A-road
A3102 traffic and collisions
The A3102 is an A-road of 24.9 miles, from Swindon to Wiltshire. This page covers its traffic at 12 DfT count points since 2000 and the collisions police recorded on it.
- Traffic in 2025 120m vehicle miles
- Average daily traffic 13,165 vehicles a day, both directions
- Busiest section 29,575 M4 to B4042
- HGV share 3.2% of vehicle miles
- Traffic since 2019 −4.4% same count points
- Collisions, 2021 to 2025 218 38.9 per 100m vehicle miles
How busy is the A3102?
On an average day in 2025, 13,165 vehicles passed each point on the A3102, counting both directions. The busiest section is M4 to B4042 (Wiltshire), with 29,575 a day; the quietest listed is White Horse Way, Calne to A342, with 5,755.
Busiest sections, 2025
M4 to B4042 carries 2.2 times the road’s average flow.
| Section | Vehicles a day |
|---|---|
| M4 to B4042 Wiltshire · 2.3 mi · HGVs 3.2% | 29,575 |
| B4006 to M4 J16 Swindon · 2.4 mi · HGVs 3.6% | 25,528 |
| B4289 to B4006 Swindon · 0.7 mi · HGVs 0.5% | 24,188 |
| B3104 to A350 Wiltshire · 0.7 mi · HGVs 0.8% | 16,324 |
| roundabout SW of Lickhill Rd to A4 Wiltshire · 0.6 mi · HGVs 3.2% | 13,869 |
| B4042 to Whitehill Lane Wiltshire · 1.1 mi · HGVs 3.2% | 12,422 |
| Whitehill Lane to B4069 Wiltshire · 3.4 mi · HGVs 3.6% | 10,718 |
| B4069 to roundabout SW of Lickhill Rd Wiltshire · 5.7 mi · HGVs 3.5% | 10,118 |
| Churchill Avenue to B3104 Wiltshire · 0.9 mi · HGVs 1.2% | 8,244 |
| A342 to Churchill Ave, Melksham Wiltshire · 3.9 mi · HGVs 4.2% | 7,203 |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
Route
Swindon to Wiltshire · 24.9 miles
A3102 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 | B4289 to B4006Swindon | 24,188 | 35 |
| 2 | B4006 to M4 J16Swindon | 25,528 | 24 |
| 3 | M4 to B4042Wiltshire | 29,575 | 41 |
| 4 | B4042 to Whitehill LaneWiltshire | 12,422 | 16 |
| 5 | Whitehill Lane to B4069Wiltshire | 10,718 | 22 |
| 6 | B4069 to roundabout SW of Lickhill RdWiltshire | 10,118 | 33 |
| 7 | roundabout SW of Lickhill Rd to A4Wiltshire | 13,869 | fewer than 3 |
| 8 | A4 to White Horse WayWiltshire | 6,388 | 4 |
| 9 | White Horse Way, Calne to A342Wiltshire | 5,755 | 10 |
| 10 | A342 to Churchill Ave, MelkshamWiltshire | 7,203 | 13 |
| 11 | Churchill Avenue to B3104Wiltshire | 8,244 | 10 |
| 12 | B3104 to A350Wiltshire | 16,324 | 9 |
Vehicles a day is the average daily flow in 2025. “Since 2019” compares the same count points. Collisions are those with the A3102 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.
A3102 traffic by vehicle type
Cars and taxis make up 78.4% of the vehicle miles on the A3102. HGVs account for 3.2%.
Vehicle mix, 2025
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
HGV share of traffic
| Year | HGV share |
|---|---|
| 2000 | 5.2% |
| 2001 | 6.1% |
| 2002 | 5.4% |
| 2003 | 5.4% |
| 2004 | 5.4% |
| 2005 | 5.1% |
| 2006 | 5.4% |
| 2007 | 5.1% |
| 2008 | 4.8% |
| 2009 | 4.4% |
| 2010 | 4.5% |
| 2011 | 4.3% |
| 2012 | 4.4% |
| 2013 | 4.3% |
| 2014 | 4.4% |
| 2015 | 4.3% |
| 2016 | 4.4% |
| 2017 | 4.4% |
| 2018 | 3.8% |
| 2019 | 3.9% |
| 2020 | 4.4% |
| 2021 | 4.2% |
| 2022 | 3.8% |
| 2023 | 3.5% |
| 2024 | 3.3% |
| 2025 | 3.2% |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
A3102 traffic trend
Traffic on the A3102 came to 120 million vehicle miles in 2025. At the count points present in both years, it is down 4.4% on 2019, before the pandemic, and up 4.4% on 2015.
