Static fields vs Session variables

So far I’ve been using Session to pass some variables from one page to another. For instance user role. When a user logs in to the web application the role id of the user is kept in Session and that role is checked at different parts of the application. I’ve recently started thinking why not use static members instead. I can store the same information in a static field and easily access it anywhere in my application (well anywhere the namespace in which that static field resides is included.) I know that using Session variables comes handy sometimes, such that: