A-road

A315 traffic and collisions

The A315 is an A-road of 14.1 miles, from Westminster to Hounslow. This page covers its traffic at 23 DfT count points since 2000 and the collisions police recorded on it.

Last updated
Records analysed
23 count points in 2025
Methodology
View methodology
  • Traffic in 2025 77m vehicle miles
  • Average daily traffic 14,928 vehicles a day, both directions
  • Busiest section 21,172 A4204 to A3220
  • HGV share 1.9% of vehicle miles
  • Traffic since 2019 −6.9% same count points
  • Collisions, 2021 to 2025 1,107 301.6 per 100m vehicle miles

How busy is the A315?

On an average day in 2025, 14,928 vehicles passed each point on the A315, counting both directions. The busiest section is A4204 to A3220 (Kensington and Chelsea), with 21,172 a day; the quietest listed is A315 Studland St to A402 Goldhawk Rd, with 9,976.

Busiest sections, 2025

A4204 to A3220 carries 1.4 times the road’s average flow.

Sections of the A315 with the highest average daily flow, 2025
Section Vehicles a day
A4204 to A3220 Kensington and Chelsea · 0.7 mi · HGVs 2.7% 21,172
A3063 to A244 Hounslow · 1.2 mi · HGVs 2.2% 18,082
A312 to A30(T) Hounslow · 1.7 mi · HGVs 1.6% 16,863
B363 to A314 Hounslow · 0.7 mi · HGVs 1.2% 15,736
A4/A3216 to A4204 Westminster, Kensington and Chelsea · 1.4 mi · HGVs 3.6% 15,730
A205 to A3002 Hounslow · 0.9 mi · HGVs 1.3% 14,959
A3220 to A219/A4 Kensington and Chelsea, Hammersmith and Fulham · 1.0 mi · HGVs 1.3% 13,879
A3000 to A205 Hounslow · 0.9 mi · HGVs 2.2% 13,873
A316 to A3000 Hounslow · 0.5 mi · HGVs 1.4% 12,909
A3002 to A310 Hounslow · 0.8 mi · HGVs 2.1% 12,783

Source:DfT,UK Motoring analysis 2000 to 2025 Updated

Route

Westminster to Hounslow · 14.1 miles

Westminster Hounslow
Schematic route: each line joins the junctions at the ends of a DfT count point link.

A315 traffic and collisions by section

20 sections between junctions, in route order. Each is the average of its DfT count points, weighted by length. 1 short link roads and spurs (0.6 miles) count in the road’s totals but are not listed.

Show all 20 sections Tap a column heading to sort
Sections of the A315 in route order, 2025 traffic
#
1A4/A3216 to A4204Westminster, Kensington and Chelsea1.415,7303.6%−16.6%131364.1
2A4204 to A3220Kensington and Chelsea0.721,1722.7%−18.4%110403.2
3At A3220Kensington and Chelsea0.121,1722.7%−18.4%16
4A3220 to A219/A4Kensington and Chelsea, Hammersmith and Fulham1.013,8791.3%−12.9%121479.9
5A219/A306 to A315 Studland StHammersmith and Fulham0.511,9941.8%−12.2%85780.7
6A315 Studland St to A402 Goldhawk RdHammersmith and Fulham0.59,9761.2%−13.0%82904.4
7A402 to A316Hounslow0.315,9581.5%−9.6%19
8A316 to A3000Hounslow0.512,9091.4%−12.9%47400.8
9A3000 to A205Hounslow0.913,8732.2%−13.3%51224.4
10A205 to A3002Hounslow0.914,9591.3%+5.3%50237.3
11A3002 to A310Hounslow0.812,7832.1%−17.8%57302.6
12A310 to B363Hounslow0.710,6241.9%−20.0%41302.3
13At B363Hounslow0.217,2650.7%−3.0%21
14B363 to A314Hounslow0.715,7361.2%+8.2%72428.8
15Bell Rd to School Rd/High StHounslow0.414,7071.7%−13.5%13
16A3005/A314 to A3006Hounslow0.315,0791.4%−14.4%16
17A3006 to A3063Hounslow0.416,1060.9%+50.5%37
18A3063 to A244Hounslow1.218,0822.2%+12.4%62156.4
19A244 to A312Hounslow0.311,1012.4%−14.3%10
20A312 to A30(T)Hounslow1.716,8631.6%+3.5%66140.2

Vehicles a day is the average daily flow in 2025. “Since 2019” compares the same count points. Collisions are those with the A315 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.

