A major upgrade of William Street is part of the $680 million Cross City Tunnel project.
As a result of the Cross City Tunnel, traffic on William Street was predicted to reduce, which enabled the introduction of a cycle lane, a daytime T2 transit lane and one general traffic lane in each direction. T2 transit lanes can be used by motor vehicles with 2 or more occupants, buses, taxis, cyclists and motor cyclists.
Footpaths have been widened, parking bays created, new street furniture installed and more than 80 new trees planted to create a boulevard effect.
The upgrading of William Street to an urban pedestrian boulevard was completed in May 2006.