How safe is it to travel on public transport amid COVID-19?

    20 Nov 2021

    Public transport is the most eco-friendly component of the urban environment, as it can significantly reduce the “carbon footprint” of a city dweller and save resources – there is no need to use a private car. In 2020, a pandemic and accompanying lockdowns dealt a powerful blow to municipal transport. How are things going after almost two years? Have medical workers rated public transport as safe? This will be discussed in our selection.

    The first and newest analysis, published on November 12, 2021, we’ve found on News-medical.


    Since late 2019, the world has been dealing with the coronavirus disease 2019 (COVID-19) pandemic and has been facing an overwhelming challenge of controlling the spread of the disease. In most countries in which there have been increased cases of COVID-19, local governments have implemented restrictions, such as lockdowns and social distancing, to slow the spread of the disease. Research has shown that such restrictions are imperative in reducing the spread of COVID-19.

    In South Korea, public transportation systems are mainly made up of buses and urban rails. However, since the pandemic began, the demand for public transport has drastically dropped. To offer the safest possible environment on public transport, the government of South Korea has issued safety guidelines, including maintaining a safe distance from others, wearing face masks, traveling at off-peak times, and avoiding crowded spaces.

    However, the use of public transport is still considered high risk due to the high transmissibility associated with COVID 19, and large numbers of people are asymptomatic. Thus, high levels of anxiety regarding public transport are justified, especially in those considered vulnerable. Several studies have shown that public transport is a significant source of transmission regarding the pandemic.

    The study

    Close contact is typically considered the main route of transmission with COVID-19, which highlights the significance of asymptomatic individuals. Thus, it is vital to examine patterns of travel and the activities of infected individuals to protect the population better and control the spread of COVID-19.

    In public transportation research, previous studies have utilized various frameworks or networks, such as Euclidean, Neural Network, and Reverse Logistics Network, to simulate the trip characteristics and travel patterns of passengers in public transportation. Another previous study used smart card data to examine the public transportation passenger encounter pattern with an Encounter Network.

    In this study published in Science Advances, the authors extended this research by proposing a time-varying weighted Public Transportation Encounter Network that modeled the COVID-19 infectious process observed on public transport. The public transport trips analyzed in this study showed a repeated mobility pattern of regularity, which allowed for reproducible patterns. Therefore, the familiar stranger group (frequent encounters of public transportation users) was analyzed. The simulation performed displayed how public transportation users are frequently exposed to the virus on their trips.

    Mask wearing is a recommended safety procedure in South Korea to help prevent the spread of COVID-19. However, it is mandatory in public places such as public transport. The authors tested the efficacy of the most common masks worn in South Korea by determining the number of concentrations and reduction rate before and after wearing the mask. The authors prepared a 5% TiO2 Gamble solution to mimic pulmonary fluids and viral particles and converted it to cough aerosols using a mist generator. The results from this procedure demonstrated that mask-wearing is as effective as maintaining two meters physical distance.

    Large-scale events and mass gatherings can increase the spread of COVID-19 through travelers who attend such events and carry the virus to new areas. Also, in the case of large events, it can mean increased numbers and duration on public transport, which increases the number of public encounters, thus increasing the chance of COVID-19 transmission. The public encounter network demonstrated that variation in the demand for public transport based on time zone could significantly affect congestion levels. Therefore, the variation in congestion levels generated different encounter patterns in the public transportation network. Moreover, the authors of this study demonstrate that the duration of contact with infected citizens was closely related to congestion on public transport.


    Close contact is typically the primary route of COVID-19 transmission, highlighting the danger associated with asymptomatic cases. A better understanding of patterns of travel may help in mitigating COVID-19 spread on public transport. The wearing of masks, while still a controversial topic, is mandatory on public transport in South Korea. The results from this study show that wearing a face mask may be as effective in preventing the spread of COVID-19 as keeping a two-meter physical distance. Mass gatherings generally result in increased numbers on public transport, so safety precautions such as masks are vital in preventing an increase in COVID-19 cases.

    The second piece of analysis belongs to Sky News. Keep in mind that all the data was relevant to October 2020.


