JER - IAD, take JER-LGW-PHL and rent a car (if US Airways still operating it), depending where you want to get to around NW Washington/Dulles, its not a bad drive, have done it a few times.. just avoid the Beltway in the rush hour..
Alternately, connect to IAD or National through BOS.
Or better still... Flybe JER - SOU and rail-air link to LHR, you'd make the last two direct IAD flights out of LHR easilly then, avoid the M25 and the Washington Beltway!
