Bike Paths

Denise, I've had a similar situation approved before. Probably the most important thing is to provide the context to the review team as to why your solution makes sense given the specific situation of your project and how it meets the overall intent of providing paths leading off campus in two different directions.

How can I prove option 3, while building still not constructed yet, so I don't know who are the students and where they are live?

In planning for the construction of the school were there any studies or surveys to determine the location of potential students?

Yes, but all these studies are tentative, and after occupancy the situation may be changed. I cannot decide who will attend the school.

In some cases public or government schools are be planned to serve the population of a particular geographic area and there are policies that influence where students will attend school. In other cases a school may enroll students from a wider area based on test scores or other selection criteria. You'll need to decide how confident you (and the reviewers) will be that you can anticipate where students are likely to live. If don't you think there are enough reasons to expect 80% of students to come from within the "attendance boundary," then Option 3 may not be apply to your situation.