Critical Mass normally holds a large social bike ride on the last Friday of every month. Yesterday, participants rode in memory of John Corcoran, a bicyclist who died when a driver on Memorial Drive jumped the curb and slammed into him on the sidewalk near the BU boathouse during Monday's afternoon rush hour - but they also rode to demand DCR finally do something to make its parkways safe for people not encased in two tons or more of steel. Read more.