Rt 222 in Pennsylvania between Reading and Allentown is a highly traveled road that's mostly all two lanes (one lane each way) with traffic lights and much cross traffic.
PennDOT's solution is building circles at some of the intersections instead of upgrading it into a wider highway. Circles may help with flow, though that's debatable when one throws lots of big rigs into the mix, but doesn't solve the volume problem - two lanes carries a lot less vehicles than a four lane, limited access highway.
Among the main reasons for highways being needed, seemingly, most everywhere is the lack of planning. Though many states are now encouraging regional zoning; communities need to look beyond their borders when approving new construction.
Much of the challenge in building new highways is the lack of money combined with excess regulation that often greatly inflates the costs. For example, it took 40 years to expand Rt 222 between Reading, Pa to the Lancaster County line roughly 7 or so miles away - and that was even in despite of most all the land needed for it already being condemned decades before - so that wasn't the hold up. It was strictly environmental combined with lack of funds.
A similar issue occurred with the Blue Route near Philadelphia - another road that was started in the 1960s and then stopped for lack of funds, then held up by environmentalists until it was finally completed (though not as designed, which has caused problems ever since - 3 lanes merging into 2 at a very busy section) around 1990.
Rambling on, but in a nutshell, reducing the standard of living, which many environmentalists seem to advocate, isn't the answer. New and/or improved highways in many places *are* needed.