The existing bridge and tunnel at the site, where London's orbital M25 motorway crosses the river, are operating at or above their effective capacity for long periods of the day, according to a DfT study published today. The study recommended that a more detailed analysis should be carried out of three potential sites where a new crossing could be feasible. It also recommended further work to establish whether short-term improvements to journey times could be made by changing the layout of the toll plazas or applying one-way tolling.