RCW 9.41.050 - Carrying firearms
(2)(a) A person shall not carry or place a loaded pistol in any vehicle unless the person has a license to carry a concealed pistol and: (i) The pistol is on the licensee's person, (ii) the licensee is within the vehicle at all times that the pistol is there.

So what is a vehicle as defined by the state of Washington?

RCW 70.76.010 - Definitions
(12) "Transportation vehicle" means a mechanized vehicle that is used to transport goods or people including, but not limited to, airplanes, automobiles, motorcycles, trucks, buses, trains, boats, ships, streetcars, or monorail cars.

RCW 46.04.670 - Vehicle.
"Vehicle" includes every device capable of being moved upon a public highway and in, upon, or by which any persons or property is or may be transported or drawn upon a public highway, including bicycles. The term does not include power wheelchairs or devices other than bicycles moved by human or animal power or used exclusively upon stationary rails or tracks.

RCW 46.04.320 - Motor vehicle.
"Motor vehicle" means every vehicle that is self-propelled and every vehicle that is propelled by electric power obtained from overhead trolley wires, but not operated upon rails.

RCW 46.04.330 - Motorcycle.
*** CHANGE IN 2009 *** (SEE 5482.SL) ***
"Motorcycle" means a motor vehicle designed to travel on not more than three wheels in contact with the ground, on which the driver rides astride the motor unit or power train and is designed to be steered with a handle bar, but excluding a farm tractor, a power wheelchair, an electric personal assistive mobility device, and a moped.

RCW 46.04.305 - Motor homes.
"Motor homes" means motor vehicles originally designed, reconstructed, or permanently altered to provide facilities for human habitation, which include lodging and cooking or sewage disposal, and is enclosed within a solid body shell with the vehicle, but excludes a camper or like unit constructed separately and affixed to a motor vehicle.

RCW 46.04.570 - Streetcar.
"Streetcar" means a vehicle other than a train for transporting persons or property and operated upon stationary rails principally within cities and towns.

RCW 46.04.440 - Railroad.
"Railroad" means a carrier of persons or property upon vehicles, other than streetcars, operated upon stationary rails, the route of which is principally outside cities and towns.

RCW 47.60.017 - State ferry system.
The legislature finds and declares that the state ferry system is a public mass transportation system. (While I can find no single definition of a ferry as a vehicle or that the ferry runs are classified as a state highway in the RCW's As you can see in RCW 46.04.670-Vehicle & RCW 70.76.010-Definitions, it's covered for all intended purposes.)

RCW 81.104.015 - Monorail
(2) "Rail fixed guideway system" means a light, heavy, or rapid rail system, monorail, inclined plane, funicular, trolley, or other fixed rail guideway component of a high capacity transportation system that is not regulated by the Federal Railroad Administration, or its successor. "Rail fixed guideway system" does not mean elevators, moving sidewalks or stairs, and vehicles suspended from aerial cables, unless they are an integral component of a station served by a rail fixed guideway system.

RCW 7.80.120
Monetary penalties - (for not having your CPL on you)
class 1 - $250 (not including statutory assessments)

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