Planes Trains & Automobiles

Whilst answering a question on Yahoo Answers today I thought about what form of transport is more efficient Planes, Trains or Cars, you may think it is quite obvious but due to the huge variation in efficiencies in each you may be surprised that some methods are not as efficient as others.

Q. How many people need to be on a train to make it more efficient than them driving in seperate cars?
How many people would need to be on a train (including the driver if you like) to make it more efficient in terms of carbon emmisions than them driving in seperate cars over an arbitary length of say one or two hundred miles?

A. Using information from marketing material from Virgin Trains for its Class 390 Virgin Pendolino trains. I am using the data from a 296.5km from London Euston to Manchester Piccadilly. A car would emit 27.45kg (to get exact data for your car you should visit VCA Car Fuel this calculation would be based on a small car with engine under 1.4lt) of carbon dioxide. A Class 390 Virgin Pendolino train would emit 1806kg of Co2 for the same journey. With 439 seats, with an average fill capacity of 51% or 224 people. The train emissions should equal approximately 66 cars. So for each passenger driving in separate cars this would be 66. However the average for each car journey is 1.56 passengers, so the Virgin Pendolino would need to have a minimum of 103 passengers to ensure that it was more efficient than the equivalent cars. The only figure I could find for bus emissions was 23g/ppkm when a bus was full (from the Department for Transport Canada). Thus this would equate to 375kg of Co2 for a 55 seater bus. But on average each bus has 16 persons per km. The bus emissions should equal approximately 14 cars. So for each passenger driving in separate cars this would be 14. Using the average for each car journey as 1.56 passengers, the bus would need to have a minimum of 22 passengers to ensure that it was more efficient than the equivalent cars.

Using Department for Environment, Food and Rural Affairs (DEFRA) figures from 2005, to fly the journey would take approximately 42.5kg, (however this figure is only the average per passenger, no exact figures are available).

So overall using the figures that are available, it would appear that the most efficient mode of transport is the train, followed by the car, bus and plane. However, as I did say this is only how it appears; should you be travelling in a low emission car with 4 passengers this would be more efficient than that of the train.

For the individual its a difficult choice on which method to take as in most cases there are so many factors which effect the eventual outcome of Co2 emissions. But public transport will always operate, even if there are no people to use them, therefore if we all shifted our use from the car to public transport not only would it become more efficient, it would also become cheaper too.

In the coming weeks I will compare the UK's poor record on public transport use to that of Hong Kong, which offers one of the worlds most efficient public transport networks.


Notes: These figures only take into account the direct emissions from fuel consumption. There will be indirect Co2 emissions in developing the vehicle and its infrastructure which are not included. The car used in this assumption is a small car with an engine size of 1.4lit or smaller. Less efficient cars would make the bus and train more efficient, and less efficient buses and trains would make the car more efficient in the comparisons.


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