Am relocating to Baltimore in early January for work. I work at a school, so it's not always easy to just take off a few hours early.

Trying to plan a couple of trips, involving flying out of the BWI/IAD/DCA area to catch either a long-haul domestic or international flight, say from ORD. I need to get an idea of what's realistic in terms of flying out after work.

If I get off work (northeast corner of Baltimore City) around 3:30-4:00, how long to get to IAD or DCA, if BWI flights aren't an option?? Or, if I get off work at XXX time, then I should not plan to fly out of DCA by YYY time, or by IAD by ZZZ time?

Thanks in advance for the help!