A-road
A4086 traffic and collisions
The A4086 is an A-road of 18.3 miles, from Conwy to Gwynedd. This page covers its traffic at 7 DfT count points since 2000 and the collisions police recorded on it.
- Traffic in 2025 22m vehicle miles
- Average daily traffic 3,244 vehicles a day, both directions
- Busiest section 6,500 Caer Glyddyn to Penilyn / Pool Side
- HGV share 1.7% of vehicle miles
- Traffic since 2019 −14.1% same count points
How busy is the A4086?
On an average day in 2025, 3,244 vehicles passed each point on the A4086, counting both directions. The busiest section is Caer Glyddyn to Penilyn / Pool Side (Gwynedd), with 6,500 a day; the quietest listed is A498 to C-road just north of Dolbadarn Castle, with 1,891.
Busiest sections, 2025
Caer Glyddyn to Penilyn / Pool Side carries 2.0 times the road’s average flow.
| Section | Vehicles a day |
|---|---|
| Caer Glyddyn to Penilyn / Pool Side Gwynedd · 1.5 mi · HGVs 1.6% | 6,500 |
| Llwyn Coed (near Penllyn Rail Station) to Caer Glyddyn Gwynedd · 3.9 mi · HGVs 1.5% | 5,704 |
| C-road just north of Dolbadarn Castle to B4547 Gwynedd · 2.4 mi · HGVs 2.1% | 2,692 |
| A5 to A498 Conwy, Gwynedd · 4.2 mi · HGVs 1.3% | 2,062 |
| A498 to C-road just north of Dolbadarn Castle Gwynedd · 6.2 mi · HGVs 2.1% | 1,891 |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
Route
Conwy to Gwynedd · 18.3 miles
A4086 traffic and collisions by section
6 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 | A5 to A498Conwy, Gwynedd | 2,062 | – |
| 2 | A498 to C-road just north of Dolbadarn CastleGwynedd | 1,891 | – |
| 3 | C-road just north of Dolbadarn Castle to B4547Gwynedd | 2,692 | – |
| 4 | Llwyn Coed (near Penllyn Rail Station) to Caer GlyddynGwynedd | 5,704 | – |
| 5 | Caer Glyddyn to Penilyn / Pool SideGwynedd | 6,500 | – |
| 6 | B4419 Bont Bridd (Bridge St) to A487 roundaboutGwynedd | 5,256 | – |
Vehicles a day is the average daily flow in 2025. “Since 2019” compares the same count points. Collisions are those with the A4086 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.
A4086 traffic by vehicle type
Cars and taxis make up 75.6% of the vehicle miles on the A4086. HGVs account for 1.7%.
Vehicle mix, 2025
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
HGV share of traffic
| Year | HGV share |
|---|---|
| 2000 | 2.0% |
| 2001 | 2.5% |
| 2002 | 2.1% |
| 2003 | 1.9% |
| 2004 | 2.1% |
| 2005 | 2.3% |
| 2006 | 2.3% |
| 2007 | 2.1% |
| 2008 | 2.1% |
| 2009 | 2.0% |
| 2010 | 2.0% |
| 2011 | 1.8% |
| 2012 | 1.6% |
| 2013 | 1.6% |
| 2014 | 1.6% |
| 2015 | 1.5% |
| 2016 | 1.9% |
| 2017 | 1.9% |
| 2018 | 1.9% |
| 2019 | 2.0% |
| 2020 | 2.4% |
| 2021 | 2.3% |
| 2022 | 2.2% |
| 2023 | 1.7% |
| 2024 | 1.7% |
| 2025 | 1.7% |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
A4086 traffic trend
Traffic on the A4086 came to 21.7 million vehicle miles in 2025. At the count points present in both years, it is down 14.1% on 2019, before the pandemic, and down 11.2% on 2015.
Vehicle miles a year
Like for like, traffic is up 1.4% on 2000.
| Year | Vehicle miles |
|---|---|
| 2000 | 19m |
| 2001 | 19m |
| 2002 | 20m |
| 2003 | 21m |
| 2004 | 20m |
| 2005 | 21m |
| 2006 | 21m |
| 2007 | 21m |
| 2008 | 21m |
| 2009 | 22m |
| 2010 | 21m |
| 2011 | 21m |
| 2012 | 22m |
| 2013 | 22m |
| 2014 | 22m |
| 2015 | 24m |
| 2016 | 22m |
| 2017 | 22m |
| 2018 | 22m |
| 2019 | 22m |
| 2020 | 16m |
| 2021 | 18m |
| 2022 | 21m |
| 2023 | 21m |
| 2024 | 21m |
| 2025 | 22m |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
Average daily flow
| Year | Vehicles a day |
|---|---|
| 2000 | 2,999 |
| 2001 | 2,996 |
| 2002 | 3,063 |
| 2003 | 3,215 |
| 2004 | 3,093 |
| 2005 | 3,234 |
| 2006 | 3,222 |
| 2007 | 3,312 |
| 2008 | 3,279 |
| 2009 | 3,342 |
| 2010 | 3,286 |
| 2011 | 3,333 |
| 2012 | 3,368 |
| 2013 | 3,406 |
| 2014 | 3,481 |
| 2015 | 3,753 |
| 2016 | 3,446 |
| 2017 | 3,468 |
| 2018 | 3,479 |
| 2019 | 3,485 |
| 2020 | 2,504 |
| 2021 | 2,764 |
| 2022 | 3,088 |
| 2023 | 3,164 |
| 2024 | 3,203 |
| 2025 | 3,244 |
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 (70.5% of today’s road for 2019). In 2025, 0 of the 7 count points were counted; DfT estimated the rest from earlier counts and local trends.
A4086 collisions
Police recorded fewer than 3 collisions with the A4086 as the first road from 2021 to 2025, 10 of them fatal or serious.
Reported collisions by year
Up 66.7% from 2021 to 2025.
| Year | Collisions | Fatal or serious |
|---|---|---|
| 2021 | 3 | fewer than 3 |
| 2022 | 3 | 0 |
| 2023 | 6 | 4 |
| 2024 | fewer than 3 | fewer than 3 |
| 2025 | 5 | fewer than 3 |
Source:DfT STATS19,UK Motoring analysis 2021 to 2025 Updated
Fatal or serious uses DfT’s adjusted serious figures. How we count collisions
Council areas on the A4086
In route order. Each is the highway authority DfT files the count points under.
- Conwy
- Gwynedd
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 | 19 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.