Unintentional Street Art in London

Several roads around London are being repaved at the height of the leaf-drop season. What you get, then, is unintended street art where autumn leaves have been pressed into the new tarmac/asphalt/macadam (but not pavement – which is a sidewalk) by traffic or even by the street paving roller. These are unexpected and beautiful additions to the capital's streets, but how long will they last?
   In the above photo, you can see three leaves in the lower lefthand corner which have fallen since re-paving. They will be crushed and dispersed soon by the traffic, wind and rain. But let's see how long the impressed patterns last. This photo was taken on Marchmont Street, Bloomsbury – near the North Sea Fish Restaurant. I have seen other leaf impressions on the Strand near Aldwich, with the impressed patterns standing in stark contrast to older grey tarmac. Where else, anybody?