Virtual speed bumps cut traffic speeds in Southwark Street

As part of the experimental 20 mph speed limit on Southwark Street, TfL this summer painted 'virtual' speed humps onto the carriageway, which appear as a 3D object when viewed by approaching motorists.

"An initial study found that these road markings, which create an optical illusion, were very effective and show a reduction of up to 3 mph," said transport commissioner Mike Brown in his report to this week's TfL board meeting.

"They are a cost-effective alternative to the traditional hump and are quick to install.

"We will continue to monitor their use and assess the potential for the rest of the network."