Pathways: Determining the accessibility of fare gates

When providing directions to users, it's important to
determine whether or not a certain pathway is accessible to people who use
wheelchairs.

When the pathway mode is *Stairs* or *Escalator*, it's clear that the pathway
is not accessible, but it's not obvious for *Fare Gate* or *Exit Gate* -- Ordinary
turnstiles are not, but there might a separate gate that can be opened to
allow a wheelchair to pass.

Has anyone else encountered this issue or developed a workaround, or should we (Transit) propose some additions to the spec to handle this case?