A-road

A358 traffic and collisions

The A358 is an A-road of 43.2 miles, from Devon to Somerset. This page covers its traffic at 18 DfT count points since 2000 and the collisions police recorded on it.

Last updated
Records analysed
18 count points in 2025
Methodology
View methodology
  • Traffic in 2025 218m vehicle miles
  • Average daily traffic 13,805 vehicles a day, both directions
  • Busiest section 47,527 M5 to A38
  • HGV share 4.5% of vehicle miles
  • Traffic since 2019 −1.7% same count points
  • Collisions, 2021 to 2025 207 20.1 per 100m vehicle miles

How busy is the A358?

On an average day in 2025, 13,805 vehicles passed each point on the A358, counting both directions. The busiest section is M5 to A38 (Somerset), with 47,527 a day; the quietest listed is B3224 to A39, with 7,030.

Busiest sections, 2025

M5 to A38 carries 3.4 times the road’s average flow.

Sections of the A358 with the highest average daily flow, 2025
Section Vehicles a day
M5 to A38 Somerset · 0.9 mi · HGVs 2.3% 47,527
M5 J25 to Junction A378/A358 Somerset · 2.8 mi · HGVs 6.7% 30,720
A38 to A3259 Somerset · 0.6 mi · HGVs 2.3% 25,139
A303 to A378 Somerset · 6.5 mi · HGVs 7.3% 22,759
A3027 to A3065 Somerset · 0.6 mi · HGVs 1.9% 22,479
A3259 to A3038 roundabout Somerset · 0.7 mi · HGVs 2.0% 16,798
B3227 to Dene Road roundabout Somerset · 2.2 mi · HGVs 3.3% 13,765
Thorndun Park Drive to A30 Somerset · 2.1 mi · HGVs 3.7% 13,702
Dene Road roundabout to B3224 Somerset · 1.7 mi · HGVs 2.6% 12,023
A30 to Thorndun Park Drive Somerset · 0.9 mi · HGVs 3.3% 10,843

Source:DfT,UK Motoring analysis 2000 to 2025 Updated

Route

Devon to Somerset · 43.2 miles

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

A358 traffic and collisions by section

18 sections between junctions, in route order. Each is the average of its DfT count points, weighted by length.

Show all 18 sections Tap a column heading to sort
Sections of the A358 in route order, 2025 traffic
#
1A3052 to A358 spurDevon3.67,7661.5%+12.7%1634.8
2A358 spur to B3167Devon4.87,5083.2%−6.0%2539.6
3B3167 to HalcombeSomerset2.68,2402.5%+12.9%1235.5
4Halcombe to A30Somerset0.79,6612.2%+14.2%4
5A30 to Thorndun Park DriveSomerset0.910,8433.3%−4.7%7
6Thorndun Park Drive to A30Somerset2.113,7023.7%+22.4%6
7C road to Dowlish Ford to A303Somerset2.19,7855.9%+13.4%fewer than 3
8A303 to A378Somerset6.522,7597.3%−3.8%2610.0
9M5 J25 to Junction A378/A358Somerset2.830,7206.7%2117.1
10M5 to A38Somerset0.947,5272.3%+1.0%1723.0
11A38 to A3259Somerset0.625,1392.3%−5.4%8
12A3259 to A3038 roundaboutSomerset0.716,7982.0%−16.8%5
13A3038 roundabout to A3027Somerset0.810,2093.4%−34.0%5
14A3027 to A3065Somerset0.622,4791.9%+5.1%fewer than 3
15A3065 to B3227Somerset0.123,7395.7%+3.3%0
16B3227 to Dene Road roundaboutSomerset2.213,7653.3%−10.0%1630.1
17Dene Road roundabout to B3224Somerset1.712,0232.6%+0.3%9
18B3224 to A39Somerset9.57,0302.1%−6.8%2723.1

Vehicles a day is the average daily flow in 2025. “Since 2019” compares the same count points. Collisions are those with the A358 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.

A358 traffic by vehicle type

Cars and taxis make up 77.6% of the vehicle miles on the A358. HGVs account for 4.5%, rising to 7.3% on A303 to A378.

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 A358, by year
Year HGV share
2000 6.4%
2001 6.6%
2002 6.9%
2003 6.1%
2004 6.0%
2005 5.7%
2006 5.5%
2007 5.9%
2008 5.7%
2009 5.4%
2010 5.3%
2011 5.2%
2012 5.1%
2013 4.9%
2014 4.9%
2015 5.2%
2016 5.0%
2017 5.0%
2018 5.0%
2019 5.0%
2020 6.3%
2021 6.2%
2022 5.6%
2023 4.7%
2024 4.5%
2025 4.5%

Source:DfT,UK Motoring analysis 2000 to 2025 Updated

A358 traffic trend

Traffic on the A358 came to 218 million vehicle miles in 2025. At the count points present in both years, it is down 1.7% on 2019, before the pandemic, and up 2.5% on 2015.

Vehicle miles a year

Like for like, traffic is up 9.1% on 2000.

Vehicle miles on the A358 each year, the whole road as it was that year
Year Vehicle miles
2000 193m
2001 194m
2002 200m
2003 199m
2004 196m
2005 201m
2006 199m
2007 198m
2008 201m
2009 204m
2010 201m
2011 202m
2012 202m
2013 201m
2014 199m
2015 204m
2016 212m
2017 216m
2018 217m
2019 218m
2020 166m
2021 183m
2022 205m
2023 210m
2024 215m
2025 218m

Source:DfT,UK Motoring analysis 2000 to 2025 Updated

Average daily flow

Average daily flow along the A358, weighted by link length, by year
Year Vehicles a day
2000 12,331
2001 12,429
2002 12,823
2003 12,710
2004 12,517
2005 12,852
2006 12,746
2007 12,648
2008 12,868
2009 13,074
2010 12,878
2011 12,937
2012 12,896
2013 12,838
2014 12,758
2015 13,055
2016 13,598
2017 13,854
2018 13,872
2019 13,932
2020 10,622
2021 11,698
2022 12,970
2023 13,308
2024 13,661
2025 13,805

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 18 count points were counted; DfT estimated the rest from earlier counts and local trends.

A358 collisions

Police recorded 207 collisions with the A358 as the first road from 2021 to 2025, 63 of them fatal or serious, including 4 fatal. That is 20.1 per 100 million vehicle miles, lower than the 31.5 for all A-roads in Great Britain. On average there were 1.0 a year for each mile of road.

Reported collisions by year

Up 37.1% from 2021 to 2025.

Police-reported collisions on the A358 by year: fatal or serious, and slight
Year SlightFatal or serious
2021 2213
2022 2113
2023 3711
2024 2913
2025 3513

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 A358, 2021 to 2025
Section Per 100m vehicle miles
A358 spur to B3167 Devon · 25 collisions 39.6
B3167 to Halcombe Somerset · 12 collisions 35.5
A3052 to A358 spur Devon · 16 collisions 34.8
B3227 to Dene Road roundabout Somerset · 16 collisions 30.1
B3224 to A39 Somerset · 27 collisions 23.1
M5 to A38 Somerset · 17 collisions 23.0
M5 J25 to Junction A378/A358 Somerset · 21 collisions 17.1
A303 to A378 Somerset · 26 collisions 10.0

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

A further 30 collisions were recorded at junctions where the A358 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 A358

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

  • Devon
  • Somerset

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 18 count points in 2025 15 September 2026
Reported collisions Road safety open data (STATS19) Department for Transport
Derived statistics UK Motoring
2021 to 2025 207 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.