Motorway
M23 traffic and collisions
The M23 is a motorway of 17.4 miles, from Surrey to West Sussex. This page covers its traffic at 8 DfT count points since 2000 and the collisions police recorded on it.
- Traffic in 2025 591m vehicle miles
- Average daily traffic 92,982 vehicles a day, both directions
- Busiest section 119,367 A25 Flyover (Bletchingley Road) with M23 to J9
- HGV share 4.9% of vehicle miles
- Traffic since 2019 −0.3% same count points
- Collisions, 2021 to 2025 150 5.4 per 100m vehicle miles
How busy is the M23?
On an average day in 2025, 92,982 vehicles passed each point on the M23, counting both directions. The busiest section is A25 Flyover (Bletchingley Road) with M23 to J9 (Surrey), with 119,367 a day; the quietest listed is J8 to J7, with 33,107.
Busiest sections, 2025
A25 Flyover (Bletchingley Road) with M23 to J9 carries 1.3 times the road’s average flow.
| Section | Vehicles a day |
|---|---|
| A25 Flyover (Bletchingley Road) with M23 to J9 Surrey · 6.0 mi · HGVs 4.9% | 119,367 |
| J7 to A25 Flyover (Bletchingley Road) with M23 Surrey · 1.6 mi · HGVs 4.9% | 114,480 |
| J10 to J9 West Sussex · 1.9 mi · HGVs 4.9% | 97,998 |
| J10A to J10 West Sussex · 1.9 mi · HGVs 5.1% | 90,546 |
| J11 to J10A West Sussex · 2.9 mi · HGVs 5.2% | 79,264 |
| J8 to J7 Surrey · 1.9 mi · HGVs 6.1% | 33,107 |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
Route
Surrey to West Sussex · 17.4 miles
M23 traffic and collisions by section
7 sections between junctions, in route order. Each is the average of its DfT count points, weighted by length. 1 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 | J8 to J7Surrey | 33,107 | 3 |
| 2 | J7 to A25 Flyover (Bletchingley Road) with M23Surrey | 114,480 | 13 |
| 3 | A25 Flyover (Bletchingley Road) with M23 to J9Surrey | 119,367 | 47 |
| 4 | J10 to J9West Sussex | 97,998 | 21 |
| 5 | J10A to J10West Sussex | 90,546 | 30 |
| 6 | J11 to J10AWest Sussex | 79,264 | 22 |
| 7 | A23(T) to A264West Sussex | 57,104 | 5 |
Vehicles a day is the average daily flow in 2025. “Since 2019” compares the same count points. Collisions are those with the M23 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.
M23 traffic by vehicle type
Cars and taxis make up 77.8% of the vehicle miles on the M23. HGVs account for 4.9%, rising to 6.1% on J8 to J7.
Vehicle mix, 2025
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
HGV share of traffic
| Year | HGV share |
|---|---|
| 2000 | 5.5% |
| 2001 | 5.5% |
| 2002 | 5.3% |
| 2003 | 5.2% |
| 2004 | 5.1% |
| 2005 | 4.9% |
| 2006 | 5.1% |
| 2007 | 5.2% |
| 2008 | 5.7% |
| 2009 | 4.8% |
| 2010 | 5.5% |
| 2011 | 5.3% |
| 2012 | 5.2% |
| 2013 | 5.2% |
| 2014 | 5.4% |
| 2015 | 4.9% |
| 2016 | 5.0% |
| 2017 | 4.9% |
| 2018 | 5.0% |
| 2019 | 5.7% |
| 2020 | 7.3% |
| 2021 | 6.8% |
| 2022 | 5.2% |
| 2023 | 5.0% |
| 2024 | 4.8% |
| 2025 | 4.9% |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
M23 traffic trend
Traffic on the M23 came to 591 million vehicle miles in 2025. At the count points present in both years, it is about the same as in 2019, before the pandemic, and up 3.0% on 2015.
