California Code, Public Utilities Code - PUC § 103301.6

If any demand-activated service or system operated by the district diverts or lessens the patronage or revenues of any existing taxi service by causing a loss of patronage or revenues in the affected service area of any existing taxi service to the extent of 10 percent or more, the district shall not continue its demand-activated service or system, or maintain and operate the service or system, until it has completed the purchase of any existing taxi service or any part thereof.  No purchase of an existing taxi service, or part thereof, need be made by the district as a result of the establishment or operation by the district of any service or system other than a demand-activated service or system.