In other words you're saying that they're closely packed. If the distance between cars is reduced by 50% and their speed has reduced 10-15%, the throughput of that section of road has increased substantially.
As you said, it's speed differential and the use of brakes that causes traffic jams. By that reasoning, the left lane should go the same speed as the right. That would also discourage the use of lane changes which is generally what causes people to use their brakes on the freeway...
And remember the square law of braking. Because the safe following distance increases so much when you increase speed, faster speeds on the freeway decrease throughput rather than increase it.
If the far right or middle lanes are traveling faster than the left and also moving smoothly then someone’s doing it wrong.
Got an article to explain this? It seems counter-intuitive.
Following distances should be based on time, not physical distance. It shouldn't matter if cars are going 30 mph or 300 mph. If everyone maintains a 3 second following distance, there should still be a throughput of 20 cars per minute.
http://www.adventures-in-education.com/math/StoppingDistance...