Heading from Halifax toward Cape Breton Island (or vice versa), you need to choose between two basic routes. If you're burning to get to your destination, take Route 102 to Route 104 (the Trans-Canada Highway, the one with the maple leaf). If you're in no particular hurry and are most content venturing down narrow lanes, destination unknown, by all means allow a couple of days to wind along the Eastern Shore, mostly along Route 7. (Note that official tourism materials refer to this stretch as the Marine Drive instead of the Eastern Shore, for whatever reason.) Along the way you'll be rewarded with glimpses of a rugged coastline that's wilder and more remote than the coast south of Halifax. Communities here tend to be farther apart, less genteel, and stocked with far fewer services -- or tourists. With its rugged terrain and remote locales, this region is a good bet for those drawn to the outdoors and seeking coastal solitude.
Be forewarned that the Eastern Shore isn't breathtakingly scenic if you limit yourself to the main road. You'll drive mostly through cutover woodlands and scrappy towns. To get the most out of this section of the coast, become committed to making periodic wanders and detours, the more impetuous the better. Drive down dead-end roads ending in coastal peninsulas, where you might come upon wild roses blooming madly in the fog, or point your car inland to the enormous interior forest instead, where you can still find moose and an enveloping quiet.