I am a keen defender of fresh air, a regulator of chimneys, a controller of exhausts, someone who wishes to defend beautiful countryside and great heritage buildings. I dislike fumes, noise and other environmental nuisances. These days being green seems to mean to some just one thing- cutting carbon dioxide emissions. I am quite happy to do that, where it means more fuel effiency, less waste and better methods of making things, heating and travelling.
There is a general view that railways are green whilst all other modes of engine powered travel are not. This is a strange view. Trains need diesel or electric engines to pull them, which in their turn generate emissions including CO2. If we wish to see how much more efficient railways are than cars, buses, coaches, ships, planes and other powered transport, we need to do a proper audit. The figures which result show it all depends. It all depends how the electricity was generated and hwo the double inefficiency of the power station and the electric engine works out. It all depends how new or old the train is, how efficient it is and how many people are on it.
The figures are mainly sensitive to capacity utilisation.Crowded buses and trains do emit less CO2 per passenger mile than single occupant cars or vans. By the same kind of measure fully packed container ships can be more efficient than container trains.
However, in the real world we need to compare journey with journey, looking at the total journey, not just the part of it conducted by train. In practise many train journeys are part of a mixed mode journey. People drive to the station, or go by taxi or bus. They often use other powered transport at the other end. Containers are often taken to the railhead by truck, and may be shifted from the end of the train journey by truck or ship.
When you start to look at actual journeys as opposed to station to station journeys the audit becomes more complex and less favourable to the train. If you factor in poor capacity utilisation in the off peaks that too can reduce or eliminate the lead of the train on emissions per mile travelled.
Maybe we should also factor in the impact of one mode of travel on another. One of the main causes of congestion in the typical town or city in the UK is the shortage of places to cross the railway. This can be exacerbated when the crossing is provided by means of a level crossing rather than a bridge or tunnel.
In Wokingham we have three level crossings to let traffic across the two railway lines serving the town. Under new plans for more train services the level crossing at the station could be blocking cars for 34 minutes in every hour. This will create substantial jams around the town, and in the off peak periods will mean a lightly used train could be holding up many more people in cars.
Click on link to read John Redwood's article
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