The roadmap of a path used to share an address with its chapters and differ only in the part after the hash, which is why Back to roadmap could change the address without changing the page. The roadmap now has an address of its own: /roadmap/{path}, with its tabs as ?tab=projects, ?tab=interview and ?tab=certificate. Chapters stay at /paths/{path}#step={chapter}.
Back to roadmap, the roadmap tabs, the path library, the home page, the composer and the header trail all link to the new address. Old links and bookmarks to /paths/{path} still work: they open the roadmap at its new address, keeping any tab they named.