Page 29 - TrafficInfraTech Magazine - Linking People Places & Progres

PUBLIC TRANSPORT

areas, there are three crucial aspects stations. Underground stations are As social
that need to be addressed before metro closed, so they primarily rely on air distancing
start running again. conditioning maintained through a mix
of 10% fresh air and 90% re-circulated continues into
i) Mitigation of contagion risk through
air conditioning and ventilation at air, which can contribute to spreading the foreseeable
stations and inside coaches the disease. future, streamlining
Metro agencies, such as Chennai
ii) Operations planning under social other aspects
distancing norms, and therefore Metro, have previously experimented
reduced carrying capacities with suspending air-conditioning of operations
services at platforms and concourse
iii) Crowd management and control levels. However, considering Indian such as crowd
inside metro coaches and stations heat and the station’s design (which management,
reduced natural ventilation), air-
Air-conditioning and conditioning had to run at a reduced last-mile
ventilation capacity. This capacity also depends on connectivity, and
As everyone knows by now that passenger footfall at the station and air conditioning &
COVID-19 virus spreads through can be experimented with during peak
droplets when an infected person and non-peak hours. ventilation will be
coughs or sneezes. This poses a risk Metros should explore measures to vital for ensuring
for passengers, as metro systems are infuse fresh air and use air conditioning
high interaction systems and heavily intermittently to maintain comfortable that taking the
dependent on air-conditioning to temperatures. Stations and metro metro remains a
maintain a comfortable temperature coaches that have limited ventilation
and ventilation for passengers inside would need to keep their temperature viable and efficient
stations and metro coaches. between 24-27 degrees Celsius and mode of public
For elevated stations, natural relative humidity between 40-70% by transport.
ventilation provides air circulation; these allowing in fresh air regularly, according
stations have a lower proportion of to guidelines from the Indian Society
recycled air compared to underground of Heating, Refrigerating and Air
Conditioning Engineers (ISHRAE), a
professional group.
Metro agencies in India can also focus
on air filter technology and sanitization
measures as they resume services.
International metro agencies are using
air filters of a certain classification that
can capture the virus, even in droplet
form. Similarly, Indian metro agencies
will need to invest in air filters that can
trap infectious material and mitigate
the risk of spreading the virus through
recycled air. Increasing the frequency
of sanitizing and replacing air filters will
also have to become part of the metro’s
maintenance activities. As a metro train

www.trafficinfratech-com-500653.hostingersite.com April-May 2020 / TrafficInfraTech 29