Data commentary

Data commentary

This section is intended to provide a useful interpretation of some of the key data in each RoadFile section, highlighting how the data may provide further insight/support investigations into road-related issues. Any reliance placed on the data and/or this interpretation is strictly at the user’s discretion. (see Guidance section)

Road network

The length of the GB road network remains constant with just a 0.12% increase reported in 2021 over 2020. Across the EU27 the road network grew by 0.34%.

Understandably, road-traffic (vehicle miles) were significantly lower in 2020 and 2021, than in previous years, due to Covid-19 related restrictions.. A 21% decline in all road traffic is reported in 2020 compared to 2019, with buses and coaches reporting a 33% drop. Car and taxi traffic fell by 25% in this period, while HGV traffic fell by the smallest percentage at just 6%.

  • The length of the GB road network has remained constant over the last decade. The latest figures report an increase of 298 miles in 2020 on 2019 data. It is likely that the increase relates predominantly to new roads on housing developments etc becoming adopted. (Please note the methodology used by the Department for Transport (DfT) for its classification of road length by road type has differed in some years. This has resulted in broader definitions of road types in 2013, 2014, 2017 and 2019, which is why there are no road lengths reported for C and U roads in these years – with these road lengths accounted for by the DfT under the ‘all minor roads’ category.)
  • The UK is ranked 13th out of 28 European counties in terms of motorway density per 1,000km2.
  • The European average for the number of cars per km of motorway is 3,417. In the UK, this figure is more than twice as high – with x 8,743 cars per km of motorway, indicating that GB motorways are more heavily trafficked, by cars, than the European average.

GB Regional Data

GB traffic volume (billion miles) increased by 16.6% between 2010-2019, with the North East reporting the highest regional increases. In 2020, volume dropped by 25% due to the pandemic, but by 2021 had returned to 83% of pre-pandemic levels recorded in 2019.

  • The motorway network across England, Scotland and Wales increased by 110 miles (4.9%) between 2010-2021. In England, this was mostly as a result of the reclassification/upgrading of some A roads. See
  • Scotland saw the largest change in miles of motorway in the period 2010-2021. In Wales there was no change.
  • Yorkshire and Humber and the North East experienced the largest growth in major road lengths –up 3.5% between 2010-2021.
  • The growth in Ultra Low Emission Vehicles (ULEVs) on GB roads continues – rising from 79,747 in 2019, to more than 317,101 in 2021.
  • The number of battery electric cars has multiplied more than 18 times since 2015. The number of public charging points increased by a factor of eight.

Road usage

The impact of Covid-19 is apparent across all modes of Britain’s transport, with passenger miles per km reported in 2021 remaining more than a third down on pre-pandemic levels.

However, the picture is more nuanced when reviewing the data for different modes of transport:

  • Passenger journeys by Rail in 2021 were 80% down on 2019 figures, reflecting the impact of the shift to working from home as well as intermittent on-going travel restrictions.
  • Similarly, air travel also remained significantly down due to restrictions on international travel.
  • In contrast, passenger miles across all types of road vehicle, while still down on pre-pandemic levels, were 28% less in 2021, than reported in 2019.  
  • The DfT defines the difference between freight moved and freight lifted as follows: “Freight activity is either measured in terms of the weight of goods (tonnes) carried, taking no account of the distance they are carried (termed ‘goods lifted’), or as ‘goods moved’ (tonne kilometres) which does take into account distance. ‘Goods moved’ for each loaded journey is the weight of the load multiplied by the distance it is carried, and therefore a better measure of the activity done by heavy goods vehicles.” See
  • Latest figures show that, in 2020 there was an 11.6% decline in goods moved.
  • The data (Average number of trips per person per year by mode in England) highlights a big increase in the number of people switching to walks of more than a mile during 2020. Although these figures subsequently fell back in 2021, no doubt with the lifting of Covid-19 restrictions, they remained 26% higher than in 2019.
  • The spike in bicycling reported in 2020 (up 26.2%) was not sustained in 2021, indicating the continued challenges facing policy makers in making the shift to active modes of travel permanent.

Traffic volume

The growth in the number of licensed light commercial vehicles continues to outpace the growth in the number of other types of vehicles.  

  • There were 14% more new licensed vehicles on GB roads in 2021 than in 2011, including 39,000 more HGVs and more than 1,150,000 light commercial vehicles.
  • The number of licensed HGVs dipped in 2020 by 3.1% on 2019 figures but had more than bounced back by 2022.
  • The number of light commercial vehicles grew by 7% between 2019-2021. In comparison the number of cars grew by just 0.3%.
  • Overall traffic (billion vehicle miles by road class) remained 12% down in 2021 than, pre-pandemic in 2019.
  • Motorway traffic remained down by 14.4% in 2021, compared to 2019. In contrast traffic volume remained down by 8.8% over the same period.


CO2 emissions from vehicles peaked in 2017, falling 22% between 2017-2020.

  • There was a 19.3% drop in the CO2 emissions from vehicles between 2019 and 2020 –exceeding the 12% drop in traffic volumes reported over the same period, thereby suggesting that vehicles on the road continue to emit less/are cleaner.
  • This is supported by the continued growth in the number of Ultra Low Emission Vehicles (ULEVs) on GB roads which increased by 71% between 2020-2021.
  • The reasons for the spike in fuel prices in recent years are well-known, including the impact of the war in Ukraine, rising inflation etc. Petrol prices reported in 2022 were 28.8% higher than the previous year.
  • In 2012 57.5% of the petrol pump price comprised of taxes – rising to a peak of 80.75% in 2013. In 2022 49.4% of the petrol pump price comprised of taxes.


The number of fatal or serious accidents recorded on UK roads fell in 2020, mirroring the decline in traffic etc as a result of restrictions introduced due to the pandemic. However, since 2012 the overarching trend is one of a steady increase in the number of both fatal and serious accidents across all road types. 

  • The number of accidents of all severities on Britain’s motorways and A Roads fell by 22% between 2010 – 2019.
  • In contrast the number of accidents of all severities on non- A roads has increased by 13% across the same timeframe.
  • France, Germany, Italy, Poland, Romania and Turkey all reported a higher number of road fatalities than the UK in 2020.

Road User Charging

Across the former EU28, only The Netherlands generates less income than the UK from road user charging.

  • The net income generated by the London Congestion Charge has increased 223% since the first year it was introduced in 2003/4.
  • In 2018-19 Transport for London (TfL) received £146.7 million net income from the London Congestion Charge.


In 2022, for every £ from the public purse spent on the UK’s railways, 45p was spent on roads.

Guidance notes:

  • Transport is a devolved issue in the UK with the devolved Governments for Wales, Scotland and Northern Ireland having responsibility for many transport-related policy and operational issues. See
  • The term Britain used across RoadFile refers to Great Britain (GB), including Scotland and Wales, but excluding Northern Ireland. All figures relate to GB unless otherwise stated.
    • All Department for Transport (DfT) figures relate to GB unless otherwise stated.

    • The Asphalt Industry’s Annual Local Road Maintenance (ALARM) survey covers England, Wales and London.

    • Eurostat data includes the former EU 28 with its data for the UK covering Great Britain (England, Scotland and Wales) and Northern Ireland.

  • Freight data refers to domestic road freight transport by goods vehicles over 3.5 tonnes gross weight.
  • Disclaimer: While we have used our reasonable efforts to ensure the accuracy of the data used in this website, RoadFile, its associated organisations and/or their employees do not assume any legal liability or responsibility for the accuracy, or completeness of any information provided. The burden of fitness of the data lies completely with the user.

Further sources of information: