Cal. Rev. & Tax. Code § 8510

In order to be eligible for funds derived from the tax, project sponsors shall comply with all applicable commission rules and regulations including, but not limited to, those adopted pursuant to Section 66516 of the Government Code and Sections 99244 and 99246 of the Public Utilities Code. In consultation with cities, counties, transit operators, congestion management agencies, and other interested groups, the commission shall also develop and implement a program to ensure that project sponsors expend funds derived from the tax in an efficient and effective manner. No operating or maintenance funding provided from the tax shall be used to supplant any funds within the discretionary control of the recipient agency that are used for existing transportation operating or maintenance activities.