I think the only way with no hills is to back track I81 North to I66 and go East to I95 then down to Myrtle Beach. Going SOUTH on I81 and pickup I64 to Richmond is another easy route but you will have to go DOWN the big long grade hill at AFTON MTN PASS. This is a very large Interstate with few curves but is a long grade going down hill.... Once you pass the Charlottesville Exit you are good to go East to I95 without too much worries.
On I95 SOUTH we always go two exits or so past South of The Border in SC on I95 and pick up US501 that takes you into the south part of Myrtle Beach. Great route for RV's... We usually stay at LAKEWOOD RESORT on Ocean BLVD with Family there so be sure to follow the hugh BILLBOARD SIGNS for LAKEWOOD off of US501 to bypass most of the the town before getting US17 Bypass...
Roy Ken
My Posts are IMHO based on my experiences - Words in CAPS does not mean I am shouting
Roy - Carolyn
RETIRED DOAF/DON/DOD/CONTR RADIO TECH (42yrs)
K9PHT (Since 1957) 146.52M
2010 F150, 5.4,3:73 Gears,SCab
2008 Starcraft 14RT EU2000i GEN
2005 Flagstaff 8528RESS