California gas tax set to increase July 1

How did they add an additional $.5 cents? SB1 increased the tax see below:

This bill would create the Road Maintenance and Rehabilitation Program to address deferred maintenance on the state highway system and the local street and road system. The bill would require the California Transportation Commission to adopt performance criteria, consistent with a specified asset management plan, to ensure efficient use of certain funds available for the program. The bill would provide for the deposit of various funds for the program in the Road Maintenance and Rehabilitation Account, which the bill would create in the State Transportation Fund, including revenues attributable to a $0.12 per gallon increase in the motor vehicle fuel (gasoline) tax imposed by the bill with an inflation adjustment, as provided, 50% of a $0.20 per gallon increase in the diesel excise tax, with an inflation adjustment, as provided, a portion of a new transportation improvement fee imposed under the Vehicle License Fee Law with a varying fee between $25 and $175 based on vehicle value and with an inflation adjustment, as provided, and a new $100 annual vehicle registration fee applicable only to zero-emission vehicles model year 2020 and later, with an inflation adjustment, as provided. The bill would provide that the fuel excise tax increases take effect on November 1, 2017, the transportation improvement fee takes effect on January 1, 2018, and the zero-emission vehicle registration fee takes effect on July 1, 2020.