Worried about the air in your crowded light rail car? Don’t do it, says Sound Transit

Traffic in Washington is again as bad as it was before Covid-19 kept many people off the roads and at home.

Washington State Department of Transportation the data show traffic at 32 locations statewide hovering around 3% below baseline from March 2019 through February 2020 for the past several weeks.

Transit use has rebounded somewhat after plummeting nearly 90% last year, but remains at about half of pre-pandemic levels, according to Sound Transit and King County Metro.

Sound Transit hopes its new light rail service to North Seattle will increase ridership.

The agency says if you’re worried about safety in a crowded train car during a pandemic, you shouldn’t be. Spokesman John Gallagher said Sound Transit’s light rail cars have one of the safest and best ventilated interiors, with air flowing at 12 ACH (air changes per hour). This means that their air is replaced every five minutes.

“This exchange rate is comparable to what you would find in an operating room,” Gallagher said. “And it’s also much higher than what you would find in your typical office building or school.”

“That’s a very good ventilation rate, comparable to hospital operating rooms/isolation wards and in-flight commercial airliners,” said Richard Corsi, dean of engineering at the University of California. to Davis, in an email.

Corsi said many schools and offices have air flowing at just two or three air changes per hour, a rate that aerosol researchers recommend at least double to improve coronavirus safety.

Good ventilation is one of the most important measures to prevent the spread of coronavirus indoors.

Masks are also still mandatory on all public transport vehicles, just like on planes.

Gallagher said that in addition to frequent ventilation, Sound Transit trams have filtration systems fine enough to remove contagious airborne virus particles.

Jose P. Rogers