For the last two weeks, Sri Lankan doctor Thusitha Kahaduwa has left his car in the garage and done his patient rounds by bicycle, spending hours each day criss-crossing the commercial capital Colombo.
The 41-year-old is among countless thousands, many of them middle-class professionals, who have switched to two wheels for everything from work commutes to grocery shopping after the country - mired in its worst economic crisis since independence in 1948 - all but exhausted its fuel supplies.
