I would echo Craig's comments [above] ;  slightly formal, but older people might well speak like that.

My version is as follows :

Asking the way:

A. Excuse me, could you tell me - is there a bus from here to Kensington High Street?

B. Yes, it's quite a way from here. You see the bus stop across the street? A 73* bus will take you right there.

A. Thanks a lot.

B. You're welcome.

* I used to take the 73 when I was a student at a college near Kensington High Street.  Changes to bus routes mean that the 73 has not served Kensington High Street for some years, and was replaced by the number 10 on this part of the route.

There really aren't learning resources when it comes to familiar casual language of this kind.  It's learnt through experience.

Bill is speaking [or writing] with irony when he says that  "in the rest of the country we still speak English"  -  he's 'making fun of' the way some people in the south-east use very informal expressions when perhaps the situation calls for a rather more formal response.

@Bill:

Thank you for your response. Be honesty, I don't understand exactly about the second part of your comment here. It is not your problem, it is mine. You know, as an intermediate level English learner, I don't know about "mockney" phrases? And what do you mean by " in the rest of the country we still speak English though expect "love" or "my ducks" to be added "?

Sorry for disturbing you with such a simple(for native speaker) question. 

Madam is very formal and might "jar", I'd avoid that.  bus-stop the hyphen is not needed.

Craig is correct in London and the south east the "mockney" phrases are used a fair bit, in the rest of the country we still speak English though expect "love" or "my ducks" to be added :-)

@Adrian:

Thank you for your comment here. In real life, there are many ways to express the same situation. But usually in textbook, there are only few formal expressions.  On the other hand, in real life, the English sentences seem not follow grammar laws tightly. I know that it is very common in a language. I don't mean that I want to face such complicated situations, instead, I welcome any challenges in English learning. But the question is how I can find an correct learning resource/materials and how I can grab them.