I85 is at least a 4 lane divided interstate highway. From I65 in montgomery, al to I95 in virginia. Montgomery to Myrtle Beach is I85 north to 285 east, Atlanta perimeter, to I20 east to I95 at Florence Sc, then I95 north about 10 miles to Myrtle Beach exit, Then east. I85 & I20 no mountains just rolling hills. Time your 285 part, before 6am, 10-2pm, after 6pm weekdays or most times on weekends. This is the least busy part of 285, but no picnic! You will go by the worlds busiest airport.