Number Crunching in Transport

Wednesday, February 3, 2010


Sudhir Gota

Latest news from Mumbai got many people excited about Monorails and its impact on emissions. The news report claimed that on an average the mono rail would save 3500 tons/year/km. This kick started a debate on emissions savings from metro rail projects and its hidden component – construction emissions. The debate pitchforked the main issue of infrastructure construction as a significant component of transport emissions. Experts believe that we do a great disservice to entire emissions argument from transport by not considering such hidden aspects and we need to consider whole emissions argument from transport with a pinch of salt. Researchers like Mikhail Chester have proved that Construction is significant component of total life cycle and should not be neglected.

Gigantic infrastructure projects take ages to plan, get approved, and finally to get implemented in a developing country. Bangalore metro substantiates the above statement. Mass rapid system in Bangalore have been studied from past late 1980’s and it was only until in early 2000’s that some actual planning was initiated. Main construction for approx 40 km of metro was initiated in 2006 and the people would only get a chance to experience the system in the year 2012. By the time metro starts chugging along the Bangalore streets, things would have changed. This argument is in fact more worrisome for elevated roads and isolated flyovers which take two years as an approximate to complete in a city like Bangalore. While the traffic suffers, emission gets multiplied and finally it opens to jam-packed traffic created by land use manipulations by builders anticipating zero congestion.

Massive projects require huge quantities of material, machinery and workers which create many leakages in emission profile. Research coming out from Japan reinforces this argument that expensive metro can in fact accumulate high intensity of emissions during construction. Researchers from Nagoya university have estimated that a station of the Superconducting MAGLEV generates emissions of magnitude 2,430[t-C/station] during construction only. Many researchers in order to to simply the calculations argue that only the emissions generated during material production be considered as a basis. But then, research also suggests that material movement, use, disposal can accrue 42% of production emissions.

The above argument looks minute in nature if we consider emissions quantified from Cairo Subway which shows that construction emissions are equivalent to 28 years of operation emissions !!

This above arguments raises an important related question –

would High speed rails really save emissions?

There has been tremendous push for such massive projects in developing countries in the name of climate change. Do we really need such expensive solutions to “reduce” emissions? Literature suggests that high speed rails emit approx 73 grams/passengerkm during operations. Indian railways preliminary estimates suggest that a High-Speed Rail consumes 0.933 litres of fuel per 100 km travelled, in comparison to the 4.04 litres consumed by an airplane and 5.69 litres consumed by an economy car. But, what remains hidden in the entire argument is fact about construction emission. Experts have suggested that high-speed rail can produce some 10 million metric tons of CO2 per year during construction.

Back of the envelope calculations suggest that a kilometer of high speed rail would cost anything from 10-20 million $/km in developing countries when neglecting land costs. Even if we blindly assume that emissions are being saved by such corridors, can developing countries really afford it?

We need more debate and need to see more numbers as massive construction can really change the game!!

1 comment:

Post a Comment

Total Pageviews