Road goods vehicles travelling to Europe: Revisions to published data from January 2022 to December 2023
Published 14 May 2025
© Crown copyright 2025
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This publication is available at https://www.gov.uk/government/statistics/road-goods-vehicles-travelling-to-europe-2024/road-goods-vehicles-travelling-to-europe-revisions-to-published-data-from-january-2022-to-december-2023
1. Introduction
This report summarises the outcome of a quality review of information provided by ferry operators to the Department for Transport (DfT) for the Road Goods Vehicles Travelling to Europe (RoRo) publication.
When quality checking the data in Autumn 2024, it became evident that the data provided by some ferry operators from January 2022 to December 2023 for specific routes were not consistent with RoRo definitions and guidance.
This report summarises these revisions which have been implemented in the Road Goods Vehicles Travelling to Europe: 2024 statistical publication.
We are grateful to receive any feedback on this topic, which can be given at roadfreight.stats@dft.gov.uk.
2. Background
The RoRo census is designed to collect information on road goods vehicles travelling by ferry and Channel Tunnel from Great Britain (GB) to Europe. The census covers trips by powered heavy goods vehicles (HGVs) that weigh more than 3.5 tonnes, and unaccompanied trailers not accompanied by a powered unit.
Whilst undertaking the standard quality review of the data supplied for 2024 quarter 2 (April to June) it became evident there were some issues with data from some operators. Upon further investigation of the supplied 2024 Q2 data, it became apparent that the data did not comply with agreed RoRo definitions. There were inconsistencies in the reported data for powered vehicles due to differences in how certain operators recorded their figures.
Following the discovery of these discrepancies, investigations were conducted to determine the cause and timing of the issue.
The data supplied was only meant to reflect ferry manifest data (the actual volume carried). The investigation indicated a misunderstanding of the reporting requirements, where some figures were based on booking data rather than actual carried volume. This resulted in some instances where vehicles were counted multiple times and others where they were omitted. The inconsistencies affected published data from January 2022 up to December 2023.
As the issue had led to both overcounting and undercounting, it had only been identifiable in the 2024 quarter 2 data.
The suppliers have re-provided data for January 2022 up to December 2023, ensuring that only vehicles falling within the correct definitions are now included in the data supply.
We have also taken this opportunity to confirm with all our suppliers of RoRo data that the information they supply adheres to the correct RoRo definitions, including:
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the classification of vehicles to be included in reported numbers
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the classification of the vehicle country of registration
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the direction of traffic reported
3. Summary of changes
Definition
Quarter: a calendar year quarter. In this publication, quarter 1 refers to January to March, quarter 2 refers to April to June, quarter 3 refers to July to September, and quarter 4 refers to October to December.
Note: Figures are rounded to the nearest thousand. Figures may not sum due to rounding.
The total impact of the revision to data from January 2022 to December 2023 was an increase of 31 thousand trips made by all vehicles (0.5%), from 5.858 million trips to 5.890 million trips.
The largest impact has been on the reported number of powered vehicles, with an increase of 30 thousand trips (0.8%) seen across the period.
The most substantial changes between the original and revised figures occurred in the latter half of 2023, particularly in quarter 4 where the revised figure for powered vehicle trips increased by 65 thousand (15.9%). Earlier periods from January 2022 to December 2022 saw downward revisions of up to 5.5%.
Over this 2 year period, foreign-registered powered vehicles saw a drop of 198 thousand trips (6.7%), and UK-registered powered vehicles saw a fall of 20 thousand trips (3.7%) between the original and revised figures. However the overall number of trips taken by powered vehicles with an unknown country of registration saw a large increase of 247 thousand trips (82%) between the original and revised figures. Despite the decline seen in overall number of UK and foreign-registered powered vehicles trips, this was offset by the increase in powered vehicles of unknown country of registration. This resulted in the overall increase of 30 thousand powered vehicle trips between the original and revised data.
Unaccompanied trailers remained largely unchanged, with a minor increase of 2 thousand trips (0.1%) across the period.
