"The BIKE TRAIN takes a ‘safety-in-numbers’ approach to cycling. Creating a fun, visible and more protected environment within a mass-ride, it hopes to make it easier for more people to commute by bike along the Lewes Road - reducing traffic-related air pollution and CO2 emissions in the process!"
http://biketrain.org/index.php?page=about
http://www.theargus.co.uk/yourargus/letters/8186542.No_train_gain