Motorway
M48 traffic and collisions
The M48 is a motorway of 13.0 miles in England and Wales, from South Gloucestershire to Monmouthshire. This page covers its traffic at 5 DfT count points since 2000 and the collisions police recorded on it.
- Traffic in 2025 97m vehicle miles
- Average daily traffic 20,430 vehicles a day, both directions
- Busiest section 29,540 J1 to J2
- HGV share 11.7% of vehicle miles
- Traffic since 2019 +7.6% same count points
- Collisions, 2021 to 2025 28 6.3 per 100m vehicle miles
How busy is the M48?
On an average day in 2025, 20,430 vehicles passed each point on the M48, counting both directions. The busiest section is J1 to J2 (South Gloucestershire, Gloucestershire, Monmouthshire), with 29,540 a day; the quietest listed is J2 to M4 (23), with 14,820.
Busiest sections, 2025
J1 to J2 carries 1.4 times the road’s average flow.
| Section | Vehicles a day |
|---|---|
| J1 to J2 South Gloucestershire, Gloucestershire, Monmouthshire · 3.1 mi · HGVs 7.4% | 29,540 |
| M4 (21) to J1 South Gloucestershire · 2.9 mi · HGVs 17.4% | 24,235 |
| J2 to M4 (23) Monmouthshire · 7.0 mi · HGVs 11.5% | 14,820 |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
Route
South Gloucestershire to Monmouthshire · 13.0 miles
M48 traffic and collisions by section
3 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 | M4 (21) to J1South Gloucestershire | 24,235 | 5 |
| 2 | J1 to J2South Gloucestershire, Gloucestershire, Monmouthshire | 29,540 | 9 |
| 3 | J2 to M4 (23)Monmouthshire | 14,820 | 14 |
Vehicles a day is the average daily flow in 2025. “Since 2019” compares the same count points. Collisions are those with the M48 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.
M48 traffic by vehicle type
Cars and taxis make up 71.5% of the vehicle miles on the M48. HGVs account for 11.7%, rising to 17.4% on M4 (21) to J1.
Vehicle mix, 2025
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
HGV share of traffic
| Year | HGV share |
|---|---|
| 2000 | 12.5% |
| 2001 | 12.0% |
| 2002 | 13.2% |
| 2003 | 12.6% |
| 2004 | 13.1% |
| 2005 | 12.8% |
| 2006 | 12.7% |
| 2007 | 12.5% |
| 2008 | 11.7% |
| 2009 | 10.9% |
| 2010 | 11.0% |
| 2011 | 10.6% |
| 2012 | 10.5% |
| 2013 | 10.9% |
| 2014 | 10.5% |
| 2015 | 10.5% |
| 2016 | 9.8% |
| 2017 | 10.1% |
| 2018 | 10.8% |
| 2019 | 10.7% |
| 2020 | 14.1% |
| 2021 | 13.7% |
| 2022 | 12.5% |
| 2023 | 11.5% |
| 2024 | 11.6% |
| 2025 | 11.7% |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
M48 traffic trend
Traffic on the M48 came to 96.9 million vehicle miles in 2025. At the count points present in both years, it is up 7.6% on 2019, before the pandemic, and up 21.8% on 2015.
Vehicle miles a year
Like for like, traffic is up 46.8% on 2000.
| Year | Vehicle miles |
|---|---|
| 2000 | 63m |
| 2001 | 65m |
| 2002 | 66m |
| 2003 | 68m |
| 2004 | 73m |
| 2005 | 76m |
| 2006 | 77m |
| 2007 | 79m |
| 2008 | 77m |
| 2009 | 76m |
| 2010 | 74m |
| 2011 | 74m |
| 2012 | 73m |
| 2013 | 73m |
| 2014 | 75m |
| 2015 | 76m |
| 2016 | 79m |
| 2017 | 80m |
| 2018 | 84m |
| 2019 | 90m |
| 2020 | 64m |
| 2021 | 73m |
| 2022 | 84m |
| 2023 | 95m |
| 2024 | 95m |
| 2025 | 97m |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
Average daily flow
| Year | Vehicles a day |
|---|---|
| 2000 | 13,607 |
| 2001 | 14,046 |
| 2002 | 14,178 |
| 2003 | 14,592 |
| 2004 | 15,781 |
| 2005 | 16,432 |
| 2006 | 16,540 |
| 2007 | 17,003 |
| 2008 | 16,561 |
| 2009 | 16,297 |
| 2010 | 15,946 |
| 2011 | 16,023 |
| 2012 | 15,714 |
| 2013 | 15,786 |
| 2014 | 16,197 |
| 2015 | 16,439 |
| 2016 | 16,954 |
| 2017 | 17,239 |
| 2018 | 18,189 |
| 2019 | 18,981 |
| 2020 | 13,447 |
| 2021 | 15,324 |
| 2022 | 17,613 |
| 2023 | 19,965 |
| 2024 | 20,060 |
| 2025 | 20,430 |
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, 0 of the 5 count points were counted; DfT estimated the rest from earlier counts and local trends.
M48 collisions
Police recorded 28 collisions with the M48 as the first road from 2021 to 2025, 8 of them fatal or serious. That is 6.3 per 100 million vehicle miles, higher than the 4.9 for all motorways in Great Britain. On average there were 0.4 a year for each mile of road.
Reported collisions by year
Down 14.3% from 2021 to 2025.
| Year | Collisions |
|---|---|
| 2021 | 7 |
| 2022 | 3 |
| 2023 | 4 |
| 2024 | 8 |
| 2025 | 6 |
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 |
|---|---|
| J2 to M4 (23) Monmouthshire · 14 collisions | 7.8 |
Source:DfT STATS19,UK Motoring analysis 2021 to 2025 Updated
A further 6 collisions were recorded at junctions where the M48 was the second road; they are not in the figures above. Fatal or serious uses DfT’s adjusted serious figures. 100.0% of the collisions could be placed on a section. How we count collisions
Council areas on the M48
In route order. Each is the highway authority DfT files the count points under.
- South Gloucestershire
- Gloucestershire
- Monmouthshire
Planned closures on the M48 in England
National Highways has 4 planned closures on the M48 between 16 September 2026 and 30 September 2026, 2 of them starting in that period. 1 close a carriageway rather than a lane or slip road, and 2 start between 7pm and 6am.
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Lane or slip M48 eastbound Jct 2 to 1 Severn Bridge lane closure and 40mph limit 198/5-194/7
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Carriageway M48 eastbound Jct 2 to 1 Severn Bridge carriageway closure
-
Lane or slip M48 eastbound Jct 2 to Jct 1 contraflow 198/5-194/7
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Lane or slip M48 eastbound Jct 2 to Jct 1 contraflow 30 mph limit 198/5-194/7
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 | 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 | 28 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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