2012 R2 Web Access Logon

Just trying to get a definitive answer to the age old question of can we remove the initial user logon requirements when accessing the RD Web Access server in a 2012 R2 RDS deployment?

I was under the impression that the Single Sign-On only removes the logon prompts when users try to access a RemoteApp or Session Host once they've logged on to the Web Access server?

Is there a way to use the current users credentials (they're all connecting from domain joined windows 7 or 8 machines) to logon to the RD Web Access site?

Cheers for now

Russell