A315 traffic by vehicle type

Cars and taxis make up 73.3% of the vehicle miles on the A315. HGVs account for 1.9%, rising to 3.6% on A4/A3216 to A4204.

Vehicle mix, 2025

Source:DfT,UK Motoring analysis 2000 to 2025 Updated

HGV share of traffic

HGVs as a share of vehicle miles on the A315, by year
Year HGV share
2000 2.4%
2001 2.7%
2002 2.3%
2003 2.3%
2004 2.6%
2005 2.7%
2006 2.6%
2007 2.5%
2008 2.6%
2009 2.4%
2010 2.6%
2011 2.7%
2012 3.2%
2013 3.3%
2014 3.1%
2015 3.1%
2016 3.0%
2017 2.8%
2018 2.5%
2019 2.0%
2020 2.0%
2021 2.0%
2022 2.1%
2023 2.1%
2024 2.0%
2025 1.9%

Source:DfT,UK Motoring analysis 2000 to 2025 Updated

A315 traffic trend

Traffic on the A315 came to 76.8 million vehicle miles in 2025. At the count points present in both years, it is down 6.9% on 2019, before the pandemic, and down 12.1% on 2015.

Vehicle miles a year

Like for like, traffic is down 36.8% on 2000.

Vehicle miles on the A315 each year, the whole road as it was that year
Year Vehicle miles
2000 116m
2001 110m
2002 108m
2003 107m
2004 108m
2005 105m
2006 105m
2007 105m
2008 96m
2009 94m
2010 91m
2011 86m
2012 84m
2013 84m
2014 85m
2015 87m
2016 86m
2017 84m
2018 86m
2019 83m
2020 64m
2021 70m
2022 73m
2023 73m
2024 75m
2025 77m

Source:DfT,UK Motoring analysis 2000 to 2025 Updated

Average daily flow

Average daily flow along the A315, weighted by link length, by year
Year Vehicles a day
2000 23,557
2001 22,408
2002 21,222
2003 21,115
2004 21,205
2005 20,592
2006 20,734
2007 20,718
2008 18,963
2009 18,268
2010 17,580
2011 16,683
2012 16,237
2013 16,251
2014 16,413
2015 16,984
2016 16,672
2017 16,368
2018 16,630
2019 16,029
2020 12,373
2021 13,572
2022 14,078
2023 14,090
2024 14,648
2025 14,928

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, 6 of the 23 count points were counted; DfT estimated the rest from earlier counts and local trends.

A315 collisions

Police recorded 1,107 collisions with the A315 as the first road from 2021 to 2025, 226 of them fatal or serious, including 4 fatal. That is 301.6 per 100 million vehicle miles, higher than the 31.5 for all A-roads in Great Britain. On average there were 15.7 a year for each mile of road.

Reported collisions by year

Down 11.7% from 2021 to 2025.

Police-reported collisions on the A315 by year: fatal or serious, and slight
Year SlightFatal or serious
2021 20129
2022 18241
2023 17749
2024 16956
2025 15251

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.

Collisions per 100 million vehicle miles by section of the A315, 2021 to 2025
Section Per 100m vehicle miles
A315 Studland St to A402 Goldhawk Rd Hammersmith and Fulham · 82 collisions 904.4
A219/A306 to A315 Studland St Hammersmith and Fulham · 85 collisions 780.7
A3220 to A219/A4 Kensington and Chelsea, Hammersmith and Fulham · 121 collisions 479.9
B363 to A314 Hounslow · 72 collisions 428.8
A4204 to A3220 Kensington and Chelsea · 110 collisions 403.2
A316 to A3000 Hounslow · 47 collisions 400.8
A4/A3216 to A4204 Westminster, Kensington and Chelsea · 131 collisions 364.1
A3002 to A310 Hounslow · 57 collisions 302.6

Source:DfT STATS19,UK Motoring analysis 2021 to 2025 Updated

A further 128 collisions were recorded at junctions where the A315 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 A315

In route order. Each is the highway authority DfT files the count points under.

  • Westminster
  • Kensington and Chelsea
  • Hammersmith and Fulham
  • Hounslow

Data sources and methodology

Datasets used on this page
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 23 count points in 2025 15 September 2026
Reported collisions Road safety open data (STATS19) Department for Transport
Derived statistics UK Motoring
2021 to 2025 1,107 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.