Vehicle miles a year
Like for like, traffic is up 12.5% on 2000.
| Year | Vehicle miles |
|---|---|
| 2000 | 104m |
| 2001 | 103m |
| 2002 | 104m |
| 2003 | 102m |
| 2004 | 105m |
| 2005 | 103m |
| 2006 | 107m |
| 2007 | 103m |
| 2008 | 103m |
| 2009 | 103m |
| 2010 | 99m |
| 2011 | 100m |
| 2012 | 99m |
| 2013 | 100m |
| 2014 | 105m |
| 2015 | 108m |
| 2016 | 112m |
| 2017 | 109m |
| 2018 | 118m |
| 2019 | 119m |
| 2020 | 92m |
| 2021 | 101m |
| 2022 | 111m |
| 2023 | 114m |
| 2024 | 115m |
| 2025 | 120m |
Source:DfT,UK Motoring analysis 2000 to 2025 Updated
Average daily flow
| Year | Vehicles a day |
|---|---|
| 2000 | 11,955 |
| 2001 | 11,802 |
| 2002 | 11,866 |
| 2003 | 11,738 |
| 2004 | 12,022 |
| 2005 | 11,815 |
| 2006 | 12,281 |
| 2007 | 11,801 |
| 2008 | 11,827 |
| 2009 | 11,819 |
| 2010 | 11,302 |
| 2011 | 11,503 |
| 2012 | 11,380 |
| 2013 | 11,512 |
| 2014 | 12,068 |
| 2015 | 12,385 |
| 2016 | 12,800 |
| 2017 | 12,394 |
| 2018 | 13,145 |
| 2019 | 13,166 |
| 2020 | 10,145 |
| 2021 | 11,201 |
| 2022 | 12,319 |
| 2023 | 12,626 |
| 2024 | 12,787 |
| 2025 | 13,165 |
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, 2 of the 12 count points were counted; DfT estimated the rest from earlier counts and local trends.
A3102 collisions
Police recorded 218 collisions with the A3102 as the first road from 2021 to 2025, 49 of them fatal or serious, including 3 fatal. That is 38.9 per 100 million vehicle miles, higher than the 31.5 for all A-roads in Great Britain. On average there were 1.8 a year for each mile of road.
Reported collisions by year
Down 2.3% from 2021 to 2025.
| Year | Slight | Fatal or serious |
|---|---|---|
| 2021 | 36 | 7 |
| 2022 | 35 | 12 |
| 2023 | 34 | 8 |
| 2024 | 32 | 12 |
| 2025 | 32 | 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 |
|---|---|
| M4 to B4042 Wiltshire · 41 collisions | 165.1 |
| B4289 to B4006 Swindon · 35 collisions | 118.8 |
| Churchill Avenue to B3104 Wiltshire · 10 collisions | 76.1 |
| B4042 to Whitehill Lane Wiltshire · 16 collisions | 61.4 |
| Whitehill Lane to B4069 Wiltshire · 22 collisions | 34.4 |
| White Horse Way, Calne to A342 Wiltshire · 10 collisions | 32.8 |
| B4069 to roundabout SW of Lickhill Rd Wiltshire · 33 collisions | 32.6 |
| A342 to Churchill Ave, Melksham Wiltshire · 13 collisions | 26.4 |
Source:DfT STATS19,UK Motoring analysis 2021 to 2025 Updated
A further 22 collisions were recorded at junctions where the A3102 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 A3102
In route order. Each is the highway authority DfT files the count points under.
- Swindon
- Wiltshire
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 | 12 count points in 2025 | 15 September 2026 |
| Reported collisions | Road safety open data (STATS19) Department for Transport Derived statistics UK Motoring | 2021 to 2025 | 218 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.