I very much enjoy using NProgress.js (http://ricostacruz.com/nprogress/). Very similar to this library, but with the added benefit of a random increment function that allows you to show progress without knowing the specific position.
NProgress.js natively requires jQuery (1.8+). If you don't want to use jQuery as a dependency, there's a PR on github that uses CSS instead https://github.com/rstacruz/nprogress/pull/28