If you are reasonably fit then I would definitely walk it. It's really not far, there are moving walkways for chunks of it and best of all it's entirely predictable. So no sweating on missing the transit and waiting for another one.

Plus, when you arrive there will be no queues for the lifts and you can rise effortlessly up to gate level in one easy go.

Check the dashboard as suggested by our esteemed c-w-s.