The best way to cope with traffic is actually to make multi-lane highways smaller, not bigger. Several long-term studies have shown that "road diets" that shrink 4-line highways to 3-lane highways significantly decrease traffic jams and accidents. Atlantic's CityLab has the story.
I haven't read this yet. But I noticed that on a week we all had to drive slower I got to work sooner. My husband has to drive a lot for work, so I would not like to see most speed limits go down all the time, but maybe if big cities gradually reduced the speed limit at rush hour and then back to normal that would be a good thing.
And if people would just stop changing lanes so much. If you really have a long drive, all this lane changing at most will save you five minutes, but its more likely to cause accidents or get you pulled over and such.