You never realized the signs for NO TRUCKS on the state parkways? 2500’s and up are commercial vehicles. (unless you install a cap and leave it on you can change the reggie)What do you mean, 'you’re technically not allowed on parkways'? Where is this you're talking about? Are there restrictions on what type of trucks can drive on certain roads? As down-right oppressive as King Co/Washington state is, I know of no restrictions concerning pickup trucks; heavy construction rigs, semis, and the like sure, but not 3/4 or 1 ton trucks.
Also no commercial vehicles in the left lane of the expressway.
I see many trucks make their way to the parkways and maybe never get caught.
If you don’t install a cap and prove it to DMV you’ll get commercial plates in the mail. JSYK