Automatic redirection to the splash page is depending on how the operating systems behave. Most of them are popping up a browser window for the splash page when they detect that login is needed (this is the behaviour of newer operating systems like iOS, Android). This behavior can also be changed by the user on some OS For example on iOS if auto login is turned off then the splash screen wont pop up. (Here is an article from Apple about this behavior)
But this is working differently with other operating systems and this behavior is out of our scope.
If the user is not logged in and the splash page is not displayed automatically, the user can open a browser and go to a page that starts with http:// like www.cnn.com . This way he will be redirected to the splash page.