    Coronavirus: Why public transport could be safer than we thought


    The health measures used on public transport have helped prevent the virus spreading, an aerosols expert said.

    The risk of coronavirus spreading on public transport has remained substantially low through the pandemic, several international studies have shown.

    Safety measures imposed on public transport worldwide since COVID-19 hit have made them “the safest places on earth”, Dr Julian Tang, a professor of respiratory sciences at Leicester University, told Sky News.

    The latest (2020) data from France shows only 1.2% of the country’s 2,830 coronavirus clusters – three or more cases from one place or event in seven days – recorded between 1 May and 28 September (2020) occurred on any type of transport (planes, boats and trains). Two-thirds of them were recorded as being transmitted at businesses, school and university environments, public and private events and health centres.

    Hong Kong, one of the most densely populated places in the world and where public transport is heavily relied on, has recorded an overall infection rate of 68 cases per 100,000, far less than Western countries such as the US which has 2,198 per 100,000 and Spain which has 1,602.

    Although there is no expert consensus, some researchers suggest the widespread use of masks could be one of the main reasons for the low transmission rates in Hong Kong.

    Dr Tang said: “In Asia, there was already a culture of being very vigilant on public transport, so they were using masks in Singapore and Hong Kong as soon as they learned of the virus.”

    In Japan, the strategy to contain the virus did not rely on mass testing or national lockdowns, but on urging people to stay away from the “three Cs” – closed spaces, crowds and close-contact settings in which people are talking face-to-face.

    Japan’s approach was based on finding the places with the most outbreaks and determining their common characteristics, Science Magazine reported.

    Gyms, pubs, music clubs and karaoke bars had the most outbreaks and all went against the three Cs.

    Public transport also had those characteristics, but no clusters have been traced back to the country’s busy rail network.

    “In Japan, you’re not allowed to talk on the subway, so despite the Tokyo Metro being one of the busiest in the world, they managed to stay safe as they were also wearing masks,” Dr Tang said.

    Public transport expert Mohamed Mezghani, secretary general of the International Association of Public Transport (UITP), told Sky News: “Public transport was stigmatised at the beginning of the pandemic and as a result rail stations, trains and buses were disinfected regularly from early on.

    “The wearing of face coverings, in pretty much all countries, was also made mandatory early on.”


    Droplets and aerosols transmission

    COVID-19 is often transmitted from an infected person through droplets generated when they talk, cough, sneeze or exhale.

    Some of these convert into aerosol particles, which are lighter than droplets and can be spread further and remain in the air for longer – and anyone who inhales them can become infected.

    Several studies have concluded that the transmission of droplets and aerosols can be prevented, or at least limited, by using a face covering, even in more confined spaces such as public transport.

    There is also less interaction between people on public transport, so the relative lack of speaking, shouting and laughing reduces transmission.

    Eating and drinking is banned on many transport systems around the world and happens very little where it is not banned, meaning those aerosols from eating and drinking are not spreading.

    People also generally stay on public transport for less time than if they are in the office or at a restaurant, again minimising exposure.

    Social distancing is also key, with many governments reducing public transport capacity during the pandemic.

    Ventilation also plays a major role in preventing aerosols remaining in spaces.

    “Transport systems increased their ventilation so they are actually much safer than other smaller spaces,” Mr Mezghani said.

    “Ventilation isn’t done through windows, you don’t necessarily feel it as it’s done mechanically.

    “Long-distance trains actually have some of the best ventilation, the French high-speed trains renew air every 2.5 minutes, others are every five minutes.”

    Some of the droplets from an infected person are too heavy to remain in the air so fall on floors and surfaces.

    Touching those surfaces and then touching your eyes, mouth or nose increases the risk of transmitting the virus – and we touch our face 20 times an hour, on average.

    That is why cleaning hands and surfaces is so important and is something public transport systems started increasing straight away.

    Transport for London (TfL) now uses a cleaning substance similar to the ones used in hospitals and installed 1,000 hand sanitizer points across its network.

    Network Rail has added a warning system on its app to notify passengers if a station is busy, trains and “high-touch” areas in stations are being cleaned more frequently and extra train carriages are being provided where possible to facilitate social distancing, while hand sanitiser is provided in stations.

