I've noticed that Youtube use pjax for page navigation a long time.
It strongly improved the user experience. But there's a problem not solved: After user click a link. Instead of showing loading progress by browser, the loading progress is showing by Youtube's page. And before target page load complete, user can't cancel the navigation (through browser's Stop command).
Maybe, that's one reason of why Youtube provide a in-page progress bar. Without it, user can't know whether page is navigating or not.
I'll introduce a solution for it (demo). It makes browser show loading status (yes, you can use in-page progress bar same time), and allow user use Stop command cancel navigation.