Bus Lanes. These are shown by road markings and signs that indicate which (if any) other vehicles are permitted to use the bus lane. Unless otherwise indicated, you should not drive in a bus lane during its period of operation. You may enter a bus lane to stop, to load or unload where this is not prohibited
Only vehicles shown on the sign may use the lane during the times of operation, which are also shown on the sign. Outside those periods all vehicles can use the bus lane. Where there are no times shown, the bus lane is in operation for 24 hours a day. Don't park or drive in bus lanes when they are in operation.
Driving - The essential skills - pg 111
You MUST NOT overtake if you would have to enter a lane reserved for buses, trams or cycles during its hours of operation.
Lee High Road Bus Lane
Eltham Road Bus Lane
Downham Way Bus Lane
Burnt Ash Road (Sainsbury's)
Burnt Ash Road (South Circular Road)