    But, “the effectiveness of hand hygiene is increased when combined with other measures, such as face masks,” a SAGE paper found.


    Public transport usage remains low

    Despite the evidence from several countries of few infections connected to public transport, this might be due to a lack of data and resources.

    It is easier to detect clusters in places that already have the infrastructure, such as hospitals or schools, but it is harder to identify them from public transport.

    Dr Tang added: “If people follow precautions everywhere, it can be effective – as seen across Asia and then Europe – but if people don’t continue to follow them then there’s a risk.

    “It’s not just the public transport company or government’s responsibility, it’s a social contract by the public to adhere to rules to keep people safe.”

    But, the low number of reported transmissions from public transport might also be affected by a drop in use.

    Private vehicle usage is back to pre-pandemic levels, while trains and buses are still down by 60-40%.

    In London, Birmingham, Madrid and New York, Apple found the number of people searching for directions on public transport through Apple Maps was lower than at the beginning of the year.

    It appears the stigma against public transport is still there and risks negating any positive impact on climate change not using cars had during peak lockdown.


    The third article that we’ve found for you is BBC analysis relevant on May, 2021.

    What’s the risk of COVID-19 on public transport?


    The number of people using public transport is far lower than before the pandemic, but it’s rising steadily.

    What are the risks of catching Covid for those who need to travel?

    How safe are trains and buses?

    A lot depends on how crowded a bus or train is, and how much distance you can keep from other people.

    Scientists recognised these potential dangers early in the pandemic.

    Dr Julian Tang, a clinical virologist at the University of Leicester, says a key concern is sharing enclosed airspace, because coronavirus particles linger in the air.

    “If you’re close enough to smell someone’s garlic breath on public transport,” he says, “then you’re also potentially inhaling any virus that’s carried with it.”


    What can I do to protect myself?

    Wearing a mask can lessen the risk, as can keeping windows open to encourage air flow.

    The chance of picking up the virus from contaminated surfaces is now believed to be far lower than previously thought.

    The main US health agency, the Centers for Disease Control (CDC), says the chance of catching Covid via contaminated surfaces is less than one in 10,000.

    A study by Imperial College London for Transport for London in February tested samples from escalators, buttons and handles and found no traces of the virus.


    What safety measures are operators taking?

    As numbers increase, rail companies are increasing capacity, to enable social distancing and prevent packed trains.

    The Rail Delivery Group says more than 1,000 weekday services have been added since mid-February, with more planned in May.

    There will also be longer trains, to make it easier for people to socially distance.

    As well as more hand sanitiser at stations, there will be enhanced train-cleaning too.


    Train seating plan

    Transport for London says trains, trams, buses and stations on its network will continue to be treated with hospital-grade cleaning substances that kill viruses and bacteria.

    It also says capacity limits will remain in place on all buses, with the exception of dedicated school services.


    What is the risk on planes?

    The most significant COVID-19 risk for people traveling by plane is where they go and what they do either side of the journey.

    The risk on a plane is relatively low because of how often the air inside the cabin is circulated.

    Most planes have something called a high-efficiency particulate air filter (Hepa). This can capture smaller particles than ordinary air-conditioning systems, including some viruses.

    It mixes fresh air from outside the plane with air already in the cabin.

    “Planes are probably the safest environments on the planet because they have this massive air change rate of 20-30 air changes per hour,” said Dr Tang.

    That compares to about two to four air changes per hour in a typical office, and four to six per hour in common areas in hospitals.

    But it may be harder to socially distance from others on a plane, so wearing a mask remains important.


    Will vaccines make a difference?

    More than 37 million people in the UK have now been vaccinated.

    This is a significant number of people who are less likely to become seriously ill if they catch coronavirus. There’s also increasing evidence vaccinated people are less likely to pass the virus on.

    However, that still means many people are susceptible, so travellers need to continue following COVID-19 guidelines.

    “Some measures should be maintained for a while,” says Dr Shengjie Lai, a senior research fellow at the University of Southampton.

