The ride-hailing businesses of Uber and Lyft have shrunk by more than half in recent weeks compared with a year ago as a result of the coronavirus pandemic, according to people at the companies with knowledge of the figures.

The overall contraction could worsen for both companies as the pandemic’s toll grows and more people stay indoors. For now, the value of fares Uber and Lyft collect from passengers has fallen by more than 50%. At Uber, the impact on ride-hailing revenue could be somewhat smaller because Uber has been paying drivers a lower share of passenger fares than it did last year. Taking that change into account, Uber’s revenue from passenger rides, after paying drivers, is likely to be less than $450 million a month. That compares with about $800 million in monthly passenger revenue that Uber generated in last year’s first quarter.