How to Make Travel COVID-Safe

Biking is very COVID-safe and should be encouraged. Return-to-school creates a psychological “fresh start,” where new commuting habits may be formed.

The perceived safety of different travel modes will impact their utilization, requiring confidence-boosting marketing to persuade riders to come back. There is a psychological and educational component that cannot be overlooked in these uncharted waters.

The leading edge of transportation COVID safety is focused on improved ventilation. This focus stemmed from the National Academy of Science’s August 26-27 workshop entitled Airborne Transmission of SARS-CoV-2: A NASEM Virtual Workshop, hosted by Dr. Fauci and CDC’s Deputy Director. The workshop concluded that the primary driver of superspreading is small airborne virus particles (aerosols) that travel farther than six feet, resulting in the need to scrub the air.

BART and AC Transit are national public transit ventilation research leaders.

The ventilation on BART cars is 80% recycled and 20% fresh. The recirculated air is filtered prior to being dispersed through the window frame. The air in each rail car is fully replaced fifty times per hour. BART is piloting MERV 14 filters for cars. BART combines their ventilation effort with 14 other safety measures including mandatory masking, “quiet ride” (no talking to reduce the number of virus particles exhaled into the rail car air), maximum occupancy to ensure social distancing, and thorough cleaning. Caltrain is following BART’s lead and we are in communication with Caltrain about both Caltrain and their shuttles.
Using a consumer fog machine that is more-typically used for Halloween Haunted Houses, AC Transit ran smoke tests for multiple air safety scenarios. Opening bus windows created counterproductive turbulence. For maximum safety, bus HVAC is set to provide fresh air and the ceiling hatch in the back is opened, creating positive pressure to exhaust stale in-vehicle air, every 70 seconds. Quiet ride, markings for open and closed seats, and thorough cleaning are also part of every bus’s COVID safety protocol.

Both BART and AC Transit participate in the Bay Area Healthy Transit coalition of transit agencies that have developed confidence-boosting messaging for return-to-transit. Recommended for SFHS buses:

Apply regional best COVID-safety practices to each bus
Using best marketing practices, communicate confidence-boosting messaging to applicable parents, students, and staff.
As an option, we can audit the air safety of these buses by measuring for stagnant indoor air with an NDIR CO2 meter.

As far as safe carpooling in cold weather, two-person carpools following a best practices protocol will be safest (three-person carpools should be avoided). A quiet ride (no talking) with the non-driver sitting in the back on the right (far away from the driver) with two opposite windows open halfway will be safest. This protocol follows computational fluid dynamics analysis by UMass Professor Varghese Mathai and is also informed by Professor Richard Corsi and Stanford Professor Wayne Ott, as well as best safety practices from carpooling apps Scoop and Waze Carpool. Safe three-person carpool protocols will be designed and available in the future.

We envision a stair-step return to the new normal, with gradual increases in transit and carpool utilization, accompanied by updated public health orders that increase maximum occupancy. In a few other countries, public transit social distancing has already been reduced from 6’ to 3’.