If you opt to evacuate for an approaching hurricane, your direction of travel should hinge on the forecast track of the storm.
Most hurricanes approach southeastern North Carolina directly from the south (like Fran of 1996 and Floyd of 1999). In these events, the ideal evacuation route is a westbound route like I-40 west, US-74 west, US-76 west, and US-17 south to US-378 west (in the case of southwestern Brunswick County).
Occasionally, hurricanes approach the Carolinas more directly from the east (like Hugo of 1989 and Isabel of 2003). In such a case, a north or southbound mode of evacuation may be more appropriate (I-40 west to I-95 north, US-17 north or south, US-421 west, and NC-87 north or south).