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]
(..) after what has been a momentous week for this company. Project Iccarus has increased our productivity... folds. Every department is working at three times usual speed... due to the increased interconnectivity of our... computer system! Computers! Computers! How could I talk about (..)2006 TvShow: The IT Crowd Title: Aunt Irma Visits Season: 1 Episode 6