It's not the whole east, it's the Mid-Atlantic/Southeast region.
I think DC suffers a bit more dramatically because 99% of the population lives in the suburbs and has to drive/walk/train (often all three) into the city on a road and rail network built to handle a tenth of the current population.
Maybe my figures are wrong. 550,000 live in DC, 4-5 million in the suburbs. The Beltway and major roadways date from, what, the 1960's, and Metro dates from the 1980's. The population then was 1-2 million. No major work on the infrastructure has been done since then, just a constant slew of improvements on the various "mixing bowls."
So take that sort of environment and sprinkle a tiny bit of ice over it.