Actually, 14 sounds about right. Mapquest is very accurate in that even when you stop for food, gas, or whatever else, it usually takes about the amount of time they suggested. It takes us 16-17 hours to get from Allentown (north of Philly) to the Mouse. In October, it took us about 17.5-18 hours, and that was with me being sick *and* us stopping at South of the Border for an hour easily.
I'm about 2.5 hours from Annapolis, I think (about that far from Baltimore).... so 14 sounds right to me.
Plus don't forget, the speed limit on most of I-95 is 65, and in some spots it is actually 75. So going 75 to 80 mph (in the 75mph zones) is realistic.