The raw data is here from TfL, the people who run the buses in London: https://tfl.gov.uk/corporate/transparency/freedom-of-information/foi-request-detail?refer

The raw data is here from TfL, the people who run the buses in London: https://tfl.gov.uk/corporate/transparency/freedom-of-information/foi-request-detail?referenceId=FOI-2096-1718 https://tfl.gov.uk/corporate/transparency/freedom-of-informa... tl;dr: - single-deckers are ~900g/km, - double-deckers are ~1300g/km - hybrid are 675-780g/km So anywhere between 800% to 1500% worse than a decade-old hybrid. Of course, if the bus has 24 to 45 passengers on it, then it is better on a per-passenger basis than me in my car with my wife and kid. I couldn't find any rider-ship data from TfL, but they often appear kinda empty outside of rush hours.