In New York, increases in the use of ride services like Uber mostly came from bus and subway riders[1]. If we are being charitable to Google, we might assume that this initiative is intended to reduce the same sort of trend. If we are not being charitable, we might assume that this initiative is intended to encourage current bus riders to expose themselves to the product.
[1] https://www.6sqft.com/mta-says-uber-use-is-the-cause-of-nyc-...