Does the steady-speed method work, even with cooperation? The problem is usually people merging in front, requiring that everyone else slow down. I don't see h

Does the steady-speed method work, even with cooperation? The problem is usually people merging in front, requiring that everyone else slow down. I don't see how steady speed is even really possible there, let alone how it helps. Let's say everyone has a two-second following distance. Then each lane moves one car by every 2 seconds, and that's that.