Train vs driving

Fuel only or the full cost of the car

From 6 April 2026 HMRC’s approved mileage rate for cars is 55p a mile for the first 10,000 business miles in a tax year and 25p after that. It was 45p from 2011 to 2026. The rate covers fuel, tax, insurance, servicing, repairs and depreciation, so it is close to the full cost of a car you only keep for the trip. HMRC’s advisory fuel rates from 1 September 2026, which cover fuel only, run from 14p to 27p a mile for petrol cars depending on engine size. If you would own the car anyway, the true extra cost of a commute sits between the two: the fuel plus some extra wear. If the commute is the main reason you run a car, or a second car, the 55p figure is nearer the truth.

Turning a season ticket into a price per trip

Divide the ticket by the one-way journeys you will actually make. An annual season ticket is usually priced at about 40 weeks of weekly tickets, so it pays off only if you travel most weeks. If you go in two or three days a week, a Flexi Season gives any 8 days of travel in 28 and National Rail says it offers at least a 20% discount on an equivalent monthly season ticket. Regulated fares in England, which include Standard class season tickets, Anytime and Off-Peak tickets, were frozen in March 2026 until March 2027. Advance tickets, First Class and some operators are not covered by the freeze.

Door to door, not timetable to timetable

A 50-minute drive and a 55-minute train can swap places once you count the walk to the station, the wait on the platform and the walk at the other end. Time spent finding a parking space belongs in the driving minutes. In the Department for Transport’s National Travel Survey for 2025, the average commuting trip in England took 31.5 minutes including waiting, and covered 9.2 miles. Full-time workers who commuted by rail travelled about 24 miles a trip, against about 11 miles for those who drove, which is why the train tends to be used for long trips into cities and the car for shorter ones.

Sharing the car and paying to park

Two people sharing a car halve the cost each, while the train fare stays per person. In practice few commuters share: the National Travel Survey found 89% of car commuting trips in 2025 were made by a driver on their own, and the average car on a commute carried 1.13 people. Parking can decide the result on its own. Driving into central London on a weekday means the £18 daily congestion charge, before any parking fee. Delays, cancellations and fuel price swings are not modelled; if reliability is the reason you choose, add a typical buffer to the time sliders.

Worked example: Milton Keynes to London on a season ticket

This turns a real season ticket into a price per trip, then works out how far you could drive for the same money.

1. An annual Standard season ticket from Milton Keynes Central to London Euston costs £6,836. That price was set in 2025 and held by the 2026 fares freeze.
2. Travelling in five days a week for 46 weeks is 460 one-way trips, so the annual ticket works out at £14.86 a trip.
3. Twelve monthly tickets at £656.30 would cost £7,875.60, so the annual ticket saves £1,039.60 if you would otherwise buy every month. A weekly ticket at £170.90 is £17.09 a trip over 10 trips.
4. Fuel cost per mile for a petrol car: 175.28p a litre (the UK average for the week of 12 October 2026) × 4.546 litres in a gallon ÷ 42.8 miles per gallon = 18.6p a mile.
5. £14.86 ÷ 18.6p is about 80 miles. £14.86 ÷ 55p is about 27 miles.

On fuel alone, a car beats this season ticket on cost for any drive under about 80 miles each way. At HMRC’s full 55p rate it only wins under about 27 miles. Driving into central London also means the £18 congestion charge, which adds £9 to each one-way trip, before parking.

What people get wrong

“I can claim tax relief on the miles I drive to work.”

Not for a normal commute. HMRC’s mileage tax relief does not cover travel between home and your regular workplace, only business journeys and trips to a temporary place of work.

“HMRC’s mileage rate is 45p a mile.”

It was, from 2011 to 2026. For the 2026 to 2027 tax year it is 55p a mile for the first 10,000 business miles and 25p a mile after that.

“Comparing the train fare with petrol money is a fair test.”

Fuel is only part of the cost. On a 30-mile trip, fuel at 18.6p a mile is £5.58, while the 55p rate is £16.50. Which figure is fair depends on whether you would keep the car without the commute.

“A railcard will cut the cost of my season ticket.”

Most railcards cannot be used on season tickets or Flexi Season tickets. The exceptions on Flexi Season are the 16-17 Saver and the Jobcentre Plus Travel Discount Card, which give 50% off.

“Train fares always rise every March while driving costs stay flat.”

In 2026 it went the other way. Regulated fares in England were frozen in March 2026, and the Office of Rail and Road found fares across Great Britain unchanged on average while RPI rose 4.1%. Meanwhile the UK average price of petrol rose from 134.81p a litre in the week of 13 October 2025 to 175.28p in the week of 12 October 2026, and diesel from 142.99p to 200.04p.

Common questions

How we calculated this

Driving cost per person = (distance × cost per mile × trips × weeks + parking per day × days in the workplace × weeks) ÷ people sharing the car, where days in the workplace = trips per week ÷ 2. Train cost = ticket × trips × weeks. Driving time = drive minutes × trips × weeks; likewise for the train, then convert to hours. Difference = driving − train for money and for time. Break-even cost per mile = the driving cost per mile at which both options cost the same. Distance is miles one way per trip, matching a ticketed one-way leg; count a return as two trips. This experiment provides estimates for educational purposes and is not financial advice. Actual results vary depending on rates, fees, taxes, inflation and individual circumstances.

Assumptions and limitations

Sources

• HMRC: Travel mileage and fuel rates and allowances

  Approved mileage rates for cars: 55p for the first 10,000 business miles from the 2026 to 2027 tax year (45p from 2011 to 2026), then 25p.

• HMRC: Advisory fuel rates

  Fuel-only rates per mile from 1 September 2026: 14p to 27p for petrol and 15p to 22p for diesel, by engine size, with the mean mpg figures used here.

• Department for Energy Security and Net Zero: Weekly road fuel prices

  UK average pump prices: petrol 175.28p and diesel 200.04p a litre for the week of 12 October 2026, against 134.81p and 142.99p a year earlier.

• GOV.UK: Tax relief for vehicles you use for work

  Mileage tax relief does not cover travel to and from your regular workplace.

• Department for Transport: National Travel Survey 2025

  Average commuting trip of 31.5 minutes and 9.2 miles in England (table NTS0403); rail and car commute distances for full-time workers (NTS0412); 1.13 people per commuting car and 89% lone drivers (NTS0905).

• Office of Rail and Road: Rail fares index 2026

  Fares across Great Britain unchanged on average in 2026, against a 4.1% rise in RPI; regulated fares down 0.1%.

• Department for Transport: Rail fare freeze starts (2 March 2026)

  Regulated fares in England, including season tickets, frozen from March 2026.

• National Rail: Flexi Season tickets

  Any 8 days of travel in 28, with at least a 20% discount on an equivalent monthly season ticket; most railcards not accepted.

• London Northwestern Railway: Commuter travel guide

  Milton Keynes Central to London Euston season tickets: weekly £170.90, monthly £656.30, annual £6,836.

• Transport for London: Congestion Charge

  £18 a day if paid on the day or in advance.

• National Rail

  Timetables and fares for Great Britain’s railway; use a real quote in the ticket slider.

All IfSketch sources · Methodology