Metrolinx has proposed a parking levy of about $0.25 per space per day. Details are not entirely clear, but it seems this would be across the GTHA and would be levied on property owners. This also should create a small but significant incentive towards using public transport. Even if employers and merchants do not immediately pass the cost on to staff or customers, it will certainly discourage provision of parking spaces.
Some European and Asian cities have introduced strict controls on parking provision. London has strictly controlled the provision of non-residential parking in the central area since about 1963. While suburban retailers usually provide free parking to customers, it is tightly controlled and usually time-limited. More recently, the London Government has also restricted the provision of residential parking, sometimes allowing less than one parking space per apartment.