Sections 291-3.2 and 291-3.3 shall not apply to a motor vehicle for hire which has been issued a certificate of public convenience or necessity, 1-7 passenger classification by the public utilities commission so long as the motor vehicle has a barrier between the driver and the passengers sufficient to prevent intoxicating liquor from being passed between them and only the passengers behind the barrier consume the intoxicating liquor.
HRS § 291-3.4