Or you know, just build it in:
http://kotaku.com/final-fantasy-xv-s-first-half-is-open-world-but-it-s-s-1785784414
“As for Final Fantasy XV’s structure, it has both an open world part and a linear part. The open world element continues throughout the first half, and because of the story, the second half progresses linearly.”
― El Tomboto, Monday, 29 August 2016 14:24 (seven years ago) link
As noted in the article, that's the reverse of the traditional FF formula where it's super linear to begin and becomes more open world at the end
― Nhex, Tuesday, 30 August 2016 01:07 (seven years ago) link