A-road
A5109 traffic and collisions
The A5109 is an A-road of 5.4 miles, in Barnet. This page covers its traffic at 5 DfT count points since 2000 and the collisions police recorded on it.
- Traffic in 2025 32m vehicle miles
- Average daily traffic 16,054 vehicles a day, both directions
- Busiest section 19,655 A5100 to A5
- HGV share 0.9% of vehicle miles
- Traffic since 2019 −2.2% same count points
- Collisions, 2021 to 2025 95 65.0 per 100m vehicle miles
How busy is the A5109?
On an average day in 2025, 16,054 vehicles passed each point on the A5109, counting both directions. The busiest section is A5100 to A5 (Barnet), with 19,655 a day; the quietest listed is Highwood Hill to A1, with 13,662.
Busiest sections, 2025
A5100 to A5 carries 1.2 times the road’s average flow.
| Section | Vehicles a day |
|---|---|
| A5100 to A5 Barnet · 1.1 mi · HGVs 0.3% | 19,655 |
| A1000/A109 to Barnet Lane Barnet · 1.2 mi · HGVs 0.4% | 16,179 |
| Barnet Lane to Highwood Hill Barnet · 2.0 mi · HGVs 1.0% | 15,143 |
| Highwood Hill to A1 Barnet · 0.7 mi · HGVs 2.1% | 13,662 |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
Route
In Barnet · 5.4 miles
A5109 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 | A1000/A109 to Barnet LaneBarnet | 16,179 | 37 |
| 2 | Barnet Lane to Highwood HillBarnet | 15,143 | 10 |
| 3 | Highwood Hill to A1Barnet | 13,662 | 5 |
| 4 | A1/A41 to A5100Barnet | 14,511 | 16 |
| 5 | A5100 to A5Barnet | 19,655 | 26 |
Vehicles a day is the average daily flow in 2025. “Since 2019” compares the same count points. Collisions are those with the A5109 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.
A5109 traffic by vehicle type
Cars and taxis make up 83.2% of the vehicle miles on the A5109. HGVs account for 0.9%, rising to 2.1% on Highwood Hill to A1.
Vehicle mix, 2025
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
HGV share of traffic
| Year | HGV share |
|---|---|
| 2000 | 1.5% |
| 2001 | 1.3% |
| 2002 | 1.2% |
| 2003 | 1.0% |
| 2004 | 1.3% |
| 2005 | 1.2% |
| 2006 | 1.2% |
| 2007 | 1.4% |
| 2008 | 1.6% |
| 2009 | 1.6% |
| 2010 | 1.5% |
| 2011 | 1.5% |
| 2012 | 1.6% |
| 2013 | 1.5% |
| 2014 | 1.4% |
| 2015 | 1.6% |
| 2016 | 1.7% |
| 2017 | 1.3% |
| 2018 | 1.3% |
| 2019 | 0.9% |
| 2020 | 1.1% |
| 2021 | 1.1% |
| 2022 | 1.1% |
| 2023 | 1.1% |
| 2024 | 1.1% |
| 2025 | 0.9% |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
A5109 traffic trend
Traffic on the A5109 came to 31.6 million vehicle miles in 2025. At the count points present in both years, it is down 2.2% on 2019, before the pandemic, and down 8.4% on 2015.
Vehicle miles a year
Like for like, traffic is down 8.0% on 2000.
| Year | Vehicle miles |
|---|---|
| 2000 | 34m |
| 2001 | 34m |
| 2002 | 36m |
| 2003 | 37m |
| 2004 | 38m |
| 2005 | 38m |
| 2006 | 39m |
| 2007 | 38m |
| 2008 | 37m |
| 2009 | 36m |
| 2010 | 38m |
| 2011 | 37m |
| 2012 | 36m |
| 2013 | 37m |
| 2014 | 37m |
| 2015 | 35m |
| 2016 | 35m |
| 2017 | 34m |
| 2018 | 34m |
| 2019 | 32m |
| 2020 | 25m |
| 2021 | 27m |
| 2022 | 29m |
| 2023 | 29m |
| 2024 | 29m |
| 2025 | 32m |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
Average daily flow
| Year | Vehicles a day |
|---|---|
| 2000 | 17,450 |
| 2001 | 17,215 |
| 2002 | 18,254 |
| 2003 | 18,840 |
| 2004 | 19,422 |
| 2005 | 19,306 |
| 2006 | 19,534 |
| 2007 | 19,310 |
| 2008 | 18,626 |
| 2009 | 18,450 |
| 2010 | 19,051 |
| 2011 | 18,948 |
| 2012 | 18,389 |
| 2013 | 18,549 |
| 2014 | 18,809 |
| 2015 | 17,533 |
| 2016 | 17,523 |
| 2017 | 17,235 |
| 2018 | 17,253 |
| 2019 | 16,415 |
| 2020 | 12,547 |
| 2021 | 13,830 |
| 2022 | 14,539 |
| 2023 | 14,844 |
| 2024 | 14,877 |
| 2025 | 16,054 |
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 5 count points were counted; DfT estimated the rest from earlier counts and local trends.
A5109 collisions
Police recorded 95 collisions with the A5109 as the first road from 2021 to 2025, fewer than 3 of them fatal or serious. That is 65.0 per 100 million vehicle miles, higher than the 31.5 for all A-roads in Great Britain. On average there were 3.5 a year for each mile of road.
Reported collisions by year
Down 16.7% from 2021 to 2025.
| Year | Collisions |
|---|---|
| 2021 | 18 |
| 2022 | 23 |
| 2023 | 18 |
| 2024 | 21 |
| 2025 | 15 |
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 |
|---|---|
| A1000/A109 to Barnet Lane Barnet · 37 collisions | 111.6 |
| A5100 to A5 Barnet · 26 collisions | 80.0 |
| Barnet Lane to Highwood Hill Barnet · 10 collisions | 19.1 |
Source:DfT STATS19,UK Motoring analysis 2021 to 2025 Updated
A further 37 collisions were recorded at junctions where the A5109 was the second road; they are not in the figures above. Fatal or serious uses DfT’s adjusted serious figures. 98.9% of the collisions could be placed on a section. How we count collisions
Council areas on the A5109
In route order. Each is the highway authority DfT files the count points under.
- Barnet
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 | 5 count points in 2025 | 15 September 2026 |
| Reported collisions | Road safety open data (STATS19) Department for Transport Derived statistics UK Motoring | 2021 to 2025 | 95 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.