A-road
A416 traffic and collisions
The A416 is an A-road of 8.2 miles, from Buckinghamshire to Hertfordshire. This page covers its traffic at 10 DfT count points since 2000 and the collisions police recorded on it.
- Traffic in 2025 43m vehicle miles
- Average daily traffic 14,345 vehicles a day, both directions
- Busiest section 28,253 B485 to B4505
- HGV share 2.2% of vehicle miles
- Traffic since 2019 −0.8% same count points
- Collisions, 2021 to 2025 61 30.5 per 100m vehicle miles
How busy is the A416?
On an average day in 2025, 14,345 vehicles passed each point on the A416, counting both directions. The busiest section is B485 to B4505 (Buckinghamshire), with 28,253 a day; the quietest listed is A416 split Kingshll Way Rndbt to A4251, with 6,281.
Busiest sections, 2025
B485 to B4505 carries 2.0 times the road’s average flow.
| Section | Vehicles a day |
|---|---|
| B485 to B4505 Buckinghamshire · 0.6 mi · HGVs 1.4% | 28,253 |
| A404 to B485 Buckinghamshire · 1.8 mi · HGVs 1.5% | 16,163 |
| A355 to A404 Buckinghamshire · 1.2 mi · HGVs 2.5% | 15,594 |
| B4505 to Preston Hill Buckinghamshire · 0.6 mi · HGVs 3.1% | 14,291 |
| Preston Hill, Chesham to A416 split Buckinghamshire, Hertfordshire · 2.5 mi · HGVs 3.0% | 12,874 |
| A416 split Kingshll Way Rndbt to A4251 Hertfordshire · 1.1 mi · HGVs 1.5% | 6,281 |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
Route
Buckinghamshire to Hertfordshire · 8.2 miles
A416 traffic and collisions by section
7 sections between junctions, in route order. Each is the average of its DfT count points, weighted by length. 2 short link roads and spurs (0.2 miles) count in the road’s totals but are not listed.
Sections Tap a column heading to sort
| # | |||
|---|---|---|---|
| 1 | A355 to A404Buckinghamshire | 15,594 | 5 |
| 2 | A404 to B485Buckinghamshire | 16,163 | 24 |
| 3 | B485 to B4505Buckinghamshire | 28,253 | 14 |
| 4 | B4505 to Preston HillBuckinghamshire | 14,291 | 5 |
| 5 | Preston Hill, Chesham to A416 splitBuckinghamshire, Hertfordshire | 12,874 | 9 |
| 6 | A416 Chesham Road to A416 Kingshill WayHertfordshire | 15,945 | fewer than 3 |
| 7 | A416 split Kingshll Way Rndbt to A4251Hertfordshire | 6,281 | 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 A416 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.
A416 traffic by vehicle type
Cars and taxis make up 83.4% of the vehicle miles on the A416. HGVs account for 2.2%.
Vehicle mix, 2025
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
HGV share of traffic
| Year | HGV share |
|---|---|
| 2000 | 2.7% |
| 2001 | 2.8% |
| 2002 | 3.2% |
| 2003 | 3.3% |
| 2004 | 3.4% |
| 2005 | 3.5% |
| 2006 | 2.9% |
| 2007 | 3.0% |
| 2008 | 2.7% |
| 2009 | 2.4% |
| 2010 | 2.5% |
| 2011 | 2.5% |
| 2012 | 2.5% |
| 2013 | 2.6% |
| 2014 | 2.3% |
| 2015 | 2.3% |
| 2016 | 2.3% |
| 2017 | 2.1% |
| 2018 | 2.1% |
| 2019 | 2.1% |
| 2020 | 2.6% |
| 2021 | 2.7% |
| 2022 | 2.6% |
| 2023 | 2.5% |
| 2024 | 2.5% |
| 2025 | 2.2% |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
A416 traffic trend
Traffic on the A416 came to 42.9 million vehicle miles in 2025. At the count points present in both years, it is down 0.8% on 2019, before the pandemic, and down 1.6% on 2015.
Vehicle miles a year
Like for like, traffic is down 5.3% on 2000.
| Year | Vehicle miles |
|---|---|
| 2000 | 45m |
| 2001 | 46m |
| 2002 | 48m |
| 2003 | 46m |
| 2004 | 47m |
| 2005 | 46m |
| 2006 | 46m |
| 2007 | 46m |
| 2008 | 45m |
| 2009 | 45m |
| 2010 | 45m |
| 2011 | 45m |
| 2012 | 43m |
| 2013 | 42m |
| 2014 | 43m |
| 2015 | 44m |
| 2016 | 45m |
| 2017 | 42m |
| 2018 | 43m |
| 2019 | 43m |
| 2020 | 33m |
| 2021 | 36m |
| 2022 | 40m |
| 2023 | 41m |
| 2024 | 41m |
| 2025 | 43m |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
Average daily flow
| Year | Vehicles a day |
|---|---|
| 2000 | 15,146 |
| 2001 | 15,471 |
| 2002 | 15,901 |
| 2003 | 15,299 |
| 2004 | 15,705 |
| 2005 | 15,216 |
| 2006 | 15,371 |
| 2007 | 15,476 |
| 2008 | 14,970 |
| 2009 | 15,014 |
| 2010 | 14,892 |
| 2011 | 15,020 |
| 2012 | 14,198 |
| 2013 | 14,003 |
| 2014 | 14,410 |
| 2015 | 14,579 |
| 2016 | 14,931 |
| 2017 | 14,011 |
| 2018 | 14,369 |
| 2019 | 14,460 |
| 2020 | 10,952 |
| 2021 | 12,043 |
| 2022 | 13,276 |
| 2023 | 13,534 |
| 2024 | 13,726 |
| 2025 | 14,345 |
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, 4 of the 10 count points were counted; DfT estimated the rest from earlier counts and local trends.
A416 collisions
Police recorded 61 collisions with the A416 as the first road from 2021 to 2025, 10 of them fatal or serious. That is 30.5 per 100 million vehicle miles, close to the 31.5 for all A-roads in Great Britain. On average there were 1.5 a year for each mile of road.
Reported collisions by year
Down 31.3% from 2021 to 2025.
| Year | Collisions |
|---|---|
| 2021 | 16 |
| 2022 | 12 |
| 2023 | 13 |
| 2024 | 9 |
| 2025 | 11 |
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 |
|---|---|
| A404 to B485 Buckinghamshire · 24 collisions | 52.8 |
| B485 to B4505 Buckinghamshire · 14 collisions | 46.5 |
Source:DfT STATS19,UK Motoring analysis 2021 to 2025 Updated
A further 3 collisions were recorded at junctions where the A416 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 A416
In route order. Each is the highway authority DfT files the count points under.
- Buckinghamshire
- Hertfordshire
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 | 10 count points in 2025 | 15 September 2026 |
| Reported collisions | Road safety open data (STATS19) Department for Transport Derived statistics UK Motoring | 2021 to 2025 | 61 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.