Cal. Bus. & Prof. Code § 5273

For the purpose of this chapter, advertising displays advertising those businesses and activities developed within the boundary limits of, and as a part of, an individual redevelopment agency project may, with the consent of the redevelopment agency governing the project, be considered to be on the premises anywhere within the limits of that project when all of the land is contiguous or is separated only by a public highway or public facilities developed or relocated for inclusion within the project as a part of the original redevelopment plan for a period not to exceed 10 years or the completion of the project, whichever first occurs, after which Sections 5272 and 5405 apply, unless an arrangement has been made for extension of the period between the redevelopment agency and the department for good cause. The 10-year period for existing displays shall commence on January 1, 1986.