From scanners at supermarket tills to ticket offices at railway stations, new data on everyday costs are improving our understanding of how prices are changing over time.

It is crucial to measure price changes as precisely as possible, because accurate measures of inflation are playing an increasingly vital role in business, government, and everyday life.

We are working with several new data sources to produce improved and more detailed inflation data. These include:

  • Transactional data on rail fares from Rail Delivery Group.

  • Web-provided data on second-hand cars from Auto Trader

  • Microdata level rental data

  • Grocery retail scanner data

Data from these sources (including 40 million monthly rail fares transactions from Rail Delivery Group and 300,000 monthly second-hand car sales from Auto Trader) have already improved our Consumer price statistics.

We have been working with several grocery retailers to gather scanner data, covering approximately 50% of the UK grocery market share. We hope to introduce this to our Consumer price statistics from March 2025.

Meanwhile, our transformed private rental data provide greater detail in rental statistics and are more responsive to market changes.

As well as providing information on prices, these alternative data sources contain a wealth of other insights, including expenditure data.

Rail ticket sales drop during strikes and storms

We now have access to millions of rail fare transactions in Great Britain dating back to January 2019, from the rail industry’s Rail Delivery Group. Before March 2023 we collected one data point per year, while we now use around 40 million per month (in a typical year).

From these daily transactions we can see the effect of major events on the number of rail tickets sold.

Bad weather and strikes can affect the number of train tickets bought

Date of travel, number of daily rail fare tickets, Great Britain, January 2020 to June 2024

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Download the data for numbers of daily train tickets sold [XLSX, 63KB]

The number of daily tickets sold was far lower during the period of restricted movement during the coronavirus (COVID-19) pandemic, as well as on Christmas Day.

Strikes or extreme weather also affected the number of train tickets sold.

On Thursday, 20 July and Saturday, 22 July 2023, the Associated Society of Locomotive Engineers and Firemen and National Union of Rail (ASLEF) and Maritime and Transport Workers (RMT) unions were on strike. This resulted in a drop of tickets sold on these days by 50% and 44% compared with the same days the week before.

On the day of Storm Eunice, Friday, 18 February, 2022, there was a 54% fall in the number of train tickets sold, from 1,576,215 on the same day the week before to 720,070.

These data are extremely detailed, including information on where people travel from and to, ticket class, ticket type and price. Using destination stations, we can see the impact large events have on passenger numbers at nearby stations.

In the week of Glastonbury Festival in 2023, ticket sales shot up at Castle Cary, the nearest station to the event. In the week of 18 June 2023, there was a 663% increase in tickets sold, when compared with the average sold across 2023 excluding Glastonbury Festival.

The nearest station to Glastonbury festival saw a 654% increase in tickets sold in the week of Glastonbury 2023

Percentage change of weekly rail fare tickets where the destination station was Castle Cary, Edinburgh Waverley or Abergavenny, compared to the median over the year for each station, Great Britain, January 2023 to December 2023

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Notes:
  1. Data is grouped by week with the week beginning Sunday.

  2. The median over the year for each station includes the value from the week of the biggest event.

Download the data for train tickets sold during UK festivals [XLSX, 21KB]

The effect of Glastonbury Festival on local rail sales was far larger compared with ticket sales data from stations near other festivals.

At Edinburgh Waverley Station, ticket sales increased by 71% in the week of 6 August 2023, the first full week of the Edinburgh Fringe Festival.

Meanwhile, at Abergavenny, the closest railway station to the Green Man Festival, ticket sales increased by 104% on average in the week of 13 August 2023.

Sales of second-hand hybrid cars are on the rise

Second-hand sales data from Auto Trader provide information on an estimated 300,000 used car sales per month, dating back to 2018.

We use this to produce our petrol and diesel second-hand car inflation indices. As well as the advertised price, they include information on vehicle manufacturer, colour and fuel type.

We estimate that the number of second-hand hybrid cars sold increased by 59% from 2022 to 2023.

The additional detail in this data helps us assess how representative the consumer price basket is of the wider market. The “shopping basket” of items used to measure consumer price inflation changes each year to reflect consumer spending patterns.

While the price of new hybrid and electric vehicles are included in the consumer price basket, second-hand sales of these cars are not captured because of the relatively low amount of money currently spent on them.

Most hybrid and electric cars in the UK are bought new, meaning there are relatively low numbers of second-hand sales, but these new data allow us to monitor trends and update our representative basket when spending hits the necessary threshold.

