Covering screen gaps minimises Covid-19 risk for bus drivers

Covering up gaps around the screen separating bus drivers from passengers is an effective way to reduce Covid-19 transmission risk for drivers while they are in their cabin, according to a study by UCL researchers commissioned by Transport for London. The research team from UCL's Centre for Transport Studies and UCL Civil, Environmental & Geomatic Engineering used computer simulations of airflow to determine the risk that bus drivers might breathe in droplets or aerosols from infected passengers. They found that minimising the gaps around the driver's screen to 5 millimetres reduced the amount of exhaled breath reaching the cabin by 97%, greatly minimising transmission risk. If the driver's cabin window was open, this would reduce the amount of exhaled breath entering the cabin to zero, according to the researchers' simulations. Middle door boarding was introduced by TfL from 20 April as an emergency temporary measure to reduce interaction between bus drivers and passengers. At the time, Londoners were being encouraged to make essential journeys only, passenger numbers were very low (around 15 per cent of normal demand) and 2m social distancing guidelines were in place. In response to the researchers' advice in April, TfL worked with bus operators and the Unite union to introduce extra protection to bus drivers' screens, covering speech holes and covering gaps around the card payment reader and windscreens.