I'm looking for the fastest way to get from London Heathrow Airport to Knightsbridge, London. Using Google maps, I found that the tube takes approximately 50 minutes. But are there any cheaper options? Maybe an express bus? Or a train?
Without any research I would say the tube is the cheapest and fastest as well, because you don't have to change at all to get to Knightsbridge. The Transport For London website says the journey is 42 minutes.
The Heathrow Express train, may take you faster into central London, but you have to change into the tube (District or Circle lines) at Paddington and then change again into the Picadilly line. That will take much longer.
There used to be a bus called they 'AIRBUS' going from Central London to Heathrow but it was discontinued in 2004.
Taxis and shuttle buses may be faster than the tube if there is very light traffic, which is not likely. They are surely more expensive.
Taking normal buses is possible, but you have to change at least twice and the journey takes at least two hours. It is the cheapest at £2.30, the tube is £5.30 (cash prices without an Oyster card). On the journeyplanner.tfl.gov.uk site, use advanced options, to specify that you don't want to use the tube and it shows you bus connections.
Two answers say the tube, but as a Londoner who does a similar journey regularly I beg to differ :) The answer is: it depends.
In light traffic (before about 6am in the morning), a taxi will take about 25 mins to do this journey (Google agrees). The same is true late at night (after 9pm). The taxi rank is also easier to get to at Heathrow than the tube station, from almost all the terminals, saving as much as 5-10 minutes in some cases.
At other times, the tube is likely the fastest option, as you won't have to change off the Piccadilly line. Getting there on the Heathrow Express is an option but the tube changes aren't great in this case.
The taxi is of course the most expensive option. But you asked for both the fastest way and the cheaper options, which don't align with each other :)
Without a doubt, the tube will be your fastest option in this case. The Piccadilly line goes straight there.
Express train goes to Paddington, at which point you'd have to change to the tube and come 1/3 of the way back!
Overland train also goes to Paddington. And a bus could take longer, depending on time of day.
Funnily, the tube is about the cheapest option - should be less than 5 pounds with an Oyster, although prices went up this year, so not sure of exact value. Bus is the cheapest, but will take longer, and you'd likely need to go to Hammersmith first and then change.