Not really, rail is still more carbon efficient that buses in this country, on account of average loads and overall efficiency. The figures from transport direct take overall average loads, which is 33% for rail.
The average load for a train is 108 people and bus 9 (source ATOC/Dft). That said, if you had a 60% load on a class 166 you would get roughly 493 passenger miles per gallon compared to 360 on a Volvo coach. Fully loaded a modern MU is still better than a bus. Figures taken from the department for transport.
Rail magazine recently published a graph showing megabus a little bit more efficient than an IC255. But they didn't publish the small print which showed the megabus load was 60% and the train load was 32%. I've seen the original work done by RSSB etc In actual fact loads on the ECML are around 60% now overall, thanks to yield management.
The fact remains is rail journeys are typically 2-3 times faster than buses, talking the elasticity of demand and supply into account, generally it is much harder to attract people out of their cars or even induce any sort of demand with the much slower bus services run in the same way.
National express have had some success with yield management with higher overall loads than compared to commuter rail services, and thereby being more carbon efficient. But this is to be taken in context, because a like-for-like replacement where there is low off-peak use, would result in carbon figures even worse.
For the latest rail emissions statement it is worth consulting the latest ATOC documents:
http://www.atoc-comms.org/admin/userfiles/Energy & Emissions Statement - web version.pdf
which gives passenger diesel rail at 69 g Co2/pkm
electric rail at 51g Co2/pkm
and overall 58g Co2/pkm
also with the caveat of
'These emissions figures are based on the average UK electricity generation mix. The actual
picture for electric rail is very much better than the table above would suggest since
operators source electricity from British Energy whose carbon intensity of supply is much
lower than that of the average generation mix – around 100gCO2/kWh, about a fifth of
the UK average – largely due to the high proportion of nuclear generation (approximately
87%) in the total.'
So on an accounting basis, electric rail is nearer 10g Co2/pkm, this compares to figures from Defra which show buses at 89g co2/pkm
Interestingly, since 1996 rail has cut emissions per pass km by 25%, cars by 9% and domestic air has *increased* by 11%. Despite the claims of many commentators.
So the answer is, if you want 1/2 - 1/3rd of the journey time and attract people out of their cars and to cut carbon is to support the train service. Indeed, if you really want to cut carbon, electrify it and power it by Nuclear. Rail generally also opens up opportunities for rail freight which is 4-10 times better than road in terms of emissions.
