There is now another reason to maneuver on trains for a chance to secure an empty seat. Passengers in areas near the seats on packed trains may be less at risk of being infected with the new coronavirus.

Experts are now giving such nuggets of advice to people who have no choice but to ride trains while the novel coronavirus outbreak spreads around Japan.

Government measures to deal with the virus called on the public to avoid extended periods in unventilated and crowded spaces and for companies to have employees work from home or stagger their commute times to prevent congestion on the rails.

But many workers and students continue to crowd trains and subways, turning the cars into possible sources of cluster infections.

Experts were asked what measures could be taken to reduce the risks.

Masashi Yamakawa, an associate professor of computational fluid dynamics at the Kyoto Institute of Technology, conducted a simulation in 2013 of how droplets spread within a train car from a sneeze by someone with influenza.

While the study was not directly related to the coronavirus, it showed the areas in the train where contaminated droplets could remain for hours.

Yamakawa used two scenarios in his simulation: a sneeze from a passenger near the train door and a sneeze by a seated passenger between the doors.

After examining the simulated spread of the droplets over several tens of seconds, Yamanaka concluded that droplets expelled near the door covered to a wider area and put more passengers in danger of infection.

The sneezer at the door in the simulation sent out a plume of droplets to the ceiling or between other passengers standing in the area.

In contrast, the seated passenger sneezed downward to the open space above the knees, and the droplets tended to drop to the floor.

A report released in February by a team of experts at the World Health Organization indicated that coronavirus infections could be transmitted via “aerosol” particles that can remain in the air indoors for many hours.

“If aerosol transmission is possible, the chances for infection would likely be greater near the door,” Yamakawa said.

The WHO research team said that while aerosol transmission was possible, it was not considered a major cause of the spread of the infections.

Yamakawa said if the coronavirus spreads in a similar manner as influenza, the likely paths of infection on trains were either through inhaling droplets sneezed or coughed into the air or by touching one’s eyes, mouth or nose with hands that have held contaminated straps or handrails.

One obvious problem on crowded trains is that everyone is jammed together and no one can really know if a passenger in direct contact is infected.

Yoshiaki Katsuda, a professor at the Kansai University of Social Welfare who specializes in the relationship between health and travel, said, “The best answer is not to ride the trains and work from home as much as possible.”

But when using crowded trains is unavoidable, Katsuda said, “The next best step would be to choose trains or train cars with as few passengers as possible.”

He recommended taking local trains rather than special express or rapid express trains. Local trains, he said, are more likely to be emptier, and since they stop at every station on a line, the opening of the train doors helps to ventilate the cars.

Other measures should be considered when riding Shinkansen bullet trains, which rarely become as congested as commuter trains but whose rides are much longer than a typical commute.

Possibly infected passengers may move about in Shinkansen to use the toilet.

“Infection (on bullet trains) is possible by coming into contact with doors, handrails and toilets,” Shinji Yamasaki, a professor specializing in infectious diseases at Osaka Prefecture University, said. “It is important to wash one’s hands well with soap.”

He also suggested wearing gloves and washing hands after leaving trains other than Shinkansen.

The Japanese Association for Infectious Diseases and the Japanese Society for Infection Prevention and Control released guidelines on Feb. 21 for the general public.

Individuals using public transport were instructed not to touch their noses, mouths or eyes with hands that have come into contact with things touched by others, such as straps and handrails.