Could it be any other way? Could you design a road to induce acceleration and slow deceleration without affecting safety?
You see congestion up ahead, and you slow down to, say, 40mph. This creates some room in front of you in anticipation of the inevitable braking. You then drive through the traffic jam at a constant speed with no acceleration or deceleration, and the people behind you will have no choice but to follow (or change lanes which is the weak point of the solution) What you will see at the other end (if you could go back and look) is that you have dissolved the jam because you have prevented people from decellerating quickly and accelerating slowly.
Several people have tried this successfully and it works.
The problem however is not everyone will do this e.g. some people simply love to speed, and changing behaviour in people is harder than changing the rules they should follow.
Some of the projects successfully proved the concept in real world usage of the technology, but issues due to insurance (who will be liable in case of accidents) and infrastructure cost seem to be the main barriers at present.