due to smoother traffic flow the average speed was only reduced by 0.5 kilometers per hour.

Yeah, I wish people understood that, or even thought about it. So many seem to just speed by default. I’ve gotten some weird looks when I told that I always go 10 km/h below the speed limit on certain roads, because you get stuck in a slowdown anyways.
If there is any slowdown between you and your target, then driving fast will just get you stuck behind it sooner…