> So is the goal is to mark the route you would take? Sounds interesting.

Basically yes, the Blue Book works on turns so you would mark the turns.

So for the example I gave above (Australian High Commission - Paddington) you might mark the turns:

      ALDWYCH
      CATHERINE ST
      RUSSELL STREET
      DRURY LANE
      HIGH HOLBORN
      PRINCES CIRCUS
      ST GILES HIGH STREET
      EARNSHAW STREET
      NEW OXFORD STREET
      OXFORD STREET
      GT PORTLAND STREET
      MARGARET STREET
      CAVENDISH SQUARE
      HENRIETTA PLACE
      MARYLEBONE LANE
      WIGMORE STREET
      DUKE STREET
      MANCHESTER SQUARE
      MANCHESTER STREET
      GEORGE STREET
      EDGWARE ROAD
      HARROW ROAD 
      HARROW ROAD ROUNDABOUT
      BISHOP'S BRIDGE

> between them at a given time of day

Yes, I guess it could give you extra points for choosing less busy routes during rush hour.

Thanks for explaining!