A-road
A509 traffic and collisions
The A509 is an A-road of 32.5 miles, from Milton Keynes to North Northamptonshire. This page covers its traffic at 13 DfT count points since 2000 and the collisions police recorded on it.
- Traffic in 2025 217m vehicle miles
- Average daily traffic 18,268 vehicles a day, both directions
- Busiest section 32,495 A5193 to A45
- HGV share 4.6% of vehicle miles
- Traffic since 2019 −0.5% same count points
- Collisions, 2021 to 2025 194 18.5 per 100m vehicle miles
How busy is the A509?
On an average day in 2025, 18,268 vehicles passed each point on the A509, counting both directions. The busiest section is A5193 to A45 (North Northamptonshire), with 32,495 a day; the quietest listed is A428 to A5193, with 13,908.
Busiest sections, 2025
A5193 to A45 carries 1.8 times the road’s average flow.
| Section | Vehicles a day |
|---|---|
| A5193 to A45 North Northamptonshire · 0.5 mi · HGVs 2.3% | 32,495 |
| A45 to A4500/A5128 North Northamptonshire · 0.7 mi · HGVs 4.8% | 29,481 |
| B526 to A422 Milton Keynes · 2.1 mi · HGVs 3.9% | 26,921 |
| Roundbaout A510/A5193/A509 to Junction A14(T)/A509 North Northamptonshire · 4.2 mi · HGVs 5.7% | 22,560 |
| A4500/A5128 to Rutherford Drive North Northamptonshire · 1.0 mi · HGVs 6.7% | 21,278 |
| A14(T) to A6003 North Northamptonshire · 1.3 mi · HGVs 0.4% | 17,997 |
| A509 to M1 J14 Milton Keynes · 1.4 mi · HGVs 6.2% | 17,319 |
| Rutherford Drive to A510/A5193 North Northamptonshire · 2.2 mi · HGVs 7.8% | 16,583 |
| Roundabout A5/A509 to Roundabout A509/A4146 (Near M1 J14) Milton Keynes · 4.8 mi · HGVs 2.8% | 16,328 |
| A422 to A428 Milton Keynes · 6.2 mi · HGVs 4.3% | 15,676 |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
Route
Milton Keynes to North Northamptonshire · 32.5 miles
A509 traffic and collisions by section
12 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 | Roundabout A5/A509 to Roundabout A509/A4146 (Near M1 J14)Milton Keynes | 16,328 | 39 |
| 2 | M1 Junction 14 to A5130Milton Keynes | 43,699 | 4 |
| 3 | A509 to M1 J14Milton Keynes | 17,319 | 6 |
| 4 | B526 to A422Milton Keynes | 26,921 | 10 |
| 5 | A422 to A428Milton Keynes | 15,676 | 31 |
| 6 | A428 to A5193Milton Keynes, North Northamptonshire | 13,908 | 22 |
| 7 | A5193 to A45North Northamptonshire | 32,495 | 7 |
| 8 | A45 to A4500/A5128North Northamptonshire | 29,481 | 4 |
| 9 | A4500/A5128 to Rutherford DriveNorth Northamptonshire | 21,278 | 6 |
| 10 | Rutherford Drive to A510/A5193North Northamptonshire | 16,583 | 11 |
| 11 | Roundbaout A510/A5193/A509 to Junction A14(T)/A509North Northamptonshire | 22,560 | 34 |
| 12 | A14(T) to A6003North Northamptonshire | 17,997 | 15 |
Vehicles a day is the average daily flow in 2025. “Since 2019” compares the same count points. Collisions are those with the A509 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.
A509 traffic by vehicle type
Cars and taxis make up 79.3% of the vehicle miles on the A509. HGVs account for 4.6%, rising to 7.8% on Rutherford Drive to A510/A5193.
Vehicle mix, 2025
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
HGV share of traffic
| Year | HGV share |
|---|---|
| 2000 | 6.0% |
| 2001 | 4.8% |
| 2002 | 5.4% |
| 2003 | 5.6% |
| 2004 | 5.5% |
| 2005 | 5.3% |
| 2006 | 5.0% |
| 2007 | 5.0% |
| 2008 | 5.0% |
| 2009 | 4.5% |
| 2010 | 4.7% |
| 2011 | 4.6% |
| 2012 | 4.1% |
| 2013 | 4.2% |
| 2014 | 4.0% |
| 2015 | 4.0% |
| 2016 | 4.1% |
| 2017 | 4.3% |
| 2018 | 4.3% |
| 2019 | 4.4% |
| 2020 | 5.6% |
| 2021 | 6.0% |
| 2022 | 5.2% |
| 2023 | 4.7% |
| 2024 | 4.6% |
| 2025 | 4.6% |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
A509 traffic trend
Traffic on the A509 came to 217 million vehicle miles in 2025. At the count points present in both years, it is down 0.5% on 2019, before the pandemic, and down 0.9% on 2015.
