The trucks gain/gather 'speed' as they drive down the hill. = The trucks pick up 'speed' as they drive down the hill. [=the trucks go faster as they drive down the hill]
He types at a 'speed' of about 50 words per minute. = His typing 'speed' is about 50 words per minute.
Let me 'bring you up to speed' on our plans. [=let me tell you about the changes in our plans]
(..) with a load of fancy new toys from Fox. What about when you come up against him? What then? - I'll fight harder. I always have. - Take a look. His speed... his ferocity, his training.... I see the power of belief. I see... the League of Shadows resurgent. - You said he was excommunicated. (..)2012 The Dark Knight Rises