The Crossrail project started in
2012 and is currently the largest infrastructure project in Europe. As of
today, it is 80% complete and should be finished and entirely running by 2020.
But one might wonder whether this project truly is beneficial.
This assignment will focus on the
environmental impact of the project and compare the effect the technology used
in the Crossrail project to the one of the original tube lines. The CO2
emission will be used to measure the environmental repercussions of the Crossrail
To facilitate this study, some simplifications
will be made. Firstly, I will use an average CO2 emission and train
frequency for the entire pre-existing underground system, without
differentiating the different lines or time of the day, which will help make
the comparison easier. I will also assume that the average train frequency on
the Elizabeth line is the same as on the underground lines. Secondly, I will
use the maximum capacity of the train to measure the maximal beneficial impact
of the Crossrail.
To compare the environmental impact
of the Crossrail technology and the underground technology, I will first
compare the annual CO2 emission of the trains for the same distance.
To have a better understanding of the actual benefit, it is also interesting to
look at the capacity of the trains in term of travellers.
‘Based on the current RIBA E designs,
Crossrail is expected to emit between 9.6 million tonnes and 14.9 million
tonnes of CO2 during its lifetime (construction and 120 years of operation).
Most of these emissions (85%) will be from operation, as opposed to
construction.’ (Crossrail Ltd., 2011: p-1).
In order to obtain the CO2 emissions of the Crossrail during its
lifetime, I’ll use the arithmetic means. Indeed, even though the values are
from different magnitudes, they remain relatively close. The main focus being
the emissions from operation, the value we need is only 85% of the total C02
emissions of the project. Let’s call Etotal the CO2 emissions during
the Crossrail’s lifetime, excluding construction, and E the emission over one
Etotal=(9.6+14.9)/2=12.25*0.85=10.41 million tonnes.
That value can be rounded to 10.5 million tonnes.
To do the comparison, I will use the value of carbon emission over one
E=10.5/120=0.09 million tonnes per year, so about 90 000 tonnes per
emissions for TfL and its business units (TfL, 2014: p-29)
The London underground produced about 550,000 tonnes of CO2
in the year 2013/2014.
We know that the Crossrail covers a total length of approximately 100km (Crossrail
Ltd., 2018a), and that the original tube rail length is of 402km (Transport for
London, 2018a). As I assumed that the CO2 emission was evenly spread
across the lines, meaning that no portion of the rail is more CO2
producing than others, the equivalent consumption of the Crossrail would have
been 118/402 times the consumption of the tube if it had been created with the
So, the Crossrail technology consumes roughly 66% as much as the
This is true if I consider the number trains, and logically, should
prove true when considering the number of users.
Let’s assume that the waiting time is the same for both the Crossrail
and the underground. Using geometric means, I can set the lower bound to 1
minute, and the upper bound to about half an hour. The average waiting time is minutes.
This means that there is a frequency of about 11 trains per hour on average. As
the functioning times of the Crossrail have not been made available yet, I will
compare the train capacity per hour.
The maximum capacity of the Crossrail trains is 1,500 persons (Crossrail
ltd, 2018b), so 16,500 persons per hour. The average capacity of underground
trains is: persons
per train (Transport for London, 2018b), so about 9,150 persons per hour. This
means that the Crossrail can transport times
more people in the same amount of time.
Not only is the Crossrail much less polluting, it is a much more
efficient transport method when considering the number of people travelling. Many
details were left out of this study. Indeed, it can be argued that many underground
users will not use the Crossrail and that the capacity comparison cannot realistically
represent the effect that the Elizabeth line will have once it starts. The
study also considered the underground and Crossrail users as a closed system
and did not take into consideration the possible displacement of car journeys.
Lastly, the CO2 emissions of the construction of the Crossrail and of
the stations was not taken in consideration.
Overall, the Crossrail project seems beneficial environmentally in terms
of CO2 emissions.