VicRoads
VicRoads states that a bike lane is able to carry three times as many people as a traffic lane:

Infrastructure Victoria
Infrastructure Victoria states that cycling infrastructure can carry more than double the number of people that a car lane:

City of Melbourne
The Transport Discussion Paper commissioned by the City of Melbourne shows that the space required per person varies significantly between different types of transport:

National Association of City Transportation Officials (USA)
NACTO states that bicycle lanes carry roughly five times more people than a vehicle lane:

London (UK)
Data from London shows that protected bicycle carry five times as many people as a vehicle lane:
Summary
Best practice protected bicycle lanes transport more people than a traffic lane, so re-allocating street space to a bicycle lane will reduce peak hour congestion on the remaining lane, making our streets better for drivers.