Bus lane, but buses not using it

What is the bus lane for when the buses are traveling outside the bus lane adding on to the congestion. Bus lane are for buses only especially in town areas, differentiate by a red line instead of a yellow line.

Should LTA also impose a fine for buses not using the bus lane? Cos the LTA's price tag for cars captured using the red bus lane is not cheap.

Oh, by the way, picture was taken from my Mirror view :) so it may look abit weird..