Roadmap portal uses service desk customer accounts for customer users to log in. This ensures the security/safety of your customer data. On the top right corner of the roadmap portal, there is a link to Login/Sign Up.
Clicking on that link, takes the user to the service desk login page. Post successful login, user is brought back to the roadmap portal in logged in state.
You can tell the difference between a logged in & logged out user by looking at the top right corner.