How can an already bike-friendly city such as Copenhagen entice even more of its citizens to ride? A research group led by Carlo Ratti of the Massachusetts Institute of Technology’s SENSEable City Lab hopes to find out by distributing smart tags to cyclists that track the routes they take and allow them to connect with one another. Together Copenhagen and M.I.T. will distribute by November about 1,000 smart tags, each costing less than $30 and subsidized by the research group, so riders will have been using them for a time before the United Nations Climate Change Conference hosted by the city in December. As cyclists whiz past wireless hotspots, the tags will register passage, tracking bike routes taken. Back home, riders will be able to log on to Facebook to find out which other riders crossed their path that day, as well as to see who has accrued the most miles—a kind of friendly competition. Wider use of tags could help spur a city’s population to bike more instead of drive. And by examining where people are actually riding, Copenhagen could decide where to put bike lanes and monitor where bike congestion occurs. The city would receive only aggregated data to protect privacy, says Christine Outram, a researcher at the M.I.T. lab.

Together Copenhagen and M.I.T. will distribute by November about 1,000 smart tags, each costing less than $30 and subsidized by the research group, so riders will have been using them for a time before the United Nations Climate Change Conference hosted by the city in December. As cyclists whiz past wireless hotspots, the tags will register passage, tracking bike routes taken. Back home, riders will be able to log on to Facebook to find out which other riders crossed their path that day, as well as to see who has accrued the most miles—a kind of friendly competition.

Wider use of tags could help spur a city’s population to bike more instead of drive. And by examining where people are actually riding, Copenhagen could decide where to put bike lanes and monitor where bike congestion occurs. The city would receive only aggregated data to protect privacy, says Christine Outram, a researcher at the M.I.T. lab.