Try this site:
The I-95 Exit Guide | Travelers Alert Road and Bridge Construction
Also each state has a Department of Transportation site that will give you details about contruction projects.
If you are unfamiliar with the parking lot that is 95 in the D.C. area, let me suggest you avoid the hours of 6:00 am - 9:30 am and 3:00 pm - 8:00 pm in the D.C. vicinity. Horrible, horrible traffic coming down from Baltimore and even going south until you get past Alexandria/Fairfax County. Baltimore can be pretty messy as well during the same hours, although they tend to clear out sooner.
We also ran into what looked like long-term improvements in GA in December 08, so they are probably still going on. Some construction south of Jacksonville, FL as well held us up slightly. I would check online a couple of days before you are ready to leave. Take a good exit guide (we like Drive 1-95, available online and in bookstores) so you can get off if need be.
Just to add fun to everyone's trips, the state of VA is closing 19 rest stops to save money; they expect you to use McDonald's instead. This includes the ones in Dale City (Prince William County, where I live), meaning south of D.C., you will have to make it to Fredericksburg, VA to hit a potty. Good luck and welcome to the Old Dominion. Hope you have a strong bladder!
Safety Rest Areas and Welcome Centers