It's crystal clear until it's not. In the UK a bicycle is, rightly so, considered a vehicle. I know this, but I'd guess many British people do not. I also understand why bicycles are considered vehicles and, when on my bike, tend to follow the spirit of rules and designs that appear to prohibit vehicles.

I would not ride in the park, but would walk my bike in the park. I'd be breaking the rules but adhering to the spirit of them.