The details of the proposed $8.5 billion transportation tax are being agreed upon in a compromise by Sacramento-area power brokers. If it qualifies for the ballot, the measure would need at least need 50% approval from voters. The proposed measure would raise the county sales tax by 0.5% for the next 40 years to fund transportation projects across Sacramento County. The proposed funding plan also includes a Regional Transit light rail extension to the Sacramento International Airport, as well as maintenance of the American River Parkway and new bridges. Last week, proponents of the tax filed more than 75,000 signatures with the county to place the measure on the November ballot.