It's possible that the rider was hit when trying to cross the street here on the crossing or was hit from behind.
It's a sad scene to see the solitary bouquet of flowers there, and the article doesn't state why it is thought to have been placed in relation to the crash.
This follow-up article suggests, perhaps on scant evidence, that the scene of the crash may have been near the Chessington Close bus stop, here:
https://www.google.co.uk/maps/@51.358434,-0.277528,3a,75y,316.08h,82.99t/data=!3m6!1e1!3m4!1s6qkydMF91Pc_4CKDHjykpQ!2e0!7i16384!8i8192
https://www.getsurrey.co.uk/news/surrey-news/gallery/ewell-crash-flowers-left-scene-22431918
It's possible that the rider was hit when trying to cross the street here on the crossing or was hit from behind.
It's a sad scene to see the solitary bouquet of flowers there, and the article doesn't state why it is thought to have been placed in relation to the crash.