Eric Fischer is an artist, who develops some really good techniques to understand maps.
Different maps are created to study the photographic movement and traffic activity in a city, which reveal how heavily roads are used. Here in this map the photographer Eric Fischer has combined ideas, heavy roads and the photographs taken by geotags of photos uploaded. What has emerged is a map of human interest. Places that are more fascinating have the maximum clicks and others have the lesser clicks.
Fischer used colour coding on the maps. Apparently, Fischer was able to guess the picture taker’s mode of transportation—presumably using the time stamps and distance travelled between a user’s pictures. He then created a colour code: Black is walking (less than 7mph), Red is bicycling or equivalent speed (less than 19mph), Blue is motor vehicles on normal roads (less than 43mph); Green is freeways or rapid transit.