Terminal 5

Terminal 5Whilst travelling back through London last week, I noticed this new sign showing the extension of the London Underground Piccadilly Line that will take passengers to the new Heathrow Terminal 5 that is being built.

The only thing is, it's really confusing. If you were to look at that, how would you expect to get from the city to Terminal 5, considering trains appear to go straight from Terminal 4 to Terminals 1,2,3, bypassing T5 completely. If that's not going to confuse bewildered tourists, I don't know what will.