What does this sign mean?

Explanation: Buses and cycles can travel in this lane. In this example, they'll flow in the same direction as other traffic. If it's busy, they may be passing you on the left, so watch out for them. Times on the sign will show the lane's hours of operation; if no times are shown, or there's no sign at all, this means the lane is in operation 24 hours a day. In some areas, other vehicles, such as taxis and motorcycles, are allowed to use bus lanes. The sign will show if this is the case.

Category: Road and traffic signs

References: The Official DVSA Guide to Driving: Section 6, Highway Code: Page 107, Know Your Traffic Signs: Page 32