A.C.A. 27-15-303 Applicability actually reads:
(a) The provisions of this subchapter shall apply only to:
(1) Passenger vehicles, including automobiles;
(2) Light trucks, including vans, with a three-fourths (3/4) ton or less manufacturer's rated capacity if the vehicle is specially adapted for use by disabled individuals through the use of a lift, ramp, hand controls, etc.
I don't have the most current Motor Vehicle and Traffic Law manual here at home and the state code site is down. This manual is the 2003 edition. I can check ACA 27-15-303 Monday to see if anything changed in the last couple of sessions.
A motorcycle would be a motorcycle, motor vehicle, vehicle, and a passenger motor vehicle under definitions found elsewhere in state code. A passenger motor vehicle is defined as all vehicles other than commercial motor vehicles, class one trucks, trailers, and semitrailers. I don't know that "passenger vehicle" is defined anywhere. Vehicle is, and passenger implies other than commercial use.