Vehicle miles a year
Like for like, traffic is down 4.0% on 2000.
| Year | Vehicle miles |
|---|---|
| 2000 | 559m |
| 2001 | 573m |
| 2002 | 569m |
| 2003 | 598m |
| 2004 | 629m |
| 2005 | 654m |
| 2006 | 603m |
| 2007 | 601m |
| 2008 | 582m |
| 2009 | 587m |
| 2010 | 562m |
| 2011 | 568m |
| 2012 | 575m |
| 2013 | 562m |
| 2014 | 579m |
| 2015 | 612m |
| 2016 | 598m |
| 2017 | 615m |
| 2018 | 616m |
| 2019 | 570m |
| 2020 | 359m |
| 2021 | 440m |
| 2022 | 563m |
| 2023 | 586m |
| 2024 | 589m |
| 2025 | 591m |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
Average daily flow
| Year | Vehicles a day |
|---|---|
| 2000 | 88,573 |
| 2001 | 90,800 |
| 2002 | 90,156 |
| 2003 | 94,737 |
| 2004 | 99,575 |
| 2005 | 103,589 |
| 2006 | 95,478 |
| 2007 | 95,111 |
| 2008 | 92,104 |
| 2009 | 92,912 |
| 2010 | 88,992 |
| 2011 | 89,963 |
| 2012 | 91,010 |
| 2013 | 89,037 |
| 2014 | 91,695 |
| 2015 | 96,849 |
| 2016 | 94,749 |
| 2017 | 97,414 |
| 2018 | 96,961 |
| 2019 | 89,696 |
| 2020 | 56,497 |
| 2021 | 69,203 |
| 2022 | 88,639 |
| 2023 | 92,196 |
| 2024 | 92,705 |
| 2025 | 92,982 |
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 (56.3% of today’s road for 2019). In 2025, 4 of the 8 count points were counted; DfT estimated the rest from earlier counts and local trends.
M23 collisions
Police recorded 150 collisions with the M23 as the first road from 2021 to 2025, 42 of them fatal or serious, including 3 fatal. That is 5.4 per 100 million vehicle miles, higher than the 4.9 for all motorways in Great Britain. On average there were 1.7 a year for each mile of road.
Reported collisions by year
Down 48.5% from 2021 to 2025.
| Year | Slight | Fatal or serious |
|---|---|---|
| 2021 | 29 | 4 |
| 2022 | 18 | 11 |
| 2023 | 18 | 8 |
| 2024 | 31 | 14 |
| 2025 | 12 | 5 |
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 |
|---|---|
| J10A to J10 West Sussex · 30 collisions | 9.8 |
| J7 to A25 Flyover (Bletchingley Road) with M23 Surrey · 13 collisions | 9.5 |
| A25 Flyover (Bletchingley Road) with M23 to J9 Surrey · 47 collisions | 9.0 |
| J10 to J9 West Sussex · 21 collisions | 6.5 |
| J11 to J10A West Sussex · 22 collisions | 5.5 |
Source:DfT STATS19,UK Motoring analysis 2021 to 2025 Updated
A further 17 collisions were recorded at junctions where the M23 was the second road; they are not in the figures above. Fatal or serious uses DfT’s adjusted serious figures. 94.0% of the collisions could be placed on a section. How we count collisions
Council areas on the M23
In route order. Each is the highway authority DfT files the count points under.
- Surrey
- West Sussex
Planned closures on the M23 in England
National Highways has 18 planned closures on the M23 between 16 September 2026 and 30 September 2026, 15 of them starting in that period. 10 close a carriageway rather than a lane or slip road, and 15 start between 7pm and 6am.
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Lane or slip M23 northbound lane 1 closure ( 52/6 to 50/0)
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Carriageway M23 northbound Jct 10 exit slip road closure
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Lane or slip M23 northbound lane 1 closure ( 52/6 to 50/0)
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Carriageway M23 southbound Jct 10a exit slip road closure
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Carriageway M23 southbound Jct 10a exit slip road closure
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Lane or slip M23 northbound lane 1 closure ( 52/6 to 50/0)
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Carriageway M23 southbound Jct 10a exit slip road closure
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Carriageway M23 Southbound Jct 7 to Jct 8 lane closure
10 more planned closures in this period are not shown.
Planned closures only: National Highways can cancel or change them, and closures caused by incidents are not shown. Council roads in England are not covered. Roadworks and closures across the UK
Source:National Highways 2026-09-16 to 2026-09-30 Updated
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 | 8 count points in 2025 | 15 September 2026 |
| Reported collisions | Road safety open data (STATS19) Department for Transport Derived statistics UK Motoring | 2021 to 2025 | 150 reported collisions | 15 September 2026 |
| Planned closures | Transport Data Feeds (DATEX II) National Highways | 2026-09-16 to 2026-09-30 | 2,304 planned closure schemes | 16 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.
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