Greening our Public Transport

Nick Slawicz takes a look at the environmental merits of our two most popular public transport systems.

It has been noted – often jocularly, but never without merit – that if people living in cities at the beginning of the 20th century had been able to foresee how the population would grow over the next hundred years, they would have had two questions about the future of their transport system: where will we get enough horses, and what will we do with all the manure?

Though technology swept in before equine breeders and street cleaners were stretched to their limits, a raft of new questions has emerged. Is public transport sustainable in the 21st century? What can we do about congestion? How can we reduce the impact our public transport systems have on global warming?

Britain is an increasingly urban nation: in 1950 79 percent of people lived in cities; by 2010 over 90 percent do and the figure is projected to grow – albeit slowly – until 2030 at least. Currently 11 cities in the UK have populations of over 300,000. Of these London is the one paving the way to a greener future – and rightly so.

London contains almost 8 million people, and to ensure their transportation needs are met without returning to the “pea souper” fogs of history it has had to develop some novel ideas regarding its public transport systems. The congestion charge and Boris Johnson’s bike rental scheme are widely touted as successes in the capital’s fight to be green, but recent efforts have been focused on shaking up one of the most recognisable elements of the city: the buses.

London’s bus network currently handles some 1.8 billion passenger journeys every year and runs to a fleet of 8,500, of which 100 are diesel-electric hybrids (a figure planned to swell to three times that size by the end of 2012, with eventual plans for all new buses in the city to run on hybrid technology). The city has long had a reputation as a hub of green public transport development, most notably as a result of taking part in a Cleaner Urban Transport for Europe (CUTE) trial from December 2003 to January 2007, and it’s a good thing too: around 20 percent of London’s CO₂ output comes directly from transport, and 5 percent of that comes from buses. It’s less than you’d expect if these journeys were taken by individuals in cars, but still a substantial level of emissions that needs to be brought to account if London has any chance of meeting its goal to lower its carbon emissions by 20 percent by 2020 and 60 percent by 2050.

Thankfully, the city might have a solution. Transport for London has recently unveiled five hydrogen cell electric buses on various routes around the city, and is hoping to add another three by the end of the year. As with any hydrogen cell vehicle, the buses burn clean at the point of consumption (producing only water as a by-product) and are practically silent. Assuming they continue to prove as popular with the public as they seem to have done so far, London might be making strong steps in shaking off its “Big Smoke” image and bringing public transport bang up to date.

Trains on track for a sustainable future

Though buses have a reputation – like most other petrol and diesel-fuelled vehicles – for being smoky and bad for the environment, the country’s railway networks got on to the green bandwagon early, and have stayed there throughout. One of the major selling points about rail travel is its environmental value when compared with flying or driving, with the CO2 level of Virgin’s fleet of electric Pendolino trains estimated to be at least 76 percent less than cars and 78 percent less than domestic flights. Even pure diesel trains are estimated to be massively better for the environment than buses, with an average miles per gallon per passenger rating of 182 compared with buses at 98, according to figures released in 2005 (although both of these figures put short-haul flights to shame, offering as they do only 40mpg per passenger).

Virgin Trains is currently looking at twin-fuel source trains for the future – that is, those capable of running on either electricity or diesel – and while a much-lauded trial scheme in 2007 to run trains on biodiesel wasn’t picked up for application to the whole fleet, other environmentally-useful technologies that were first mass-applied to the railways are now widespread on a variety of other types of transport. The most notable of these is the system’s use of regenerative braking, which returns electricity to the National Grid whenever a driver attempts to slow down, saving enough energy in a year to power almost 12,000 homes.

As urban sprawl and population growth continue onwards, it is always refreshing to find that both industry and local government are finding new ways to deal with common ecological problems while providing valuable public services to the nation as a whole.