Number of bicycle commuters: 5,463
Bicycle commuters' share of overall population: 8.5%
Sandwiched between Boston and Somerville, Cambridge's cycling culture is cobbled together from equal measures of college students, long-established bike shops, bustling neighborhoods and squares and a strong community of technology and biotech firms clustered around the Massachusetts Institute of Technology. Each day, cyclists converge on the bike lanes of the Massachusetts Avenue corridor that runs through MIT, touches Genzyme, Sanofi Aventis, Biogen Idec ( BIIB), Akamai ( AKAM) and other firms in Kendall Square, makes its way past the music venues and restaurants in Central Square, speeds through the storefronts, newsstands and tourists in Harvard Square and passes the mini malls and modest homes of Porter Square. Those riders could be from Harvard or MIT, as 21% of Cambridge residents are college students. They could be blue-shirted office workers or white-coated lab techs or they could be Boston commuters who just happened to find a cool place amid the bars, restaurants and Portuguese barbecue of Inman Square. They're all forces to be reckoned with on Cambridge's roads, as added bike lanes and shared lane space has made them as much a part of daily traffic flow as the buses, trucks and cars they share the roads with. The jam-packed bike racks at MIT visible from Massachusetts Avenue bear this out, as do the throngs of riders who flock to Memorial Drive along the Charles River when it closes to vehicle traffic during the weekends.