Sam Schwartz, former commissioner at the NY DOT, had this interesting idea:
"One possible use of the taxi data is to identify clusters of origins and destinations where it can be demonstrated that walking travel times are competitive or can be made competitive to taxi travel times. Then the city can try to make those walking trips more inviting with street designs, lighting, policing, changing signal timing to speed the walking trip, etc. Next, the city should publicize the competitiveness of walking for these trips."
Many more ideas over at Streetsblog.
Thanks to Noah Kazis