The enroute controller
a) is expecting you to call at some point
b) already knows who you are
c) already knows where you are
so when you call, they are just thinking "ah, yup, theres ABC's taxi call". Most controllers are capable of registering that, even if they happen to be doing something else at the time. There are exceptions, depending on what they're doing, but in general, there's nothing that requires their full attention. So just launch straight into the taxi call. They'll give you traffic, and a code, and a clearance when it becomes available.
I've no idea why the AIP says we have to tell ATS which runway we're using.