Energy and carbon savings with trams – a short paper by Professsor Lewis Lesley

“Getting urban car trips down from 70% to 50% would save about 5% of UK carbon emissions.”

 

Transport is an energy intensive activity, heavily dependent on oil (99.97%) and a significant emitter of carbon dioxide (30% of UK total). Exhortation and education can reduce car dependency but in the absence of draconian powers to force people to change travel modes, people will freely choosing sustainable alternatives is surely the best way?  Market research and behavioural studies demonstrate that for short journeys, under 2 miles (50% UK car trips) walking and cycling are acceptable options, when there are safe and attractive routes. For longer urban journeys ( < 5 miles = 75% of UK car trips) public transport should be the alternative to car ? In the UK most urban public transport is by bus (80% of trips).  Car users however are not willing to use buses. Studies by the US Transportation Research Board shows that on a like for like basis of frequency, travel speed, fares etc, buses attract 40% less car users than even old rail services.

 

Getting car people to use public transport means rail services. Metros and railways would be ideal but most UK towns and cities do not have suitable lines and constructing new lines needs a lot of embedded energy and is very expensive , eg. the proposed London 6 miles long Crossrail will cost £12bn. A former Secretary General of the International Public Transport Association (UITP) observed that light rail gives 90% of the benefits of a metro at 10% of the cost. The speed at which new tram systems have been opened in the UK over the last 20 years, one every 4 years, means that it will take 150years  to catch up with Germany. Promoting and funding new tramways is the subject of another paper but given the public funding available, it would probably be better spent promoting cycling and providing cycle networks, and raising the modal split from 2% to 10%, as has been done in Denmark and Germany.

 

Compared to buses, tram operating along the same route, at the same maximum speed carrying the same passenger loadings will use less than 25% of the energy, which will be electricity, not oil. Indeed I am working on several projects where new tramways will be powered by renewable generation, therefore in energy terms totally sustainable, and almost carbon emissions free, once the embedded energy to build the trams and track have been depreciated, usually a couple of years of operation. Indeed bus operators with routes having a peak frequency of ten buses or more per hour, could already make financial savings in converting to trams. This excludes any carbon emission considerations, and if the new tram service only carried former bus passengers there would only be the energy ( and carbon) savings of trams compared to buses. The real carbon savings come from diverting urban car trips.

 

New tram systems in France, have attracted 30% more patronage (all car diverted) than the bus services replaced. This is in line with the earlier US study. Car travel is energy intensive, and for short urban trips highly polluting. By suitable park and ride, as well as walk and ride, about 50% of car trips in the tram corridor will be attracted. Getting urban car trips down from 70% to 50% would save about 5% of UK carbon emissions.

2 comments on “Energy and carbon savings with trams – a short paper by Professsor Lewis Lesley

  1. I fully support the comments made by Professor Lesley.

    However, there circumstances where the extra cost of OHL equipment means that trams will not be considered.

    Other reasons include the development of tram systems in locations subject to Hurricane or Cyclone activity where the ability to restart service as soon as the track is confirmed clear makes an undeniable case for trams powered by on board energy source with some form of energy storage.

    Powered by locally produced energy such as biogas from waste allows trams to have a wider impact on Global Emissions and Energy savings.

    Combining both systems could allow some 200 towns and cities in the UK alone to developed a tram based transport network.

    Added incentives include the use of the tram system to collect rubbish for recycling or deliver goods.

    The “as is” faction just have not grasped that we can not replace oil with bio fuels or an other energy supply presently.

    The final question is do we want to continue to mould our lives in order to accommodate a 1.5m x 2m box (the car)or shall we give our towns back to the people.

  2. A quick comment on this:
    “Market research and behavioural studies demonstrate that for short journeys, under 2 miles (50% UK car trips) walking and cycling are acceptable options, when there are safe and attractive routes. For longer urban journeys ( < 5 miles = 75% of UK car trips) public transport should be the alternative to car ?”

    I’d like to note that neither trip origins nor trip destinations are fixed. People move home, change job, choose to shop at different places, make friends in different neighbourhoods, and so on. Therefore, (particularly during times of economic growth), trip lengths are as changeable and as subject to influence as modal choice is.

    With that in mind, then the scope for the substitution of car trips with walking & cycling is much higher. After all, the past 30 years have seen the reverse of that – instead of walking to the local shops, people now drive to the out-of-town supermarket. So the local shops closed. If people start shopping locally at what shops remain, then new local shops will come, and a weekly 5-mile shopping trip by car will be replaced by 3 or 4 walking trips to the local shops per week.

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