The tables below show the effect of these revisions for each quarter in the period January 2022 to December 2023. In our 2024 annual publication, we have updated the data covering the period January 2022 to December 2023 to reflect the revised data, as well as releasing the 2024 quarterly data which were delayed in publishing while conducting this investigation.
4. All vehicles
Definition
All vehicles: the sum of powered heavy goods vehicles and unaccompanied trailers.
The impact of the revisions on the total number of trips made by all vehicles across the period January 2022 to December 2023 saw a net change of 31 thousand trips from 5.858 million trips to 5.890 million trips (0.5%). The largest contributor to the marginal rise in total vehicle numbers was the increase in the number of powered vehicles as shown in section 5 below.
Table 1 shows the effect of these revisions on the total number of trips being made by all vehicles across the period January 2022 to December 2023. The largest change between the original and revised figures was an increase of 10.1% in 2023 quarter 4.
Table 1: Impact of revisions on the total number of trips made by all vehicles, 2022 Q1 to 2023 Q4
| Year and Quarter | Original | Revised | Difference | % change |
|---|---|---|---|---|
| 2022 Q1 | 770,000 | 760,000 | -17,000 | -2.1% |
| 2022 Q2 | 790,000 | 762,000 | -28,000 | -3.5% |
| 2022 Q3 | 746,000 | 734,000 | -12,000 | -1.6% |
| 2022 Q4 | 762,000 | 743,000 | -19,000 | -2.5% |
| 2023 Q1 | 709,000 | 721,000 | 12,000 | 1.7% |
| 2023 Q2 | 727,000 | 737,000 | 10,000 | 1.4% |
| 2023 Q3 | 699,000 | 718,000 | 19,000 | 2.8% |
| 2023 Q4 | 650,000 | 715,000 | 65,000 | 10.1% |
| Total trips | 5,858,000 | 5,890,000 | 31,000 | 0.5% |
Chart 1: Number of trips made by all vehicles travelling from GB to Europe before and after applying revisions, 2020 Q1 to 2023 Q4
5. Powered Vehicles
Definition
Powered vehicles: are heavy goods vehicles (HGVs) that weigh more than 3.5 tonnes and can be driven by a driver. This includes rigid lorries, tractors and trailers (counted as 1 unit) and tractive units only.
The largest changes in magnitude seen in the revised data were for powered vehicles. However, both the original and revised data show a downward quarter on quarter trend between January 2022 and September 2023. The original series continued to fall in quarter 4 2023, whereas the revised data saw an increase on the previous quarter in quarter 4 2023.
Table 2 shows the effect of these revisions on the total number of trips made by powered vehicles across the period January 2022 to December 2023. The net change across this period was an increase of 30 thousand trips by powered vehicles (0.8%), from 3.762 million trips to 3.792 million trips. The largest change between the original and revised numbers was seen in 2023 quarter 4 (15.9%).
Table 2: Impact of revisions on the total number of trips made by powered vehicles, 2022 Q1 to 2023 Q4
| Year and Quarter | Original | Revised | Difference | % change |
|---|---|---|---|---|
| 2022 Q1 | 511,000 | 494,000 | -17,000 | -3.3% |
| 2022 Q2 | 511,000 | 483,000 | -28,000 | -5.5% |
| 2022 Q3 | 474,000 | 462,000 | -12,000 | -2.6% |
| 2022 Q4 | 498,000 | 479,000 | -19,000 | -3.8% |
| 2023 Q1 | 458,000 | 469,000 | 12,000 | 2.6% |
| 2023 Q2 | 464,000 | 474,000 | 10,000 | 2.1% |
| 2023 Q3 | 439,000 | 458,000 | 19,000 | 4.4% |
| 2023 Q4 | 408,000 | 473,000 | 65,000 | 15.9% |
| Total trips | 3,762,000 | 3,792,000 | -30,000 | 0.8% |
Chart 2: Number of trips made by powered vehicles travelling from GB to Europe before and after applying revisions, 2020 Q1 to 2023 Q4
6. Unaccompanied trailers
Definition
Unaccompanied trailers: include tow-bar trailers and articulated semi-trailers, not accompanied on the ferry by a powered unit.
The number of unaccompanied trailers trips remained largely unchanged following the revisions, with only minor adjustments observed.
