'Intervisibility' is a technical term used in highway engineering, which in plain language simply means users being able to (mutually) see each other.

A good example of this term in use is a perpendicular (cycle) crossing of a road. When crossings are perpendicular, and the users are approaching each other at a 90° angle, the intervisibility is good, as each user is able to see the other approaching the conflict point.

The crossing shown below (of a cycleway crossing a side road) has good intervisibility.

Cycleway priority across side road with good intervisibility