(a) Specified types or classes of vehicles means any types or classes of vehicles specified by the Commissioner of Transportation whether defined by the Vehicle and Traffic Law or described by dimension, carrying capacity, occupancy, design or actual use, or otherwise by such commissioner in orders adopted by him from time to time, and shall include, but not be limited to, express buses, taxis, commercial vehicles and multiple occupancy vehicles as defined in this Part, and vehicles holding specified permits or licenses issued by the NYS Department of Transportation or other governmental entities.

(b) Multiple occupancy vehicles means any vehicle with a driver and one or more other persons, the number of such other persons shall be as specified by the Commissioner of Transportation in orders adopted by him from time to time with respect to any highway designated under this Part.