Every bus in London

Methodology

Live vehicle positions from the Department for Transport's Bus Open Data Service, bounded to Greater London. Every English operator is legally required to feed BODS, which is why this exists at all — TfL's own API publishes arrival predictions at a stop rather than where the bus is. About 94% of what reports inside the box is TfL's; the rest are coaches and county services passing through, and they are drawn separately rather than counted as London buses. Positions are SIRI-VM XML, roughly 7.5 MB per refresh, parsed on the server so a browser never sees it. A bus reports no speed, so these dots ease toward each new fix rather than being projected forward.