Transport for London (TfL) will launch a trial of centre door-only boarding on routes operated by Abellio from its Walworth garage.
The trial, which begins this week, has been put in place to further protect drivers.
It follows the addition of an extra layer of protection to the anti-assault screens fitted to buses and installation of signage to discourage passengers from sitting near the driver.
Several bus staff in the capital have died of coronavirus COVID-19. The figure stood at five on Monday 6 April but it believed to have increased since then. A driver with First West of England, Martin Egan, is believed to have been the first bus driver in the UK to have died of coronavirus COVID-19.
If the centre door-only boarding trial at Walworth is successful, TfL says it will be rolled out to other garages and routes.
When boarding via the centre door, there is no requirement for passengers to ātouch inā with their Oyster or contactless payment card. TfL says the work required to locate card readers would delay the trial. Its priority was starting it as soon as possible, a spokesperson told routeone.
TfL has reinforced its message that travel by public transport in the capital is only for essential journeys. It has seen patronage drop by 85% from pre-coronavirus COVID-19 levels.
Many transit agencies in the United States have already prohibited boarding via the front door with the exception of wheelchair users and others with mobility issues.