, 17,166 vehicles passed each point on the A437, counting both directions. The busiest section is A4020 to A40 (Hillingdon), with 22,123 a day; the quietest listed is A4(T) to A312, with 14,673.
Busiest sections, 2025
A4020 to A40 carries 1.3 times the road’s average flow.
| Section | Vehicles a day |
|---|---|
| A4020 to A40 Hillingdon · 1.4 mi · HGVs 1.6% | 22,123 |
| A312 to A4020 Hillingdon · 2.9 mi · HGVs 1.8% | 17,355 |
| A4(T) to A312 Hillingdon · 1.6 mi · HGVs 0.5% | 14,673 |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
Route
In Hillingdon · 7.3 miles
A437 traffic and collisions by section
4 sections between junctions, in route order. Each is the average of its DfT count points, weighted by length. 3 short link roads and spurs (1.0 miles) count in the road’s totals but are not listed.
Sections Tap a column heading to sort
| # | |||
|---|---|---|---|
| 1 | A4(T) to A312Hillingdon | 14,673 | 61 |
| 2 | A312 to A4020Hillingdon | 17,355 | 75 |
| 3 | A4020 to A40Hillingdon | 22,123 | 48 |
| 4 | A40 to A437 Long LaneHillingdon | 8,666 | fewer than 3 |
Vehicles a day is the average daily flow in 2025. “Since 2019” compares the same count points. Collisions are those with the A437 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.
A437 traffic by vehicle type
Cars and taxis make up 80.6% of the vehicle miles on the A437. HGVs account for 1.5%.
Vehicle mix, 2025
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
HGV share of traffic
| Year | HGV share |
|---|---|
| 2000 | 2.3% |
| 2001 | 2.3% |
| 2002 | 2.5% |
| 2003 | 2.9% |
| 2004 | 3.1% |
| 2005 | 3.4% |
| 2006 | 2.8% |
| 2007 | 3.3% |
| 2008 | 2.9% |
| 2009 | 2.8% |
| 2010 | 3.0% |
| 2011 | 3.1% |
| 2012 | 3.3% |
| 2013 | 2.4% |
| 2014 | 2.1% |
| 2015 | 2.1% |
| 2016 | 1.9% |
| 2017 | 1.8% |
| 2018 | 1.5% |
| 2019 | 1.5% |
| 2020 | 1.8% |
| 2021 | 1.8% |
| 2022 | 1.8% |
| 2023 | 1.8% |
| 2024 | 1.5% |
| 2025 | 1.5% |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
A437 traffic trend
Traffic on the A437 came to 45.7 million vehicle miles in 2025. At the count points present in both years, it is up 7.0% on 2019, before the pandemic, and up 5.6% on 2015.
Vehicle miles a year
Like for like, traffic is down 18.5% on 2000.
| Year | Vehicle miles |
|---|---|
| 2000 | 55m |
| 2001 | 53m |
| 2002 | 51m |
| 2003 | 50m |
| 2004 | 50m |
| 2005 | 51m |
| 2006 | 52m |
| 2007 | 46m |
| 2008 | 51m |
| 2009 | 51m |
| 2010 | 45m |
| 2011 | 45m |
| 2012 | 40m |
| 2013 | 43m |
| 2014 | 44m |
| 2015 | 44m |
| 2016 | 46m |
| 2017 | 46m |
| 2018 | 43m |
| 2019 | 43m |
| 2020 | 40m |
| 2021 | 43m |
| 2022 | 45m |
| 2023 | 47m |
| 2024 | 46m |
| 2025 | 46m |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
Average daily flow
| Year | Vehicles a day |
|---|---|
| 2000 | 20,408 |
| 2001 | 19,422 |
| 2002 | 18,696 |
| 2003 | 18,488 |
| 2004 | 18,391 |
| 2005 | 18,962 |
| 2006 | 19,069 |
| 2007 | 17,096 |
| 2008 | 18,909 |
| 2009 | 18,718 |
| 2010 | 16,826 |
| 2011 | 16,799 |
| 2012 | 14,953 |
| 2013 | 15,720 |
| 2014 | 16,260 |
| 2015 | 16,261 |
| 2016 | 16,926 |
| 2017 | 16,852 |
| 2018 | 15,976 |
| 2019 | 16,014 |
| 2020 | 14,625 |
| 2021 | 15,885 |
| 2022 | 16,824 |
| 2023 | 16,978 |
| 2024 | 16,861 |
| 2025 | 17,166 |
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, 2 of the 7 count points were counted; DfT estimated the rest from earlier counts and local trends.
A437 collisions
Police recorded 186 collisions with the A437 as the first road from 2021 to 2025, fewer than 3 of them fatal or serious. That is 82.0 per 100 million vehicle miles, higher than the 31.5 for all A-roads in Great Britain. On average there were 5.1 a year for each mile of road.
Reported collisions by year
Up 87.5% from 2021 to 2025.
| Year | Collisions |
|---|---|
| 2021 | 24 |
| 2022 | 46 |
| 2023 | 33 |
| 2024 | 38 |
| 2025 | 45 |
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 |
|---|---|
| A4(T) to A312 Hillingdon · 61 collisions | 136.3 |
| A4020 to A40 Hillingdon · 48 collisions | 85.0 |
| A312 to A4020 Hillingdon · 75 collisions | 84.8 |
Source:DfT STATS19,UK Motoring analysis 2021 to 2025 Updated
A further 30 collisions were recorded at junctions where the A437 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 A437
In route order. Each is the highway authority DfT files the count points under.
- Hillingdon
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 | 186 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.