There was a similar project done for the NYC subway system done 6 years ago: http://www.visualcomplexity.com/vc/project_details.cfm?id=698&index=698&domain= htt

There was a similar project done for the NYC subway system done 6 years ago: http://www.visualcomplexity.com/vc/project_details.cfm?id=698&index=698&domain= http://www.visualcomplexity.com/vc/project_details.cfm?id=69...