One option that was never fully planned was to connect the proposed Christiana DE I99 East Coast section and the existing Bedford PA I99 section by running I99 with the existing interstates I95, I476 and I76.
==Interstate 390 NY==
Interstate 390 would connect I 90 exit 8 in North Greenbush NY to VT Route 279 in Bennington VT The road was planned to travel as part of NY State Route 43 and then parallel to NY State Route 43; then parallel to NY State Route 351; then parallel to NY State Route 7 to VT Route 279 The only parts of the extension that have been built are VT Route 279 near Bennington VT and Route 43 between I-90 & US Route 4 in East Greenbush NY.
A more recent option on the plan would have the road travel along existing power easements in North Greenbush NY with the power lines placed below the road, so that existing homes and businesses would be unaffected.