Table 3 shows the effect of these revisions on the total number of trips made by unaccompanied trailers across the period January 2022 and December 2023. The net change across this period was a slight increase of 2 thousand trips by unaccompanied trailers (0.1%), from 2.096 million trips to 2.098 million trips. The revisions resulted in little or no changes between original and revised figures across all quarters.
Table 3: Impact of revisions on the total number of trips made by unaccompanied trailers, 2022 Q1 to 2023 Q4
| Year and Quarter | Original | Revised | Difference | % change |
|---|---|---|---|---|
| 2022 Q1 | 266,000 | 266,000 | 0 | 0.1% |
| 2022 Q2 | 279,000 | 279,000 | 0 | 0.1% |
| 2022 Q3 | 272,000 | 272,000 | 0 | 0.1% |
| 2022 Q4 | 264,000 | 264,000 | 0 | 0.0% |
| 2023 Q1 | 252,000 | 252,000 | 0 | 0.1% |
| 2023 Q2 | 263,000 | 263,000 | 0 | 0.0% |
| 2023 Q3 | 260,000 | 260,000 | 0 | 0.0% |
| 2023 Q4 | 241,000 | 242,000 | 1,000 | 0.2% |
| Total trips | 2,096,000 | 2,098,000 | 2,000 | 0.1% |
Note: Figures are rounded to the nearest thousand. Figures may not sum due to rounding. The table shows difference of zero due to rounding.
Chart 3: Number of trips made by unaccompanied trailers travelling from GB to Europe before and after applying revisions, 2020 Q1 to 2023 Q4
7. Country of registration
Note: This section only covers powered heavy goods vehicles. The country of registration is not collected for unaccompanied trailers.
7.1 UK-registered powered vehicles
Table 4 shows the effect of these revisions on the number of trips being made by UK-registered powered vehicles across the period January 2022 to December 2023. The net change over this period was a decrease of 20 thousand trips by UK-registered powered vehicles (3.7%), from 526 thousand trips to 507 thousand. The largest change seen across this period was a decrease of 5.2% in 2023 quarter 2. A reduction from the original figures was seen in all quarters, with each quarter seeing between 2,000 and 3,000 fewer trips.
Table 4: Impact of revisions on the number of trips made by UK-registered powered vehicles, 2022 Q1 to 2023 Q4
| Year and Quarter | Original | Revised | Difference | % change |
|---|---|---|---|---|
| 2022 Q1 | 63,000 | 62,000 | -2,000 | -2.6% |
| 2022 Q2 | 72,000 | 69,000 | -3,000 | -4.3% |
| 2022 Q3 | 68,000 | 66,000 | -2,000 | -3.0% |
| 2022 Q4 | 67,000 | 65,000 | -2,000 | -3.0% |
| 2023 Q1 | 64,000 | 61,000 | -3,000 | -4.7% |
| 2023 Q2 | 65,000 | 62,000 | -3,000 | -5.2% |
| 2023 Q3 | 65,000 | 62,000 | -3,000 | -4.2% |
| 2023 Q4 | 62,000 | 60,000 | -2,000 | -2.7% |
| Total trips | 526,000 | 507,000 | -20,000 | -3.7% |
Chart 4: Number of trips made by UK-registered powered vehicles travelling from GB to Europe before and after applying revisions, 2020 Q1 to 2023 Q4
7.2 Foreign-registered powered vehicles
Table 5 shows the effect of these revisions on the number of trips made by foreign-registered powered vehicles across the period January 2022 to December 2023. The net change over this period was a decrease of 198 thousand trips by foreign-registered powered vehicles (6.7%), from 2.935 million trips to 2.737 million. The largest change between original and revised figures was a decrease of 13.3% in 2022 quarter 4.
For those foreign countries with at least 1,000 vehicle trips from Great Britain to Europe across the period January 2022 to December 2023, the percentage changes were largest for vehicles registered in Hungary (-23%), Latvia (-23%) and Romania (-21%). Previously published annual rankings by country of registration for 2022 and 2023 have been revised, with Polish vehicles remaining the most common. UK vehicles continue to be the second most common, but Romanian vehicles have been replaced by Dutch vehicles following the revisions.