Vehicle miles a year
Like for like, traffic is up 3.7% on 2000.
| Year | Vehicle miles |
|---|---|
| 2000 | 199m |
| 2001 | 199m |
| 2002 | 206m |
| 2003 | 208m |
| 2004 | 197m |
| 2005 | 194m |
| 2006 | 193m |
| 2007 | 200m |
| 2008 | 199m |
| 2009 | 200m |
| 2010 | 196m |
| 2011 | 198m |
| 2012 | 198m |
| 2013 | 196m |
| 2014 | 202m |
| 2015 | 208m |
| 2016 | 211m |
| 2017 | 220m |
| 2018 | 229m |
| 2019 | 230m |
| 2020 | 178m |
| 2021 | 196m |
| 2022 | 210m |
| 2023 | 214m |
| 2024 | 215m |
| 2025 | 217m |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
Average daily flow
| Year | Vehicles a day |
|---|---|
| 2000 | 18,161 |
| 2001 | 18,190 |
| 2002 | 18,777 |
| 2003 | 18,957 |
| 2004 | 17,949 |
| 2005 | 17,736 |
| 2006 | 17,633 |
| 2007 | 18,276 |
| 2008 | 18,195 |
| 2009 | 18,248 |
| 2010 | 17,926 |
| 2011 | 18,097 |
| 2012 | 18,033 |
| 2013 | 17,914 |
| 2014 | 18,464 |
| 2015 | 18,965 |
| 2016 | 19,282 |
| 2017 | 19,810 |
| 2018 | 19,898 |
| 2019 | 19,934 |
| 2020 | 15,442 |
| 2021 | 16,526 |
| 2022 | 17,725 |
| 2023 | 18,022 |
| 2024 | 18,118 |
| 2025 | 18,268 |
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 (65.5% of today’s road for 2019). In 2025, 2 of the 13 count points were counted; DfT estimated the rest from earlier counts and local trends.
A509 collisions
Police recorded 194 collisions with the A509 as the first road from 2021 to 2025, 47 of them fatal or serious. That is 18.5 per 100 million vehicle miles, lower than the 31.5 for all A-roads in Great Britain. On average there were 1.2 a year for each mile of road.
Reported collisions by year
Up 12.1% from 2021 to 2025.
| Year | Slight | Fatal or serious |
|---|---|---|
| 2021 | 24 | 9 |
| 2022 | 37 | 10 |
| 2023 | 29 | 10 |
| 2024 | 31 | 7 |
| 2025 | 27 | 10 |
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 |
|---|---|
| A14(T) to A6003 North Northamptonshire · 15 collisions | 38.4 |
| Roundbaout A510/A5193/A509 to Junction A14(T)/A509 North Northamptonshire · 34 collisions | 33.2 |
| Roundabout A5/A509 to Roundabout A509/A4146 (Near M1 J14) Milton Keynes · 39 collisions | 28.4 |
| A422 to A428 Milton Keynes · 31 collisions | 17.3 |
| Rutherford Drive to A510/A5193 North Northamptonshire · 11 collisions | 17.2 |
| A428 to A5193 Milton Keynes, North Northamptonshire · 22 collisions | 11.7 |
| B526 to A422 Milton Keynes · 10 collisions | 10.1 |
Source:DfT STATS19,UK Motoring analysis 2021 to 2025 Updated
A further 41 collisions were recorded at junctions where the A509 was the second road; they are not in the figures above. Fatal or serious uses DfT’s adjusted serious figures. 97.4% of the collisions could be placed on a section. How we count collisions
Council areas on the A509
In route order. Each is the highway authority DfT files the count points under.
- Milton Keynes
- North Northamptonshire
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 | 13 count points in 2025 | 15 September 2026 |
| Reported collisions | Road safety open data (STATS19) Department for Transport Derived statistics UK Motoring | 2021 to 2025 | 194 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.