No. There is no categorical exemption of private companies from the controlled substance and alcohol testing requirement. Recipients of Urbanized Area (§ 5307), Capital Investment Grant (§ 5309) and Rural Area (§ 5311) funds must conduct drug and alcohol testing of all employees or contractors performing safety sensitive functions. Ride-sourcing companies are subject to the testing requirement to the extent they are a contractor of a recipient and perform a safety sensitive function. However, ride-sourcing companies may qualify for the taxicab exception.