A-road

A251 traffic and collisions

The A251 is an A-road of 11.8 miles, in Kent. This page covers its traffic at 5 DfT count points since 2000 and the collisions police recorded on it.

Last updated
Records analysed
5 count points in 2025
Methodology
View methodology
  • Traffic in 2025 43m vehicle miles
  • Average daily traffic 9,936 vehicles a day, both directions
  • Busiest section 12,651 A2 to M2
  • HGV share 2.6% of vehicle miles
  • Traffic since 2019 +5.6% same count points
  • Collisions, 2021 to 2025 67 33.5 per 100m vehicle miles

How busy is the A251?

On an average day in 2025, 9,936 vehicles passed each point on the A251, counting both directions. The busiest section is A2 to M2 (Kent), with 12,651 a day; the quietest listed is Shottenden Rd to A252, with 8,691.

Busiest sections, 2025

A2 to M2 carries 1.3 times the road’s average flow.

Sections of the A251 with the highest average daily flow, 2025
Section Vehicles a day
A2 to M2 Kent · 0.6 mi · HGVs 4.5% 12,651
M2 to Shottenden Rd Kent · 4.3 mi · HGVs 2.2% 11,308
M20 to A2042 Faversham Rd Kent · 1.3 mi · HGVs 2.1% 9,490
A252 to Trinity Rd, Ashford Kent · 4.0 mi · HGVs 2.8% 8,696
Shottenden Rd to A252 Kent · 1.6 mi · HGVs 3.0% 8,691

Source:DfT,UK Motoring analysis 2000 to 2025 Updated

Route

In Kent · 11.8 miles

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

A251 traffic and collisions by section

5 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
Sections of the A251 in route order, 2025 traffic
#
1A2 to M2Kent0.612,6514.5%+17.2%7
2M2 to Shottenden RdKent4.311,3082.2%+6.0%2328.8
3Shottenden Rd to A252Kent1.68,6913.0%+2.3%1042.2
4A252 to Trinity Rd, AshfordKent4.08,6962.8%+8.5%2134.5
5M20 to A2042 Faversham RdKent1.39,4902.1%−5.2%6

Vehicles a day is the average daily flow in 2025. “Since 2019” compares the same count points. Collisions are those with the A251 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.

A251 traffic by vehicle type

Cars and taxis make up 76.2% of the vehicle miles on the A251. HGVs account for 2.6%, rising to 4.5% on A2 to M2.

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 A251, by year
Year HGV share
2000 4.3%
2001 4.3%
2002 4.5%
2003 4.4%
2004 4.6%
2005 3.5%
2006 3.5%
2007 3.7%
2008 3.7%
2009 3.4%
2010 3.4%
2011 3.5%
2012 3.5%
2013 3.4%
2014 3.4%
2015 3.3%
2016 3.2%
2017 3.2%
2018 3.3%
2019 3.3%
2020 3.8%
2021 3.6%
2022 3.4%
2023 3.2%
2024 2.6%
2025 2.6%

Source:DfT,UK Motoring analysis 2000 to 2025 Updated

A251 traffic trend

Traffic on the A251 came to 42.8 million vehicle miles in 2025. At the count points present in both years, it is up 5.6% on 2019, before the pandemic, and up 13.4% on 2015.

Vehicle miles a year

Like for like, traffic is up 59.3% on 2000.

Vehicle miles on the A251 each year, the whole road as it was that year
Year Vehicle miles
2000 24m
2001 26m
2002 31m
2003 31m
2004 31m
2005 33m
2006 34m
2007 34m
2008 33m
2009 33m
2010 33m
2011 35m
2012 35m
2013 35m
2014 36m
2015 37m
2016 39m
2017 40m
2018 40m
2019 41m
2020 31m
2021 36m
2022 39m
2023 40m
2024 42m
2025 43m

Source:DfT,UK Motoring analysis 2000 to 2025 Updated

Average daily flow

Average daily flow along the A251, weighted by link length, by year
Year Vehicles a day
2000 6,270
2001 6,955
2002 7,211
2003 7,211
2004 7,250
2005 7,617
2006 7,882
2007 8,050
2008 7,825
2009 7,777
2010 7,719
2011 8,176
2012 8,085
2013 8,266
2014 8,493
2015 8,757
2016 9,225
2017 9,299
2018 9,327
2019 9,407
2020 7,171
2021 8,348
2022 9,003
2023 9,273
2024 9,825
2025 9,936

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.

A251 collisions

Police recorded 67 collisions with the A251 as the first road from 2021 to 2025, 20 of them fatal or serious, including 4 fatal. That is 33.5 per 100 million vehicle miles, close to the 31.5 for all A-roads in Great Britain. On average there were 1.1 a year for each mile of road.

Reported collisions by year

Down 33.3% from 2021 to 2025.

Police-reported collisions on the A251 by year
Year Collisions
2021 12
2022 14
2023 21
2024 12
2025 8

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 A251, 2021 to 2025
Section Per 100m vehicle miles
Shottenden Rd to A252 Kent · 10 collisions 42.2
A252 to Trinity Rd, Ashford Kent · 21 collisions 34.5
M2 to Shottenden Rd Kent · 23 collisions 28.8

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

A further 3 collisions were recorded at junctions where the A251 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 A251

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

  • Kent

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 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 67 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.