The Public Transit Group was launched in January 2009 and has grown significantly since then. As of May 2013, the group has over 19,800 members across 11 subgroups, making it the largest public transit group and ranked 1,486 out of 1.6 million groups on the platform. Membership has increased steadily each month since inception, with an average monthly growth rate of 8% and occasional higher growth months of over 10%. Member participation in discussions and comments has also increased over time.