Ford and Vanderbilt are looking at what causes phantom jams, and we figure out why lane expansion isn’t really successful.
— Read on www.cnet.com/roadshow/news/traffic-talk-ford-vanderbilt-2018/

In my opinion the paragraph that mentions ramp metering etc is the key.

The fact that people don’t know how to merge, or others won’t let them merge, or my favourite, those that believe that moving a lane over so that they don’t have to “let” someone merge cause that .000001 second it takes to do so is worth cutting someone else off in the lane next to them so they don’t have to let someone merge are the causes of traffic jams etc.

Fix the “merge problem” and you will solve the traffic problem.