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]
(..) And when this happens, and when we allow freedom to ring... when we let it ring from every village and every hamlet, from every state and every city, we will be able to speed up that day when all of God's children, black men and white men, Jews and Gentiles, Protestants and Catholics, (..)2017 TvShow: The Walking Dead Title: Rock in the Road Season: 7 Episode 9