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]
(..) So we're up to dusk the night of the sinking. Six hours to go. Smith's standing there, the iceberg warning in his fucking hand,... ..and he's ordering more speed. years of experience working against him. He figures anything big enough to sink the ship they'll see in time to turn. (..)1997 Titanic
(..) So you've not yet lit the last four boilers ? l don't see the need. We are making excellent time. The press knows the size of Titanic. Now l want them to marvel at her speed. We must give them something new to print. This maiden voyage of Titanic... ..must make headlines. Mr lsmay, l would prefer (..)1997 Titanic