    “Face coverings and hand sanitizer on public transport and in substantially enclosed public areas of transport hubs are still very important.”


    Will these measures be in place forever?

    It depends on how much risk people want to live with, according to Dr Tang.

    “Going forward, people may choose to wear a mask – without any fear or stigma – on public transport, like you’ve seen in south-east Asia after the Sars outbreak in 2003.”


    The fourth compilation belongs to The Babel. Let’s check it.


    Public transport resumes operations around the world. Will this contribute to the growing spread of coronavirus? It doesn’t seem so


    Countries are gradually quarantining. Public transport also resumes normal operation. Scientists used to believe (at the beginning of the pandemic – Ecolife) that it contributed to the spread of the coronavirus, but there is growing evidence that this is not the case. In Milan, the number of COVID-19 patients has not increased significantly since the resumption of public transport. And in Hong Kong, where the subway is used by millions of passengers every day, the total number of people infected with the new coronavirus is 1,113 people. Babel discusses the extent to which public transport affects the spread of the coronavirus and whether it can lead to new outbreaks.

    In April, a month after New York became the epicenter of a coronavirus outbreak in the United States, the Massachusetts Institute of Technology published a report stating that public transportation was a major factor in the spread of the disease in the city. It was said that the New York subway, which is used daily by five and a half million people, has become “a significant, if not the most important, source of the spread of the coronavirus.”

    The authors of the report did not track each case of infection before the trip in the transport, but simply compared the ZIP-codes (еhe zip code system used by the U.S. Postal Service) of houses of people with COVID-19, with a map of the city subway. Because of this, a number of scholars criticized the work, but it still gained resonance in the United States. Some officials have called on New York State Governor Andrew Cuomo to stop the subway to reduce the rate of infection. He refused. According to the transport company Transit, before the report, the number of passengers decreased by 74 percent in New York, by 79% in Washington and 83% in Boston.

    New York was far from the only city whose transportation system was damaged by the pandemic. Transport use has also dropped to 80% in a number of European cities: Berlin, Rome, Milan and Madrid. Now that countries are quarantining, passenger traffic is gradually recovering. However, the number of people using public transport is less than before the pandemic. Only 50% of Berlin and Tokyo subways currently (spring 2020) run.

    Passengers do not consider public transport safe, so carriers are introducing new rules for the use of railways, subways and buses. In the UK, all public transport passengers are required to wear masks. The government also urges subway passengers to keep a social distance. In May, the European Commission introduced a series of measures to help travel safely by rail across the continent. These include reducing the number of passengers on trains and increasing the frequency of flights.

    But there are more and more studies on whether public transport increases the risk of spreading the coronavirus. French scientists studied in Paris 150 clusters of coronavirus infection, which were detected from May 9 to June 3. The researchers concluded that none of them had anything to do with public transport systems. The situation is similar in Austria, where none of the 355 outbreaks have occurred in transport.



    If being in the subway or bus increased the risk of contracting the coronavirus, a large-scale outbreak could be expected in Hong Kong, where 12.9 million people used transport every day before the pandemic. However, as of June 17, only 1,113 cases of COVID-19 were recorded in the region.

    In Japan, one of the busiest transport systems. The number of coronavirus cases in a country with a population of more than 125 million does not exceed 17,000. At the same time, most cases of infection can be associated with gyms, pubs, concert halls.

    According to Hitoshi Oshitani, a virologist and health expert at the University of Tohoku, this is due to the fact that passengers on the Japanese subway usually do not talk to other people and wear masks.

    In cities that have been severely affected by the coronavirus, such as Milan, the launch of public transport has not led to an increase in coronavirus infections. After the peak incidence in South Korea, an outbreak of the disease was recorded in the capital, Seoul. But it was also not related to transport – the increase in morbidity was influenced by the opening of nightclubs.

    According to The Atlantic, all this may mean that the greater health risk is not a trip on public transport, but where and from where a person goes. After all, a train or bus where people are silent and wearing masks can be safer than establishments where many visitors talk.


    We’ve got news for you about the future of transport: electric air taxis gear up for lift-off after boosting from the regulator. Check this out here!

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