Table 5: Impact of revisions on the number of trips made by foreign-registered powered vehicles, 2022 Q1 to 2023 Q4
| Year and Quarter | Original | Revised | Difference | % change |
|---|---|---|---|---|
| 2022 Q1 | 420,000 | 372,000 | -48,000 | -11.4% |
| 2022 Q2 | 401,000 | 370,000 | -31,000 | -7.8% |
| 2022 Q3 | 368,000 | 338,000 | -30,000 | -8.1% |
| 2022 Q4 | 390,000 | 338,000 | -52,000 | -13.3% |
| 2023 Q1 | 358,000 | 339,000 | -19,000 | -5.4% |
| 2023 Q2 | 357,000 | 331,000 | -25,000 | -7.1% |
| 2023 Q3 | 336,000 | 319,000 | -17,000 | -5.1% |
| 2023 Q4 | 305,000 | 329,000 | 25,000 | 8.1% |
| Total trips | 2,935,000 | 2,737,000 | -198,000 | -6.7% |
Chart 5: Number of trips made by foreign-registered powered vehicles travelling from GB to Europe before and after applying revisions, 2020 Q1 to 2023 Q4
8. Unknown-registered powered vehicles
Note: This section covers powered heavy goods powered heavy goods vehicles with unknown country of registration.
The number of trips completed by vehicles with unknown country of registration increased largely following the revision.
Table 6 shows the effect of these revisions on the total number of trips being made by unknown-registered powered vehicles across the period January 2022 to December 2023. The net change across this period was an increase of 247 thousand trips by unknown-registered powered vehicles (82%), from 301 thousand trips to 548 thousand trips. The largest change between the original and revised figures during this period was a 119% increase in 2022 quarter 1, followed closely by increases of over 90% in several quarters in 2023. This reflects an increase in magnitude in the reporting of unknown-registered powered vehicle trips across all quarters, with each quarter from 2022 quarter 1 to 2023 quarter 4 seeing between 6,000 and 42,000 additional trips.
Table 6: Impact of revisions on the number of trips made by powered vehicles with unknown country of registration, 2022 Q1 to 2023 Q4
| Year and Quarter | Original | Revised | Difference | % change |
|---|---|---|---|---|
| 2022 Q1 | 27,000 | 60,000 | 33,000 | 119.1% |
| 2022 Q2 | 38,000 | 44,000 | 6,000 | 16.4% |
| 2022 Q3 | 38,000 | 58,000 | 20,000 | 52.2% |
| 2022 Q4 | 41,000 | 76,000 | 35,000 | 84.8% |
| 2023 Q1 | 35,000 | 69,000 | 34,000 | 96.6% |
| 2023 Q2 | 42,000 | 80,000 | 39,000 | 92.7% |
| 2023 Q3 | 38,000 | 77,000 | 39,000 | 101.5% |
| 2023 Q4 | 42,000 | 84,000 | 42,000 | 100.2% |
| Total trips | 301,000 | 548,000 | 247,000 | 82.0% |
Chart 6: Number of trips made by powered vehicles with unknown country of registration travelling from GB to Europe before and after applying revisions, 2020 Q1 to 2023 Q4
9. Ongoing quality assurance
Following the investigative work carried out with this data supplier we are now confident that these revisions bring the data for the period January 2022 to December 2023 within the correct RoRo definitions, although due to the retrospective nature of these revisions, the data may be slightly less precise than we would expect for the data that we currently collect. We expect the effect of this uncertainty on published aggregate analysis to be relatively small.
Contact with our other data suppliers has confirmed that correct RoRo definitions are being applied to all other data supplied to DfT. In keeping with DfT’s strategy of producing and maintaining high quality statistics, the RoRo census moved from spreadsheet returns to an online questionnaire in 2023 quarter 4, which has allowed for better quality assurance of data collected.
The Road Freight Statistics Team has also built better relationships with each of our RoRo data suppliers. Regular contact between the DfT team and supplier leads has also allowed for the collection of more business-led intel on changes to ferry routes and other changes, and these open communication channels ensure more proactive quality assurance checks can be conducted.