With-flow cycle lane

This blue sign marks a with-flow cycle lane: cyclists use it in the same direction as the traffic beside it. Give cyclists room, and do not drive or park in a cycle lane marked by a solid white line during its times of operation (Highway Code rule 140).

Official Highway Code caption: “With-flow pedal cycle lane.”

Listed under “Signs with blue circles but no red border mostly give positive instruction.” in The Highway Code: traffic signs (GOV.UK). For every sign in more detail, see the Department for Transport’s Know your traffic signs.