Walking a Historical Path
Tokyo, as well as Japanese commerce in general, was structured largely along walking routes in the 16th to 18th centuries. Tokyo has done a good job of preserving its classic street structures, so when you walk down a road in downtown Tokyo, of course the shops have grown from small, one-merchant stands to large buildings and outlet malls, the road itself and moreover the names of the bridges and intersections and landmarks have remained.
For this reason, just walking lengths of Tokyo is a very popular activity for sightseers, and one in particular that has stood as a major thoroughfare for hundreds of years is route 1, the Tokaido. This route leads all the way from Nihonbashi down to the coast and along the southern coastline to Kyoto. This is the main artery which stimulated trade between Kyoto the old capital, and Edo the capital city as Japan came out of its warring age.
See a great snippet of the Tokaido from a Deep Japan friend here: