Earlier quoted context omitted.
I don't think that's quite right. People in Dundalk will suffer a fair bit, as will folks in Glen Burnie and Annapolis, but most people are going from DC to Delaware, and go north rather than over the Key bridge. I think this is most harmful for commuters. Blocking the Baltimore harbor is brutal although I suspect the passage will be cleared as quickly as possible.
I think 30-35k cars a day cross that bridge. Being local to the area, is is going to make traffic in the entire metro area much worse, and it is already awful.
EDIT: That number seemed fishy; I think the reporter is referring to the traffic along the entire I-95 corridor.