It seems to me that localised use of language is a phenomenon that occurs everywhere. Basically people use words and phrases that those around them understand. If the understanding is there then language has been succesful in it's primary aim... to communicate.
''Hail a taxi'' and ''call a cab'' both mean the same thing. Although a taxi driver might not want to be associated with a cab driver as they have a different status. The general public couldn't really care. They know what they want.