Well, having lived within 20 miles of DC since 1960, minus military time, I can tell you there is just not a lot that can be done.
We probably have 10+ million commuters in/around and thru the area every day and there really is only 4 or 5 major roads with access to the area.
The roads have cars on them 24/7 unless the snow is so deep no one can get to the major roads so plowing/treating is very difficult.
We don't get enough snow to justify the large equipment that Minneapolis would have so the governments do they best they can with "right sized" equipment.
I worked a couple of years in Minneapolis and Albany NY and the difference between the DC area and our colder cities is our storms always either start as rain, end as rain or have rain sprinkled in with the snow which freezes. Minneapolis and Albany never got warm enough in the winter for the sleet/snow to melt and it just simply blew off the roadway.