No subject

is as much an obstruction as a gate or a fence when on a public right of way
- only a gap is not an obstruction. Stiles etc. need to be specified and
allowed by the highway authority; those that are not specified are illegal
obstructions; those that are specified have to be maintained. So ... I would
say that a stile is a barrier (in law - and for differently abled walkers in
practice - not easy to get a wheel chair over a stile or even an arthritic
hip!).