Notwithstanding any other provision of this part, before the district may establish any demand-activated service or system which may, at any time, divert, lessen, or compete for the patronage or revenues of any existing taxi service, the district shall give a written notice to that service. The written notice shall describe the demand-activated service or system which the district proposes to establish and shall state the time within which the district proposes to establish such service or system.