Many roads nowadays have a "one way only - bicycles excepted" to indicate the road is a one way road but bicycles are an exception to the rule and there's a contraflow bike lane. Most parks that have a no vehicles allowed sign is likely to have a bicycle excepted sign underneath.

Bicycles are vehicles and there is no ackshully that will change that. If you're trying to win an argument with the technicality that everyone would ignore a "no vehicles" sign on a bike that isn't an argument that disproves a bike is a vehicle. All it shows is that a bike is a special vehicle with special rules and exemptions to "no vehicle" signs.

There is no pedantry in calling a bicycle a vehicle. It's obviously a vehicle - it's entire purpose is to be a lightly-mechanized means of transit! Now if we see a sign in a park that says "no vehicles" many people - using our cultural knowledge and context - will interpret the intent of the sign as a reference to "[motorized] vehicles".

Those people are wrong. It's as simple as that. In the eyes of the law bikes are vehicles nearly everywhere. It's settled and not up for debate or discussion.

I believe the entire point of the exercise is to demonstrate people will argue that the sky isn't blue.