As the data are received daily, and a vehicle is listed for an average of 40 days before being sold, this still leaves multiple listings for each unique vehicle within the dataset.

To estimate the number of individual cars we use a four-day gap before considering a listing "sold" to produce our index. For more information see our Using Auto Trader car listings data to transform consumer price statistics, UK release.

As these data are for advertised listings, they do not contain explicit sales revenue information.

Petrol is still the most common fuel type among estimated second-hand sales

Estimated proportion of second-hand cars sold by fuel type, UK, June 2021 to June 2024

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Notes:
  1. Excludes electric vehicles.

Download the data for the proportion of petrol, diesel and hybrid car sales [XLSX, 17KB]

Meanwhile, black, grey and white were the most popular colours of second-hand cars sold in 2023.

Other than grey scale colours, the most popular second hand cars of 2023 were blue, silver and red

Estimated percentage and number of second-hand cars sold, broken down by colour, UK, January 2023 to December 2023

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Notes:
  1. Other in the second visualisation includes maroon, burgundy, magenta, navy and indigo.

Download the data for used car sales by colour [XLSX, 19KB]

Some of the least popular colours were pink and turquoise, with 3,000 of each estimated to be sold in 2023.

Beige, a colour often seen as being plain, was not popular among drivers, with an estimated 12,000 cars sold in that shade in 2023. More drivers were willing to be bold, with approximately 19,000 opting for a multicoloured car.

Gold may normally be linked with victory, but compared with the other medal colours, silver and bronze, it takes third place. Approximately 385,000 silver cars and 11,000 bronze cars were estimated to be sold, compared with 5,000 in gold.

And finally, in the battle of red versus blue, blue is the clear favourite among second-hand car drivers, with around 554,000 drivers choosing blue vehicles, compared with 362,000 choosing red.

‘Newer’ is not always better when buying a second-hand car

The biggest appeal when buying a second-hand car is usually the cost. They are typically cheaper than a new model, but the trade-off is that the older a car gets, the more likely it is to have problems later on.

Second-hand cars aged two to four years were most popular among UK drivers in 2023

Estimated number of second-hand cars sold, broken down by age in years, UK, January 2023 to December 2023

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Download the data for second-hand car sales by age [XLSX, 16KB]

The sweet spot, according to the public, is two to four years old. In 2023, an estimated 905,000 cars were sold in that age bracket, making it the most popular age for second-hand cars.

The ‘newest’ second-hand cars were not amongst the most popular. An estimated 391,000 cars two years or younger were sold last year.

While newer cars are generally associated with greater quality, there are some exceptions to that rule. According to Auto Trader, approximately 23,000 cars that were aged 18 years or over were sold in 2023, showing that when properly looked after, a car can have a very long life.

However, a car that has clocked up a high mileage is less appealing to buyers, with data showing a low mileage is more important than a short lifespan.

An estimated 1.8 million second-hand cars sold had 40,000 miles or fewer on the clock, in 2023.

As with older cars, some drivers were able to find value in cars with very high mileage. Approximately 31,000 cars with over 140,000 miles on the clock were sold in 2023.

Auto Trader's new data also allows us to see how many cars were sold by each manufacturer. By grouping these car brands by nationality, we can see which countries are the most popular producers of second-hand cars in the UK.

German manufacturers made the most popular second-hand cars in 2023

Estimated number of second-hand cars sold, broken down by manufacturer countries, UK, January 2023 to December 2023

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Notes:
  1. Countries with two or fewer car manufacturers have been grouped into 'Other'

Download the data for second-hand car sales by manufacturer's nationality [XLSX, 16KB]

German cars were the most popular second-hand vehicles sold in 2023, with an estimated 1.1 million purchased.

Rounding out the top five were British cars (estimated 569,000 sold), Japanese cars (estimated 535,000 sold), USA (estimated 400,000 sold) and France (estimated 316,000 sold).

Making future improvements to our price statistics

It is crucial for us to be able to continue improving our statistics, and using more detailed and accurate data helps us to achieve that.

We plan to update our headline statistics to include grocery scanner data in March 2025, allowing us to measure changes in food and drink prices more effectively.

As we continue to work with new, more robust data sources, we will be able to keep improving our statistics and find exciting ways to explore new trends.

For more information please see our Transformation of consumer price statistics release.

Read more about our consumer price statistics.

Contact

Consumer Prices Inflation team
cpi@ons.gov.uk
Ffôn: +44 1633 456900