Efficiency of transport.

[chriscooper]

I was searching the internet for something, and came across a wikipedia article about tranport fuel efficiency. It gives some figures for the relative efficiency of various transport methods based on MP(US)G per passenger and kJ per tonne KM for freight. It comes from US figures, but I'm sure it applies quite well here aswell. The passenger figures are based on average loadings.

Some of the interesting figures are:
Motorcycle 62MPG/P
Commuter Rail 32MPG/P
Light and Heavy Transit Rail (presume it means Metros, Trams etc) 41MPG/P
Intercity Rail 43MPG/P
Car 33MPG/P
Air 35MPG/P
Transit Buses (presume that refers to in cities) 27MPG/P

Interestingly there isn't a great spread between different types, Motorcycles give the only significant advantage. Also interesting how poorly buses perform, presumably down to poor loadings. Commuter rail suffers due to regular stops, where even regenerative braking only allows around 20% of the energy to be recovered. I expect the general poor performance of public transport in general is down to poor off peak loading, wheras Air will typically run at heavier loadings. I expect figures for the UK would have some difference, due to different loadings and different distances, and generally better public transport use. Lower fuel efficiency of American road vehicles will also come into it. Europe as a whole would also have similar differences, although as far as distance goes should be roughly similar.

Here are the figures for Freight:
Rail 246KJ/T KM
Domestic Waterbourn 370KJ/T KM
Trucks 2426KJ/T KM
Air 6900KJ/T KM

This shows a much greater difference, and a massive advantage to rail, and against air, with only water coming close to rail. I assume again these figures would be roughly the same for the UK or Europe, although again distance would come in with the UK. Loadings should be pretty even.

The interesting thing from this is that it seems Freight is where Rail really has a major advantage, and where air really is terrible. This does lead to the question of whether more investment needs to be put into rail freight, and particularly whether freight should be disadvantaged compared to passenger, something that can easily happen with increasing speeds on the Intercity network, conjestion on the commuter network, and attempts to reduce costs on the rural network (light rail style methods). Whilst in the UK we always go on about how passenger speeds havn't improved much over the years, beyond the big improvements in the 60s and 70s (when unfitted, 4 wheel wagons were replaced with braked bogie wagons) there has been no real increase in freight speed. If anything, the continent is worse, with passenger trains flying along purpose built high speed lines, whilst freight still crawls around the often poor "classic" network. One thing I'd really like to see is moves towards high speed containerised freight. The coming replacement of the first generation HSTs (talking in a general sence, rarther than purely the BR one) is a perfect oppertunity to convert some to high speed freight use. Even 125mph would give a big advantage, when freight rarely exceeds 75mph anywhere in the world, let alone 186mph. IMHO, any new high speed lines in the UK should be built with high speed (100mph+) freight in mind aswell as passengers.

Just one other interesting figure. Cycling is not only a highly efficient mode of transport, giving equavalent of 653MPG, it's even considerably better than walking, which manages just 235MPG (it's interesting that at it's best, powered transport can be in the same level of efficiency as walking).

[mattvince]

I'd be interested to know what they define as 'commuter rail' - in the US, this tends to translate into EMD F59PHIs hauling half-a-dozen Bilevel coaches, which, whilst efficient in themselves, are still very heavy trains - and don't have regenerative braking. As you mention, the efficiency of a train is wholly down to loadings - which vary considerably according to time-of-day, and can vary even between nations/regions - the aforementioned F59PHI outside the peak, as compared with some of the Japanese peak-time operations (to say nothing of the Mumbai network at rush-hour). Using miles-per-gallon is probably a misleading calculation: it depends on the energy density of the fuel used (which is different for petrol (Gasoline), road diesel, rail diesel and aviation kerosene) coupled with the energy efficiency of the engine and drivetrain. And how do you measure Uranium in gallons - or photons of light for that matter? Whilst the authors of the piece will have done some conversion work, how do you make a meaningful comparison between two modes which use dramatically different forms of power - and more to the point, how do policy-makers draw meaningful conclusions when faced with that problem?

Off-Peak loadings will always be the problem with public transport's fuel efficiency: operators can run less capacity (shorter trains, smaller buses) at lower frequencies, but then that leaves other problems such as 'mini-peaks' (after 09.30, late evenings, special events), some of which are not entirely predictable (for instance, how would a bus operator know up to a week in advance that the weather on one day will be so good that all the Pensioners in the county will decide to go to the seaside that day? Not even are the Met Office that good!). Then there are contra-peak workings (running nearly empty high-capacity trains/buses in the opposite direction to the peak to enable a second peak-time/peak-direction service to use those vehicles). Also, off-peak frequencies are, certainly as far as UK rail is concerned, contractually required to operate, irrespective of whether they carry one person or one hundred - which is an interesting argument for road-to-rail modal shift: car journeys are optional, railway services (and many bus services) are mandatory.

Of course, fuel efficiency is but one factor amongst many in the whole Geo-Techno-Enviro-Political problem of how we wish to power the nation, and the world come to that. And that is a much bigger problem than something as simplistic as a mode-by-mode fuel efficiency comparison can possibly answer.

As to railfreight - the sad reality is that most transport companies in the UK have invested so much in road haulage that they cannot possibly go back - look at the siting of distribution centres for chain retailers. That a 70s-style fuel crisis would bring their transport network to its knees is probably not in their thinking. But it still raises the question of why, when most freight transport in the UK is of the distribution type, does the railway not try to get a real foothold in that market? Yes, there are a few services, but minuscule compared to the road dominance of the market. And what of short-length freight trains: why not the application of proper multiple-unit principles to freight - with the ability to attach and detach portions, then a series of inter-connecting services could operate at minimal operational cost covering much of the nation. And, of course, none of the problems of passengers getting in the wrong portion, as cargoes would be matched with the relevant wagon in the relevant portion, pre-reserved using similar yield-management techniques to that used for advance fares on the passenger railway (that has been around for years, both in trucking and by North American railroads). Portion working could be done by loco-haulage, provided the yard infrastructure is in place, plus the costs of trip working can be reduced.